JP4714005B2 - Digital type protective relay - Google Patents

Description

  The present invention relates to a digital type protective relay, and more particularly to a digital type protective relay in which signal transmission between an analog input unit and an arithmetic unit that performs protective relay arithmetic is improved.

  A conventional digital type protective relay takes in the output of an instrument transformer for detecting the amount of electricity such as an electric power system, converts the level of the amount of electricity and performs analog / digital conversion, an analog input unit, and a predetermined amount for the amount of electricity. The unit includes a plurality of units such as an arithmetic unit that performs protective relay calculation, an output unit that outputs a tripping trip command (trip output), and an input unit that inputs the state of an external device. The plurality of units are connected to a system bus (parallel bus), and data is exchanged between the units by signal transmission via the system bus (see, for example, Patent Document 1).

  The protection relay has a product use period longer than the supply period of the components constituting the protection relay because of the peculiarity of substation equipment that is used for a long period of 20 to 30 years in a substation or the like. Therefore, stable product supply for a long period of time is difficult unless the treatment range for parts renovation or failure or the design change range when the need for enhancement of the protection function arises. This localization is difficult with a hardware configuration of a protective relay tightly coupled to a conventional system bus.

  Therefore, the units of the functional units constituting the protective relay (analog input unit, arithmetic unit, input / output unit) are configured to be loosely coupled between the units with a serial transmission path, over a period of 20 to 30 years. Even if a specific unit needs to be replaced or a design change occurs due to a failure or enhanced protection function, it is possible to use other units as they are by simply replacing or redesigning the target unit. (For example, refer to Patent Document 2).

  In addition, in the “substation system using a serial bus” for the purpose of simplifying the substation system configuration, digitizing data, and using the data effectively through the network, a protection card and measurement / control for performing protection calculations There is also shown a form in which a card for performing the operation and a state detector for detecting the current / voltage of the system are connected by an optical serial bus, and the protection card is housed in an on-site cubicle of a transformer machine (see, for example, Patent Document 3). The state detector referred to here is a so-called electronic instrument transformer, and does not require an analog input unit provided in a conventional protective relay.

Japanese Patent No. 2694993 JP 2005-6385 A JP 2003-224932 A

  However, in Patent Document 2 and Patent Document 3, when a multi-line electric quantity is required, such as a transformer protection device, a busbar protection device, and a stabilization device (in Patent Document 2, a plurality of analog input units are provided. In Patent Document 3, when a plurality of state detectors are used, or when an amount of electricity such as a power system is required by a plurality of arithmetic units (for example, a main relay, an accident detection relay, an oscilloscope output device) , The failure point evaluation device or its terminal device) has the following two problems to be solved.

(1) 1st subject The serial cable which transmits detection values, such as an electric quantity from an analog input part, to a calculating part becomes enormous number, and the following problems generate | occur | produce in connection with this.
In contrast to the normal input / output signal (DC110V) of the protective relay, the serial transmission electric signal is a weak current of about DC ± 5V to ± 15V. In a device incorporating a protective relay, a serial cable and an input / output signal (DC 110 V) cable are wired in the same device, so care must be taken in wiring assembly such as separation of bundled wires.

  For this reason, optical serial cables may be used for the purpose of enhancing noise resistance. However, optical cables and optical transmission / reception units are expensive and not only economically deteriorate, but also stress and light quantity attenuation due to bending of optical cables. Take care in assembly. A large number of both electric cables and optical cables routed in the protective relay device involves a risk of deterioration in transmission quality.

  In addition, regardless of whether or not an optical serial cable is used, contact reliability decreases due to an increase in the number of connecting portions due to an increase in the number of cables. Furthermore, when replacing the unit from the apparatus, deterioration of maintainability such as detachment and curing of a large number of cables is inevitable.

(2) Second problem When a concentrator configuration is applied to a serial bus, the cable concentrator has the following problems. That is, in a device including a large number of analog input units, such as a transformer protection device, a bus protection device, and a stabilization device, sampling data is simultaneously transmitted to the arithmetic unit by sampling synchronization. When the serial bus is concentrated, the data transmitted at the same time is destroyed by the collision. Normally, even if there is a data collision, it is possible to transmit data reliably although it takes time by providing a retransmission request function or the like. However, a large delay in data transmission / reception due to data collision or retransmission function deteriorates the relay performance of a protective relay that requires real-time processing.

The present invention has been proposed in order to solve the above-described problems of the prior art, and its purpose is to apply a unique concentrator configuration (wiring topology) to the serial bus, thereby reducing the number of serial cables and cables. It is an object of the present invention to provide a digital protection relay that secures transmission quality and improves maintainability by simplifying routing.
Another object of the present invention is to provide a digital protective relay that efficiently performs data transmission / reception between an analog input unit and an arithmetic unit and secures excellent relay performance with respect to a unique concentrator configuration of a serial bus. There is.

In order to achieve the above-mentioned object, the present invention provides a digital relay for performing a protective relay calculation based on sampling data obtained by converting an analog electric quantity of an electrical equipment to be protected into a digital value and outputting a result of the protective relay calculation. In the type protective relay, the analog electrical quantity is sampled based on a sampling reference signal, and a plurality of analog input means for outputting sampling data converted into a digital value, and an arithmetic means for performing at least the protection relay calculation, The sampling data transmission system from a plurality of analog input means to the arithmetic means is constituted by a serial bus having at least a part of a common part, and serial transmission of each sampling data in the plurality of analog input means is the common part. In the predetermined time without any data collision, the calculation means As will be received, a switch for introducing the sampling data for each analog input means to said common unit, synchronizes the switching of the switches for each of the analog input unit to the reference signal for the sampling of the protective relay computation It is characterized by having a bus switch function for controlling switching of all the switches within a cycle .

  Further, the sampling data transmission system between the arithmetic means and the plurality of analog input means is constituted by a star type or multidrop type topology of 1 to N transmission. The arithmetic means comprises a main relay arithmetic means and an accident detection relay arithmetic means, the analog input means comprises a main relay analog input means and an accident detection means analog input means, and the main relay arithmetic means and a plurality of mains A sampling data transmission system between the relay analog input means and the analog input means for a plurality of accident detection means is configured with a star type or multi-drop topology of 1 to N transmission. One of means for solving the problems in the present invention is to configure the sampling data transmission system in the star topology or multi-drop type of 1: N transmission.

  Further, each sampling data received via the serial bus from the plurality of analog input means is received by the arithmetic means in a fixed order by the bus switch control, and has the bus switch function and the Bus switch means having a common part for collecting serial buses, the bus switch means generates a reference signal for sampling, generates control timing of the switch based on the reference signal for sampling, and A sampling reference signal is distributed to at least the plurality of analog input units, and the plurality of analog input units generate a predetermined sampling timing based on the input sampling reference signal and perform sampling of the analog electric quantity In order to solve the problems in the present invention It is one of the stages.

  According to the present invention having the configuration as described above, the transmission system between the analog input means and the relay calculation means is configured by a star topology or a multi-drop topology, thereby greatly reducing the connector connection portion of the serial transmission cable. it can. In addition, since the bus switch synchronizes with sampling and controls the switch without data collision, the arithmetic unit can acquire the electric quantity efficiently and safely and reliably, and can ensure the relay performance.

  Hereinafter, some of the best modes for carrying out the present invention will be sequentially described. In the description, first, a plurality of embodiments related to the wiring topology of the transmission system of each unit constituting the digital type protective relay will be described, and then the specific configuration and operational effects of each unit used in each embodiment will be described. State.

1. Overall Configuration and Wiring Topology (1) First Embodiment Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, functions and parts (for example, a power source for driving a circuit) that do not need to be described are not shown in the description of the features of the present invention.

  FIG. 1 shows a functional block diagram of the digital protection relay 1a of the first embodiment. In FIG. 1, the digital protection relay 1a includes analog input units 121 to 12n, analog input units 131 to 13n, an arithmetic unit 11, bus switches 141 and 142, and an input / output unit 15.

  The analog input units 121 to 12n are used for the main and information terminals, input voltage and current electric quantities AI21 to AI2n from the protection target equipment of the power system, and perform analog / digital conversion. The analog input units 131 to 13n are used for accident detection and information terminals, and input voltage and current electric quantities AI31 to AI3n from equipment to be protected in the power system, and perform analog / digital conversion.

  The arithmetic unit 11 includes a main relay arithmetic unit 111 that performs a main relay calculation based on sampling data of the electric quantities AI21 to AI2n, and an accident detection relay arithmetic unit that performs an accident detection relay calculation based on the sampling data of the electric quantities AI31 to AI3n. 112, the oscilloscope function and the terminal function for the external failure point rating device are executed based on the sampling data of the electrical quantities AI21 to AI2n and the electrical quantities AI31 to AI3n, and the oscilloscope data and the information necessary for the external failure point rating device It is comprised from the information terminal unit 113 which outputs DOL outside.

  The bus switch 141 relays signals transmitted and received between the main relay arithmetic unit 111 and the information terminal unit 113 and the analog input units 121 to 12n, and collects serial cables S121 to S12n, which are transmission media for the signals, The main relay operation unit 111 is connected via the cable S141a, and the information terminal unit 113 is connected via the serial cable S141b. The bus switch 142 relays signals transmitted and received between the accident detection relay arithmetic unit 112 and the information terminal unit 113 and the analog input units 131 to 13n, and collects serial cables S131 to S13n that are transmission media of the signals, The accident detection relay arithmetic unit 112 is connected via the serial cable S142b, and the information terminal unit 113 is connected via the serial cable S142a.

  The input / output unit 15 is connected to the main relay arithmetic unit 111 via the cable IO1, is connected to the accident detection relay arithmetic unit 112 via the cable IO2, inputs information DI1 from an external device, and outputs a control command DO1 to the outside. Is output.

  In the figure, external devices and devices are not shown. It goes without saying that each unit constituting the protective relay 1a of FIG. 1 can be implemented not only in a unit form but also in any form and combination such as a printed circuit board and an IC (integrated circuit) form. Transmission using a serial cable can be applied to either half-duplex communication or full-duplex. In the case of full-duplex communication, transmission / reception arbitration is unnecessary. Further, as a physical form, transmission and reception may be configured by separate cables. Moreover, both an electric cable and an optical cable can be applied as the cable.

  In the first embodiment, in the main relay arithmetic unit 111 and the accident detection relay arithmetic unit 112, analog input units 121 to 12n, 131 to 3n, serial cables S121 to S12n, S131 to S13n, S141a, S142b, and a bus switch 141 are used. , 142 and cables IO1 and IO2 are separated from analog input to output necessary for the protection relay function. This ensures the independence of the accident detection relay, which is positioned as fail-safe with respect to the main relay, even when serial transmission or serial communication is applied to capture the amount of electricity. This is a configuration that does not affect the normal operation on the detection side and vice versa. In order to ensure reliability, the protective relay is generally composed of a main relay and an accident detection relay. Accident detection relays are also called fail-safe relays.

  Further, the information terminal unit 113 is used on the main side for the purpose of simplifying the serial bus while considering the case where it is necessary to take in the electric quantity from all the analog input units 121 to 12n and 131 to 13n. The analog input units 121 to 12n, the serial cables S121 to S12n, the bus switch 141, the analog input units 131 to 13n used on the accident detection side, the serial cables S131 to S13n, and the bus switch 142 are shared.

Therefore, the topology of the serial bus between the analog input units 121 to 12n and 131 to 13n and the arithmetic unit 11 in this embodiment is summarized as follows.
-Between the main relay arithmetic unit 111 and the analog input units 121 to 12n is "star topology with 1 to N transmission"
-Between the accident detection relay arithmetic unit 112 and the analog input units 131 to 13n is "star topology with 1 to N transmission"
· Between the information terminal unit 113 and the analog input units 121 to 12n and 131 to 13n is "two star topology with 1 to N transmission"

  The star topology employed in the first embodiment having the above-described configuration is particularly effective as N increases. That is, FIG. 2 shows a case where a one-to-one topology (referred to as Point-To-Point connection) is applied. FIG. 2 illustrates a case where six main analog input units 121 to 126 and two accident detection analog input units 131 and 132 are used. In this case, since 16 serial cables are required for the serial transmission system SN1 and both ends of the cable are connectors for the unit, there are 32 connector connection portions. On the other hand, when the star topology of this embodiment is applied to the same number of devices, as shown in FIG. 3, the serial transmission systems SN2 and SN3 are combined, 12 serial cables, and the connector connection portion is It can be seen that it has been reduced to 24 places.

(2) Second Embodiment FIG. 4 shows a second embodiment of the present invention. In the second embodiment, the serial cable connection between the bus switches 141 and 142 and the arithmetic unit 11 is replaced with copper foil wirings (hereinafter referred to as patterns) P1 and P2 of the printed boards BA1 and BA2. The signal path can be easily branched by the patterns of the printed circuit boards BA1 and BA2. As a result, the number of serial cables is reduced to 8 and the connector connection portion is reduced to 22 locations. Further, by using the printed circuit boards BA1 and BA2 as backboards on the back side of the case of the protective relay 1a, the arithmetic unit 11 or the units 111, 112, and 113 in the arithmetic unit 11 can be easily detached without connecting or disconnecting cables. Can be structured. Needless to say, the maintainability (unit exchange, etc.) of each unit 11, 111, 112, 113 is improved.

  In FIG. 4, the printed circuit boards BA1 and BA2 are separated for the main side and the accident detection side. This is intended to enhance the independence of the two, but the printed circuit board is only a pattern and has high reliability. Furthermore, a common printed circuit board BA3 may be used for main and accident detection as in the modification shown in FIG. Note that the printed circuit board (BA1, BA2, BA3) can use a flexible substrate or the like to improve the degree of freedom of the structure of the protective relay 1a.

(3) Third Embodiment FIG. 6 shows a third embodiment of the present invention, and this embodiment does not include the information terminal unit 113. Since other configurations, operations, and effects are the same as those in the first embodiment, description thereof will be omitted. Needless to say, the protective relay 1b can be configured even if the information terminal unit 113 is not provided.

(4) Fourth Embodiment FIG. 7 shows a fourth embodiment of the present invention.
In the protective relay 1c, if there are few analog inputs on the accident detection side, one analog input unit may be sufficient. However, it depends on the number of input channels of the analog input unit. In this case, only the serial cable S131 for transmitting electricity is sufficient. Since data collision cannot occur, the bus switch 142 is unnecessary (there is no problem even if a bus switch is provided). The fourth embodiment is a configuration example in which the bus switch 142 is not provided. In such a configuration, switch switching control is performed only on the main side.

  Also in this embodiment, the same effect as in the first embodiment is exhibited. That is, in the case of FIG. 7, the accident detection relay arithmetic unit 112 includes a sampling reference signal generation unit in its own unit and distributes the sampling reference signal to the analog input unit on the accident detection side. The main relay arithmetic unit 111 may also be provided in the own arithmetic unit 111 without providing the sampling reference signal generator 1413 in the bus switch 141. Even if the sampling reference signal generator is not provided in the bus switch, the same effect as that of the first embodiment can be obtained if it is provided in any of the functional units in the protective relay. When the information terminal unit 113 is provided without using the bus switch 142, the information terminal unit 113 acquires the electric quantity data on the accident detection side in the arithmetic unit 11 via the accident detection relay arithmetic unit 112. .

(5) Fifth Embodiment FIG. 8 shows a fifth embodiment of the present invention. The feature of this embodiment is an example in which the arithmetic unit is duplicated, and the analog input units 121 to 12n on the main side and the analog input unit 131 on the accident detection side are shared. Note that the analog input unit 131 on the accident detection side is illustrated, but the same applies to a plurality of units. Another feature of the present embodiment is that each of the analog input units 121 to 12n, 131 includes two serial output ports for electrical quantity data. The main relay arithmetic unit 111 in the arithmetic unit 11a is constituted by a single star system with serial cables S121 to S12n, and the accident detection relay arithmetic unit 112 is constituted by a one-to-one topology of the serial cable S131. Description of the information terminal unit 113 is omitted.

  The main relay arithmetic unit 111 in the arithmetic unit 11b is constituted by a star-shaped system of serial cables S121a to S12na, and the accident detection relay arithmetic unit 112 is constituted of a serial cable S131a in a one-to-one topology. Description of the information terminal unit 113 is omitted.

  In this embodiment, the analog input unit is shared between the two arithmetic units, which is advantageous in terms of cost. For example, it is particularly effective for a duplex configuration of a transformer protection relay (commonly referred to as a main-main configuration), a collective unit of a bus protection relay, a configuration of a split unit, or the like.

(6) Sixth Embodiment FIG. 9 shows a sixth embodiment of the present invention. In this embodiment, a switch function is added to an analog input unit, so that a multi-drop type (also called a bus type) is provided. This topology is configured in a protective relay. That is, in each of the above embodiments, the transmission topology in which the arithmetic unit side acquires the amount of electricity is a star shape, whereas in FIG. 9, the protective relay is configured with a multi-drop topology. Even in this case, the main-side serial transmission system MS and the accident detection-side serial transmission system FS are separated from each other, and the independence of the main and the accident detection is maintained. In this case, it can be seen that the number of cables is limited to ten.

  Further, the multidrop cable wiring between the analog input units in FIG. 9 may be a pattern such as a backboard (printed circuit board) of a case for housing the unit. The same applies to the multidrop cable wiring in the arithmetic unit 11. In this topology, the bus switch 141 mainly having a concentrating function is not required. Since the analog input units 121 to 126, 131, and 132 are synchronized with each other for distribution of electricity, the multi-drop topology has a shared portion in the transmission medium. There is a risk of collision and destruction. However. This can be avoided by using an analog input unit having a switch function. Details of the analog input unit having the switch function will be described later with reference to FIG.

(7) Seventh Embodiment FIG. 10 shows a seventh embodiment of the present invention. In this embodiment, a pair of sampling data transmission systems between the arithmetic means and the plurality of analog input means is provided. It is characterized by a multi-drop topology with N transmission and a star configuration topology. That is, as shown in FIG. 10, the transmission rate (transmission load) of the sampling data transmission system can be reduced by using a multi-drop type combined with a star type. Assuming that the transmission rate in the case of the multi-drop configuration is 100 Mbps, the transmission rate can be reduced to 1/3 because the transmission system is divided into three in the star configuration SN3 in FIG.

  If all terminals 121 to 129 and the arithmetic unit sides 111 and 113 are configured in a star configuration, the transmission speed can be minimized, but the transmission cable and the input port of the transmission input processing unit on the arithmetic unit 111 and 113 side are correspondingly reduced. Increase in hardware size. The combination of multidrop and star offers the best balance for transmission speed and hardware-scale tradeoffs.

(8) Other Embodiments Although the embodiment of the serial transmission system has been described above, depending on the protective relay, there are other examples as follows, and it goes without saying that the above embodiments can also be applied to these.
・ Protective relay without accident detection relay operation unit.
-A protective relay that implements an accident detection relay and main relay in one unit (in this case, serial input of electricity is shared with accident detection and main).
・ Protective relay with multiple main relay operation units.
・ Protective relay equipped with multiple accident detection relay operation units.
A protection relay provided with a plurality of information terminal units of “present” and “not present” in the above four forms of protective relays.
-Any combination of the above 6 types of protective relays.

Furthermore, although the serial bus transmission medium has been described with a pattern of a cable or a printed circuit board, the transmission medium is not limited to a wired line because each analog input unit has a switch function. The serial signal transmission / reception unit may be replaced with a wireless interface, and the serial bus may be configured wirelessly.
(9) Effects of each embodiment

  As described above, according to each of the above embodiments, since the function unit for obtaining the amount of electricity and the transmission system for the amount of electricity are separated on the main side and the accident detection side, the independence of the main and the accident detection is ensured. The other side is affected by a malfunction, etc., causing a malfunction as a protective relay (giving a trip trip command to the protection target even if it is not an accident), malfunctioning (issuing a trip trip command to the protection target in the event of an accident) Not) can be avoided.

  In addition, the transmission system for the quantity of electricity is separated on the main side and the accident detection side, and each transmission system is configured with a star topology or multidrop topology, greatly reducing the serial transmission cable and its connector connection. it can. This is more effective as the number of analog input units increases. In the device incorporating the protective relay, the complexity and routing of the cable wiring is improved, the risk of contact failure of the connecting portion is reduced, and the quality and maintainability are improved.

  In addition, the number of analog input units is significantly increased when there are bus protection relays and transformer protection relays, as well as mains-integrated transmission line protection relays (one main protection PCM relay and one rearrangement protection distance relay). It is needless to say that the present embodiment can be applied to all types of protective relays regardless of the number of analog input units.

  In this embodiment, a protection relay can be realized with the same functional configuration (configuration of a bus switch, an arithmetic unit, and an input / output unit) regardless of the number of analog input units and regardless of the size of the protection scale. That is, even if the protection scale is increased, it is not necessary to increase special hardware (communication interface, etc.) accompanying the expansion of the analog input.

  Conventionally, a protective relay and a line controller (which often has a measurement function as a relay that inputs a selection / control signal command from a host system and outputs a control signal to the corresponding power device) are configured with the same hardware. There are many cases. This is because the protective relay hardware can also be used as a line controller. Naturally, the protective relay of this embodiment can also be applied as a line controller.

  Since the information terminal unit is configured as two systems of star type or multi-drop type topology of 1 to N transmission with respect to the analog input unit on the main side and the accident detection side, even if this information terminal unit is added, it is 1 to 1 Compared to the topology, the serial transmission cable and connector connection can be greatly reduced.

  The main function of the bus switch of this embodiment can be incorporated in a custom IC or the like, and can be easily downsized. Further, the number of cables and the number of connectors can be further reduced by patterning the serial transmission system between the bus switch and the arithmetic unit with a printed circuit board. Further, by using the printed board as a backboard of the arithmetic unit, the main relay arithmetic unit, the information terminal unit, and the accident detection relay arithmetic unit are connected to the backboard by a connector. As a result, each unit can be easily detached from the front (front maintenance), and maintainability of unit replacement is also improved.

2. About each unit Next, the detail of each unit currently used in each said embodiment is demonstrated concretely according to illustrated embodiment.

(1) Information terminal unit 113
The information terminal unit 113 in FIG. 1 will be described in detail. The information terminal unit 113 is roughly divided into an oscilloscope output function and a terminal function of the failure point rating device. The oscilloscope output function is a function that provides waveform data (oscilloscope) of voltage and current of the power system, and in particular, provides data necessary for analyzing the situation at the time of a system fault. The failure point evaluation device evaluates the failure point at the time of a system fault. This requires voltage and current data of the power system at the time of the accident, so voltage and current data are sucked up from terminals at various places in the power system. This terminal function is to freeze (hold) the voltage and current data of the power system as in the oscilloscope output function, and to provide the data upon request.

  In the present embodiment, the protection relay inputs the electrical quantity of the current and voltage to be protected in various places in the system, so that the electrical quantity data is used as it is for oscilloscope and failure point evaluation data. In FIG. 1, the analog input is separated for main and accident detection. The amount of electricity required for the main and the amount of electricity required for accident detection vary depending on the protection relay element. Therefore, since the amount of electricity input on the main side may not be sufficient for oscilloscope output and failure point evaluation, it is also necessary to acquire the amount of electricity input on the accident detection side.

  From the above, the information terminal unit 113 is configured to be able to take in electricity from both the analog input units 121 to 12n on the main side and the analog input units 131 to 13n on the accident detection side. When the amount of electricity required by the information terminal unit 113 is sufficient from the data from the analog input units 121 to 12n on the main side, the information terminal unit 113 passes from the analog input units 131 to 13n on the accident detection side via the bus switch 142. Needless to say, it is not a condition to connect to the transmission system. Similarly, when the data from the analog input units 131 to 13n on the accident detection side is sufficient, the connection with the transmission system on the main side is not a condition.

  The information terminal unit 113 has a communication function in order to transmit information (electric amount data or the like) DOL necessary for an external failure point evaluation device, an external oscilloscope device, or the like. This communication includes serial communication such as RS232C, RS485, and Ethernet.

  Since the information terminal unit 113 performs data freezing (holding) at the time of an accident, it is necessary to capture information (such as relay operation information on the main side and the accident detection side at the time of the accident determination). Although not shown, the arithmetic unit 11 may be provided with a signal bus capable of transmitting and receiving information between the main relay arithmetic unit 111 and the accident detection relay arithmetic unit 112 and the information terminal unit 113. Further, when not taking relay operation information or external information (breaker opening / closing, etc.) from the main relay arithmetic unit 111 or the like, although not shown, a signal bus capable of transmitting and receiving information between the input / output unit 15 and the information terminal unit 113 (Serial connection or parallel connection) may be provided and taken in from the input / output unit 15.

  In the conventional failure point evaluation device, there is also a device that evaluates the failure point only with the electric quantity data of the local line of the system. In order to realize this device with the protective relay 1a of the present embodiment, the information terminal unit 113 is not an external failure point evaluation device but only has a failure point evaluation function.

In the above, the oscilloscope output function and the terminal function of the failure point evaluation apparatus have been described, but in addition to these, the following functions can be implemented.
-It has a relay settling function and a function of communicating using an external portable operation means (also called a portable HI, which corresponds to a personal computer or a dedicated portable terminal) and Ethernet (trade name). As a result, the set value can be written and read by operating the screen of a personal computer or the like. With this portable operation means, relay operation information and device abnormality information can also be viewed. When this function is provided in the information terminal unit 113, although not shown in FIG. 1, a signal bus that can send and receive information between the main relay calculation unit 111 and the accident detection relay calculation unit 112 and the information terminal unit 113 is calculated. It will be provided in the unit 11.

(2) Analog input units 121 to 12n, 131 to 13n
In each of the embodiments, the analog input electricity quantities AI21 to AI2n and AI31 to AI3n input to the analog input units 121 to 12n and 131 to 13n are converted into digital values. An example of the configuration of the analog input unit 121 is shown in FIG. 11 as a representative.

(2-1) Sampling of analog input amount The analog input unit 121 is supplied with voltage from the current amount AI211 and the current transformer PT1 from the current transformer CT1 provided in the electrical equipment (transmission line B) constituting the power system. Enter the quantity AI212. This input electric quantity (alternating current) is a three-phase current, a zero-phase current, a three-phase voltage, a zero-phase voltage, or the like. The amount of electricity required for each line varies depending on the protection element. The electric quantities AI211 and AI212 in the figure are two quantities, but this is an example.

  The analog input unit 121 includes auxiliary instrument current transformers 1211a and 1211b and auxiliary instrument transformers 1211c and 1211d. These are connected to AC1, AC2, AP1, AP2 with analog filters 1212a to 1212d for high frequency elimination. Further, the high-frequency removing analog filters 1212a to 1212d are connected to the sample-and-hold circuits 1213a to 1213d AF11 to AF14. The sample and hold circuits 1213a to 1213d are connected to the multiplexer 1214 and connected to the connections h1 to h4.

The operation of sampling an analog quantity will be described.
The auxiliary instrument current transformer 1211a converts the input electric quantity AI211 into a current value at a level that can be handled by an electronic circuit. The filter 1212a has a cutoff frequency characteristic larger than that of the fundamental wave (50 Hz or 60 Hz), and removes high frequency components. The sample and hold circuit 1213a simultaneously holds (sampling synchronization) all the analog input electric quantities from which the high frequency has been removed by predetermined sampling. The holding values of the plurality of sample-and-hold circuits 1213a to 1213d (that is, the holding value of the electric quantity obtained from each analog channel) are sequentially output to the analog / digital conversion unit 1215 (AM1) by switching the internal switch of the multiplexer 1214. Is done. The filter 1212a is not limited to an analog filter, and may be substituted by providing a digital filter for digital data after analog / digital conversion.

  In addition, the sample and hold circuit of FIG. 11 is located in the preceding stage (analog input side) of the multiplexer 1214, but there are other forms. This is shown in FIG. In FIG. 12, the sample and hold circuit is located at the subsequent stage of the multiplexer 1214. In FIG. 12, other functional units and connections are similar to those in FIG. In FIG. 12, the filters 1212a to 1212d are directly connected to the multiplexer 1214, AF11 to AF14, and a sample and hold circuit 1213 is provided for the output of the multiplexer. The output of the sample and hold circuit 1213 is connected to the analog / digital conversion unit 1215 (h). Note that an analog / digital conversion unit (function unit 1215B in the figure) having a built-in sample and hold circuit may be applied.

  The above configuration example is equivalent to the analog input unit of the conventional protective relay, and can be applied to this embodiment. In the analog input unit, when the above-described sample and hold circuit is located at the subsequent stage of the multiplexer as shown in FIG. 12, the sampling timing of each analog input amount to be held and analog / digital converted is the switching time of the multiplexer. I can't tell. Since this time lag is corrected by relay calculation processing or the like, it can be said that sampling of analog input is synchronized even in such a case. Therefore, the analog input unit of the first embodiment and the second embodiment to be described later is included as an embodiment regardless of whether the sample & hall circuit is located at the front stage or the rear stage of the multiplexer.

(2-2) Digital Input / Output Next, digital input / output (serial communication) in the analog input unit 121 will be described.
The data addition unit 1217 adds the data d1 to d3 of the additional code generation unit 1218, the terminal ID storage unit 1219, and the calibration value storage unit 121c to the analog / digital converted electrical quantity data AD1. The additional code generation unit 1218 generates an error detection code CRC (d1) and the like. Although not shown in FIG. 11, not only the electric quantity data AD1, but also the terminal ID value (d2) and the calibration value (d3) are input to the additional code generation unit 1218, and the electric quantity data AD1, the terminal ID value, and the calibration are input. An error detection code CRC (d1) for all data of values is generated.

(2-2-1) Setting of terminal ID For identification when there are a plurality of analog input units, a terminal identification code (referred to as a terminal ID for short) may be required. In this case, a setting unit 121A for setting the terminal ID is provided and stored in the terminal ID storage unit 1219. The terminal ID value (d2) is taken out from the terminal ID storage unit 1219 and added to the electric quantity data AD1. The arithmetic unit 11 takes in the electric quantity data AD21 and can identify the transmission source terminal of the electric quantity data AD21 from the terminal ID value. The setting unit 121A can be easily set manually by using a setting mechanical switch (such as a rotary switch or a dip switch).

  There is also a method for automatically setting instead of manually. A configuration example of this automatic setting (applicable for both main and accident detection) will be described with reference to FIGS. These are configurations that are automatically set by attaching an analog input unit to the storage case.

  In FIG. 13, a printed circuit board board BA4 such as a backboard is provided on the back side of the storage case. In the printed circuit board board BA4, a DC voltage P5 is applied, and a pattern PA of the voltage signal is formed on the platform. Now, connectors are mounted (not shown) at positions where each unit is mounted on the analog input units 121a to 124a having an automatic setting function. Pins PI1 to PI16 exemplify connector pins. The pins PI5, PI9, PI10, PI13, PI14, and PI15 are not connected to the voltage signal pattern PA.

  FIG. 14 shows a configuration in which the analog input unit 121a is attached to the storage case (the printed circuit board BA4 is a cross section). The printed circuit board BA4 and the analog input unit 121a are connector-fitted (CON), and voltage signals SD1 to SD4 are input from the connector pins PI1 to PI4 to the ID setting unit 121A. The ID setting unit stores the terminal ID value d6 in the terminal ID storage unit 1219 based on the values of the voltage signals SD1 to SD4.

In the voltage signal pattern configuration shown in FIG. 13, each of the analog input units 121a to 124a reads the following voltage signals SD1 to SD4. The voltage signal “present” or “not present” is represented by a digital value of 1, 0.
-Reading value of analog input unit 121a (SD1, SD2, SD3, SD4) = (1, 1, 1, 1)
・ Read value of analog input unit 122a (SD1, SD2, SD3, SD4) = (0, 1, 1, 1)
・ Read value of analog input unit 123a (SD1, SD2, SD3, SD4) = (0, 0, 1, 1)
・ Read value of analog input unit 124a (SD1, SD2, SD3, SD4) = (0, 0, 0, 1)
In this way, a value unique to each unit can be read, and thus a unique terminal ID can be automatically set.

A modified example of the automatic setting configuration shown in FIGS. 13 and 14 will be described with reference to FIGS. 15 and 16.
In FIG. 15, a steel plate BT1 (application example is not limited to a steel plate) is provided on the back side of the storage case. In the steel plate BT1, switch pressing pins PH1, PH2, PH3, and PH4 are arranged so as to be shifted in accordance with the mounting position of the analog input unit. FIG. 16 shows a configuration in which an analog input unit 121b having an automatic setting function is mounted in a storage case (the steel plate BT1 is a cross section). On the back surface of the unit 121b, through holes HO1 to HO4 are provided at positions in the height direction where the switch pressing pins PH1, PH2, PH3, and PH4 can be inserted. Mechanical switches SWA to SWD are provided in the unit 121b at the positions of the through holes HO1 to HO4. In the same figure, by attaching the unit to the storage case, the pin PH1 of the steel plate BT1 pushes the switch SWA through the through hole HO1. Thereby, the switch SWA is closed, and the voltage signal of the internal DC voltage P5 is input to the ID setting unit 121A.

  As shown in FIG. 15, the switches SWA, SWB, SWC, SWD to be pressed are different in each unit 121b, 122b, 123b, 124b. Since each unit 121b, 122b, 123b, 124b receives a voltage signal from a different switch, the terminal ID can be automatically set using this as a value unique to each unit. In other words, if each analog input unit is configured to be able to read different status signals by being attached to the storage case, the terminal ID can be automatically set based on this.

  By providing a setting switch in the analog input unit, a unique terminal identification code (terminal ID) can be set in the analog input unit by manually operating the switch to hold (fix) the state. .

(2-2-2) Calibration Value of Analog Input Unit Next, the calibration value of the analog input unit 121 will be described.
Calibration values for the analog input section (calibration values for correcting gains and phase shifts between analog channels due to errors in auxiliary current transformers, transformers for auxiliary instruments, group delay time of high frequency rejection filters, circuit errors, etc.) The calibration value (d3) is taken out from the stored storage unit 121c and added to the electric quantity data AD1. The calibration value added to the electric quantity data AD1 is used by the arithmetic unit 11 for correcting electric quantity data.

  Note that the calibration value can be stored from the outside (for example, the arithmetic unit 11, test equipment, personal computer terminal, etc.) using the serial signal SD1211 and serially via the digital transmission input / output control unit 121D. / Taken into parallel conversion unit 121B (d4). The serial / parallel converter 121B converts the serial data into a parallel value, and stores the calibration value data in the calibration value storage unit 121C.

  The combination of the configuration in which the calibration value is stored from the outside and the configuration in which the stored calibration value is added to the electric quantity data AD1 is an external test facility or arithmetic unit 11 to which the electric quantity data AD21 to which the calibration value is added is input. It can also be used for the purpose of confirming whether the calibration value is the same as that stored in a terminal such as a personal computer. In this way, the calibration value can be confirmed from the arithmetic unit, the external tester, or the monitor terminal by the configuration in which the analog input unit can write and read the calibration value.

(2-2-3) Sampling control unit 1216
Next, the sampling control unit 1216 will be described.
The digital transmission input / output control unit 121D in the analog input unit 121 transmits and receives data in accordance with the transmission protocol of the serial buses S121 to S12n. In this case, the sampling control unit 1216 outputs a signal SPA different from the serial data SD1211. Input from a bus switch 141 described later. This signal SPA is a sampling reference signal. The sampling control unit 1216 generates a holding signal SP1 for the sample and hold circuits 1213a to 1213d, a switch switching signal SP2 in the multiplexer 1214, and a conversion control signal SP3 to the analog / digital conversion unit 1215 from the sampling reference signal SPA.

  The sampling reference signal SPA is a pulse signal that can generate a timing signal such as an electrical angle of 3.75 ° or an electrical angle of 7.5 °, or an electrical angle of 15 ° or an electrical angle of 30 °. The pulse signal SPA and the timing signals SP1, SP2, and SP3 are synchronized. The present embodiment can also be applied to high-speed sampling with an electrical angle smaller than 3.75 °. In high-speed sampling, when the data amount increases and the serial transmission load becomes heavy, the digital data after analog / digital conversion may be subjected to averaging processing or the like to reduce the data amount. In FIG. 11, the digital transmission input / output control unit 121D outputs the sampling reference signal SPB to the sampling control unit 1216, but this shows the case of a modified example to be described later. It is not necessary when SPA is entered.

(2-2-4) Modified Example of Sampling Reference Signal Generation FIG. 17 shows the analog input unit 121 when the digital transmission input / output control unit 121D outputs the sampling reference signal SPB to the sampling control unit 1216. ˜12n and the serial transmission system between the main relay arithmetic unit 111 (the bus switch and the like are not shown) S121 to S12n and S141a.

  In the above-described embodiment, the configuration in which the sampling reference signal SPA is distinguished from the serial transmission system and distributed from the bus switch 141 to the analog input units 121 to 12n and the arithmetic unit 11 is shown. In the modification of FIG. 17, a serial transmission system is used and transmission data frames from the main relay arithmetic unit 111 to the analog input units 121 to 12n are sequentially transmitted at the sampling period ST. The transmission data frame A and the next transmission data frame B repeat the transmission timing in the cycle ST in synchronization with the sampling cycle of the analog input. The analog input units 121 to 12n that have received this frame synchronize at the reception timing (referred to as frame reception synchronization), and generate a sampling reference signal SPB for analog input.

  As shown in FIG. 11, data frames A and B (corresponding to an arrow SD1211 in FIG. 11) are received by the digital transmission input / output control unit 121D, and a sampling reference signal SPB is generated in synchronization with frame reception, and the sampling control unit To 1216. In the case of this modification, it is not necessary to input the sampling reference signal SPA shown in FIG. 11 (even if there is an input, one of the signals SPB and SPA is selected).

  The data content W2 of the data frame A is illustrated in FIG. The data is composed of a frame header H, a sampling flag SPF, data A, and an error detection code CRC. The sampling flag SPF is effective when the data frame transmission cycle to the analog input units 121 to 12n is made earlier than the sampling cycle of the analog input. For example, when the data frame transmission cycle is four times faster than the sampling cycle of analog input, the sampling flag SPF enables the flag (set to a predetermined value, etc.) only once in four data frames. The analog input units 121 to 12n) may generate the sampling reference signal SPB for analog input in synchronization with the timing at which a valid value is detected in the flag SPF of the received data frame.

  The information terminal unit 113 receives the transmission data frame from the main relay arithmetic unit 111, synchronizes from the received frame in the same manner as the analog input unit, and internally generates a sampling reference signal as a substitute for the sampling reference signal SPA. . Alternatively, the information terminal unit 113 may be input from both the main relay arithmetic unit 111 and the accident detection arithmetic unit 112 through a dedicated signal line in the arithmetic unit.

  In FIG. 17, the bus switch 141 takes in the sampling reference signal generator 1413 when relaying the transmission data frame from the main relay arithmetic unit 111, and similarly, a synchronization signal that substitutes for the sampling reference signal SPA. And the switching control unit 1412 is controlled by the signal.

  Transmission of transmission data from the analog input units 121 to 12n to the arithmetic unit 111 and the information terminal unit 113 and the switch mechanism are the same as those described above. In FIG. 17, only the main functional components are described, but the accident detection side can be similarly implemented in a data frame transmitted from the accident detection relay arithmetic unit 112 to the analog input units 131 to 13n.

  According to the configuration of FIG. 17, in order to distribute the reference signal for sampling to the analog input unit and the bus switch function unit in the protective relay, in addition to the serial transmission system between the arithmetic unit and the analog input unit, another No transmission medium (separate signal line, cable, etc.) is required. Therefore, the cable wiring in the protective relay is simplified, and the hardware quality and maintainability are improved.

(3) Bus switches 141 and 142
Next, the bus switches 141 and 142 will be described with reference to FIG. Here, the bus switch 141 will be described as a representative. The operation of the bus switch 142 is the same. FIG. 18 illustrates only functional units necessary for the arithmetic unit 11 to acquire the electric quantity data from the analog input units 121 to 12n via the serial bus. Further, a functional part for relaying the transmission data SD1211 from the arithmetic unit 11 to the analog input units 121 to 12n is not shown.

  The bus switch 141 collects the serial cables S121 to S12n and relays serial data frames (electric quantity data) # 1 to #n output from the analog input units 121 to 12n to the main relay arithmetic unit 111 and the information terminal unit 113. . The bus switch 141 takes in serial data frames # 1 to #n and stores them in the storage buffers 14111 to 1411n. The storage buffers 14111 to 1111n are semiconductor elements such as memories (static RAM, dynamic RAM, dual port RAM, FIFO memory, etc.), circuits composed of discrete ICs having a data holding function, FPGA (Field Programmable Gate Array), PLD There are a holding circuit logically configured in a custom IC such as (Programmable Logic Device), PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Device), and ASIC, and a built-in memory. It goes without saying that any data can be stored as long as it can be stored.

  The serial data frames # 1 to #n stored in the storage buffers 14111 to 1411n are transmitted to the transmission paths OS121 to OS12n by opening / closing OF1 to OFn of the switches SW1 to SWn. Switching of the switches SW1 to SWn is controlled by a switching control unit 1412. When the switches SW1 to SWn are all in the “open” state, the switch SW1 is closed under the control of the switching control unit 1412, and the data frame # 1 stored from the storage buffer 14111 is transmitted from the transmission path OS121 to the transmission path OS13. Next, the switch SW1 is opened, the switch SW2 is closed, and transmission is performed from the transmission path OS122 to the transmission path OS13. By sequentially repeating this up to the switch SWn, transmission Fo1 can be performed as serial data via the transmission path OS13 shared by all the electrical quantity data # 1 to #n for one sampling.

  The serial data frame sequences # 1 to #n are distributed to the serial cable S141a side Fo3 and the serial cable S141b side Fo2 via the branching unit DS, and the same data # 1 to #n are simultaneously transmitted to the main relay arithmetic unit 111 and the information terminal. Input to the unit 113. A functional unit that extracts data from the storage device and outputs the data to the transmission line OS 13 at a predetermined transmission speed by a communication controller or the like is also provided, but the illustration is omitted. A method for generating the switching timing of the switching control unit 1412 will be described later.

  If the transmission paths OS121 to OS12n, OS13, branching section DS1, etc. in the bus switch 141 are printed circuit board patterns, the storage buffers 14111 to 1411n, the switching control section 1412, and a sampling reference signal generation section 1413 to be described later are provided on the printed circuit board. Can be mounted as a circuit or a semiconductor element. Furthermore, at least a part of the configuration of all the components and the transmission path in the bus switch 141 is a logic circuit in the FPGA, PLD, PAL, GAL, CPLD, ASIC (transmission path is logical wiring, switch is an electronic switch) As a result, the printed circuit board can be reduced in size. It goes without saying that it is possible to incorporate all the configuration requirements and the transmission path as a logic circuit into one element (IC chip) of the bus switch function.

  By the way, it is possible to automatically set the terminal ID by configuring the case in which the analog input unit is accommodated as described above so that an electrical and mechanical unique state signal can be acquired. When the analog input unit has a unique terminal ID, the arithmetic unit adds the terminal ID value as information to the electric quantity data frame distributed to the arithmetic unit, so that the arithmetic unit can obtain the terminal ID from the received electric quantity data frame. Can be read. As a result, even if the serial cable of the analog input unit is connected to an arbitrary input port of the bus switch and the reception order of the data frames changes, a connection error can be detected by looking at the terminal ID.

  This will be described with reference to FIGS. In the configuration of the bus switch 141 in FIG. 18, the order (position) of data received by the arithmetic unit side is fixed by the port connected to the serial cable of the analog input unit. FIG. 19 shows a case where the serial cable connection between the analog input unit 121 and the analog input unit 122 is switched with respect to FIG. In this case, the frame # 1 and the frame # 2 are also switched in the order of frames organized by the transmission path OS13 in the bus switch 141. If the serial cable connection port of the bus switch is incorrect as shown in FIG. 19, the arithmetic unit side identifies the received data frame in order, so that the data of frame # 2 is erroneously determined as the data of the analog input unit 121. . When the terminal ID is included in the data content W1 of the frame # 2, the arithmetic unit does not mistake the data transmission source terminal. As a result, it is possible to detect a connection error to the bus switch and issue an alarm.

  It is also possible to add sampling address values to the electric quantity data frames # 1 to #n distributed from the analog input unit. The sampling address value is an order counter value (may be a time stamp) provided for each sampling of analog input data. Thereby, the arithmetic unit can determine whether or not the electric quantity data to be received can be acquired in the sampling order for each sampling by checking the sampling address. It is possible to detect a loss of data received at every sampling due to some defect in hardware or the like. This is because the configuration that is detected by the bus switch inserts a code string (dummy data frame) indicating missing information into the missing data frame and distributes it to the computing unit. Can do.

(4) Transmission System Next, a transmission system from the main relay arithmetic unit 111 to the analog input units 121 to 12n will be described with reference to FIG. In FIG. 20, the configuration of the bus switch 141 shown in FIG. 18 is not shown. From the main relay arithmetic unit 111, data is broadcasted via the transmission path S141a, the transmission path OS14 in the bus switch 141, and branched from the transmission path S121, S122 to S12n. The data to be transmitted is data such as the calibration value described above. In order to broadcast the data, a destination identification code (terminal ID value) is added to the data so that the corresponding analog input unit can identify and capture the data.

(5) Sampling reference signal generator 1413
Next, the sampling reference signal generator 1413 in the bus switch 141 will be described.
The sampling reference signal generator 1413 generates the above-described sampling reference signal SPA. This signal SPA is output to the switching control unit 1412 and distributed to the analog input units 121 to 12n, the main relay arithmetic unit 111, and the information terminal unit 113. The sampling reference signal SPA is based on the reference clock of the transmitter in the sampling reference signal generator 1413, or is not shown in FIG. 18, but is a sampling master common to substations outside the protective relay 1a. For example, a reference time signal (1-second pulse signal) from a GPS satellite may be used as the reference clock.

  An example in which the sampling reference signal SPA is input and the switching control unit 1412 generates switching control timing is shown in FIG. In FIG. 21, the sampling reference signal SPA is a pulse signal, and the time interval between the timing ts0 and the timing ts1 when the signal falls to the “L” level is a sampling period.

  The switching control unit 1412 includes an internal counter (or timer), and sequentially updates the counter value CN from 1 to N times at a predetermined cycle at timing ts0, and controls the switch SW1 at timing ts01 that reaches N times. After that, the counter value CN is reset to “0”, and the counter value CN is similarly updated up to N times at the next timing ts1, and the switch SW1 is controlled at the timing ts11. Similarly, the switches SW2 to SWn are controlled. The switches SW1 to SWn) are controlled at the timing when the counter value CN is updated N times, but the timings at which all the switches SW1 to SWn are “closed” are controlled while being shifted in time. That is, each of the switches SW1 to SWn is controlled by a different “N value” of the counter value CN.

How to determine the “N value” will be described.
Data frames # 1 to #n shown in FIG. 18 all have the same format and the same frame length (bit string). In order to transmit the data frames # 1 to #n from the storage buffers 14111 to 1411n sequentially to the shared transmission line OS13 without data collision, it is necessary to transmit another data frame until transmission of one data frame is completed by the switch “closed”. The bus switch must remain “open”.

  The transmission completion time of this one data frame determines the minimum switch switching period (the minimum value of the “N value” for each switch). Further, in the main relay arithmetic unit 111 or the accident detection relay arithmetic unit 112, the maximum switch switching period (the above-mentioned for each switch) depends on how far reception delay is allowed for all data frames # 1 to #n for one sampling. The maximum value of “N value” is determined.

A significant reception delay deteriorates the operability of the protection relay. The reception delay varies depending on the protection relay model, but has an allowable range. The backup protective relay (ie, back-up protection) outputs a trip command to the protection target switch as a backup when the main protective protective relay does not work in the event of an accident. Such a protective relay may be slower in relay operation than the main protection. An example formula for determining the “N value” of the counter value CN of each switch SW1 to SWn is shown below.

However, each character in the formula (1) has the following meaning.
β = 1 data frame length / transmission speed 1 data frame length: total data length for one sampling with respect to all input electric quantities of the analog input unit N (1): “N value” of the counter value CN for the switch SW1
N (k): “N value” of the counter value CN for the switch SWk, where k = 2 to n
N (n): “N value” of the counter value CN for the switch SWn
α: Analog-digital conversion time required for all data of one data frame length in the analog input unit. It should be noted that the data may be ignored when the data is transmitted within the analog input unit with a shift of one sampling or more.
TCN: Update cycle of the counter value CN Tmax: Allowable time from the sampling of the input electric quantity to the completion of reception by the arithmetic unit 11

In the equation (1), N (k) −N (k−1) represents a switching interval between the switches SW1 to SWn by a counter value CN, and is switched when this is multiplied by an update cycle of the counter value CN. Time is expressed by the following equation (2).

  When the analog / digital conversion output is a serial output, there is a method of transmitting the serial output to the bus switch 141 in synchronization with the timing of the conversion output. In this case, the reception of the bus switch 141 to the storage buffer is completed simultaneously with the completion of the analog / digital conversion output, so the first expression (N (1)) of the expression (1) and the first expression (switch of the expression (2)) Only SW1 switching time) may be regarded as β = 0.

  In the expressions (1) and (2), β in the first expression and β in the second expression may be different. This means that the transmission speed of serial data from the analog input unit to the bus switch 141 and the transmission speed from the bus switch 141 to the arithmetic unit 11 may be different. For example, the analog input unit to the bus switch 141 are transmitted at 10 Mbps, and the speed between the bus switch 141 and the arithmetic unit 11 is 100 Mbps and transmitted. This is because the serial bus has a larger transmission load after the concentration than the transmission load of each transmission path before the concentration.

  Further, the above-described methods are all synchronized with the sampling reference signal SPA (that is, synchronized with sampling of the analog input), but synchronized with the reception timing of the sampling data received by the bus switch 141 from the specific analog input unit. Then, a synchronization signal equivalent to the sampling reference signal SPA may be generated and substituted. In this case, since the switching time of the switch SW1 is determined by this reception timing, only the second and third expressions of the expressions (1) and (2) are applied. Since this method is also based on the sampling timing of sampling data synchronized with sampling, the basic idea is to directly capture the sampling reference signal SPA from the outside (the switch control timing is generated in synchronization with the sampling of the analog input). Is the same).

(6) Acquisition of Input Electric Quantity of Arithmetic Unit 11 Next, an aspect in which the arithmetic unit 11 acquires the input electric quantity when the allowable time Tmax = one sampling period of analog input will be described with reference to FIG. FIG. 22 illustrates analog input units 121 to 12n as an example. In the figure, each analog input unit acts as in (1) to (n). Note that the three channels input by each analog input unit are examples for explanation, and the number of channels is not limited.
(1) The analog input unit 121 inputs analog electric quantities AF11, AF12, AF13 for three channels.
(2) The analog input unit 122 inputs analog electric quantities AF21, AF22, AF23 for three channels.
(n) The analog input unit 12n inputs analog electric quantities AFn1, AFn2, and AFn3 for three channels.

  Each analog input unit samples an analog electric quantity at the same sampling period ST and outputs it as digital data. The figure shows the aspect W until the reception is completed within one sampling period. In the analog input units 121 to 12n, sampling is synchronized, and the electric quantity is sampled at the same sampling timing tp0.

  The data # 11 to # 13, # 21 to # 23,... # N1 to # n3, which are one sampling data, are input to the bus switch 141 as parallel data frames. In the bus switch 141, the data frames transmitted in parallel are organized (PS) as one data frame sequence (serial data). The arithmetic unit 11 receives all data by timing tp1 after one sampling.

  Next, FIG. 23 shows the timing of the relay calculation when the allowable time Tmax = one sampling period of analog input. FIG. 23 exemplifies the timing at which the arithmetic unit 11 receives the sampling data of the analog electric quantity as X1 to X8, Y1 to Y8, and Z1 to Z8. The protection relay calculation cycle is indicated by SSP1, SSP2, and SSP3.

  For example, if the protection relay calculation cycle is 30 ° electrical angle, the sampling cycle is 3.75 ° electrical angle in FIG. All the electric quantity data sampled in the current relay calculation cycle SSP1 is received by the calculation unit 11 within an electrical angle of 30 °. Based on the received electric quantity data, the relay calculation is performed at the next electric angle of 30 ° (SSP2). Thereby, accident determination can be performed at the next electrical angle of 30 ° based on the data acquired at the electrical angle of 30 °. If the time is allowed after the reception timing X8 within the period SSP1, the relay calculation may be performed without waiting for the next electrical angle of 30 °. In addition, in the relay calculation, since the effective value, phase, and the like are calculated from the instantaneous value of the electric quantity, it goes without saying that the relay calculation is also performed using data acquired in the past electrical angle.

Even if there is some transmission delay, it is possible to perform the relay operation as in the case described above. This point will be described with reference to FIG.
Also in FIG. 24, the protection relay calculation cycle (SSP1, SSP2, SSP3) is described as an electrical angle of 30 °, and the sampling cycle is described as an electrical angle of 3.75 °. When reception timings X1 to X8 of the electric quantity sampled within the current electrical angle 30 ° (SSP1) cannot be received without waiting until the next electrical angle 30 ° (SSP2) due to transmission delay (reception timing X7, X8 data), if the reception timings X7 and X8 are within the relay calculation cycle SSP2, these data are combined with the data received within the previous electrical angle 30 ° (SSP1) (data of the reception timings X1 to X6). Based on the above, it is possible to perform a relay operation within the period SSP2. In this case, the same effect as that described with reference to FIG. 24 is obtained.

  As described above, the transmission delay can be tolerated, but since the relay operation is performed after the reception timing X8, the remaining time of the cycle SSP2 becomes important. If the reception timing X8 is greatly delayed, the time available for the calculation within the period SSP2 is reduced by that amount, which may lead to the calculation time being over. In addition, there may be a case where the reception timing X8 is significantly delayed such as after the period SSP3.

  In this case, both the former and the latter use the acquired data before the electrical angle 60 ° and the electrical angle 90, not the electrical quantity sampled by the analog input unit at the previous electrical angle 30 °, and the electrical angle 30 The relay calculation may be performed every °. For example, when using sampling data before an electrical angle of 60 °, the relay operation time is generally delayed by an electrical angle of 30 ° compared to the case where acquired data before an electrical angle of 30 ° can be used. Such a method can be applied as long as the performance of the protective relay is acceptable. The allowable time Tmax for transmission and reception may be determined according to the required performance of the protective relay.

  Although the relay calculation cycle has been described with an electrical angle of 30 ° and the sampling cycle with an electrical angle of 3.75 °, this does not limit the use of this embodiment. The relay calculation cycle is an arbitrary electrical angle, and a cycle equal to or less than that is very good as the sampling cycle. For example, if the sampling period and the relay calculation period are both set to an electrical angle of 30 ° and the reception timing in the relay calculation cycle SSP1 in FIG. 23 is X1 (X2 to X8 are not present), the process waits until the next cycle SSP2 of an electrical angle of 30 °. Even if not, the relay calculation may be performed using the reception data of the X1 timing within the period SSP1.

23 and 24 are examples in which the electric quantity data is acquired at every sampling, but a method of transmitting several samplings at a time may be used. This is shown in FIG. 25 and FIG.
In this figure, for example, assuming that the relay calculation cycle is 30 ° electrical angle and the sampling cycle is 3.75 ° electrical sampling, the data corresponding to 4 samplings of electrical angle 3.75 ° are timings X11, X12, Y11, Y12. , Z11, Z12 are received by the arithmetic unit 11. In FIG. 25, all the electric quantities sampled within one relay calculation cycle are received as in FIG. 23, and in FIG. 26, reception of four sampling data for an electrical angle of 15 ° is completed in the next relay calculation cycle. To do. The timing and effect of the relay calculation for the received data are the same as FIG. 23 for FIG. 25 and FIG. 26 for FIG.

  The frequency of the sampling reference signal SPA described so far may be an analog input sampling frequency, but is not limited thereto. The sampling reference signal SPA may be different from the sampling frequency of the analog input. The reason for distributing the sampling reference signal SPA to each component in the protection relay is to treat the sampling reference signal SPA as a reference synchronization signal. Used to synchronize each component. If the sampling reference signal SPA is different from the sampling frequency of the analog input, it is only necessary to synchronize with the signal SPA and generate a signal having a required frequency in each component.

  The main analog input units 1121 to 12n and the main relay arithmetic unit 111 have been described above as a representative. However, the relationship between the accident detection analog input units 131 to 13n) and the accident detection relay arithmetic unit 112 is the same. Note that the sampling reference signal may be shared between the main side and the accident detection side, or may be provided individually.

  The effect of sharing is synchronized even when analog inputs on both the main side and the accident detection side are required, so that the information terminal unit 113 can reliably acquire data. In this case, a dedicated bus switch is provided in the information terminal unit 113, a 1-to-N transmission star topology is used between the information terminal unit and the analog input unit, and an analog input unit is output on the main side and the accident detection side. It is possible to adopt a configuration with two ports and a one-to-one topology.

  Moreover, the effect when not sharing is a failure of the shared part (sampling reference signal generating part, etc.), and both the main and the accident detection are not affected. This is effective in ensuring the independence of main and accident detection.

(7) Input / output unit 15
Finally, the input / output unit 15, which is a component of the protective relay 1a, will be described with reference to FIGS. 27 includes a main input / output unit 151 and an accident detection input / output unit 152, both of which are independent of each other. The purpose is to ensure the independence of main and accident detection.

  The main input / output unit 151 inputs a contact output command from the main relay calculation unit 111 via the transmission medium IO1, controls the output contact 1511 provided in its own unit, and issues a control command DO11. Also, the main input / output unit 151 performs insulation input of the external device information DI11 and outputs the external device information to the main relay arithmetic unit 111 via the transmission medium IO1. The accident detection input / output unit 152 receives a contact output command from the accident detection relay arithmetic unit 112 via the transmission medium IO2, controls the output contact 1521 provided in its own unit, and issues a control command DO12.

  In addition, the accident detection input / output unit 152 insulates the external device information DI12 and outputs the external device information to the accident detection relay arithmetic unit 112 via the transmission medium IO2. The transmission media IO1 and IO2 can be applied to either serial transmission media or parallel transmission media. The feature of the figure is that the main relay calculation result (control command) and the accident detection relay calculation (control command) are individually output from the input / output unit 15. The AND configuration (trip circuit) of both outputs is implemented in a device incorporating a protective relay.

  The input / output unit 15b of FIG. 28 includes this trip circuit as a configuration PO in the input / output unit. In this case, the external DC 110V power supply bus P110 and the output contacts 1511 and 1512 are connected by an AND circuit. Aggregated control output DO1 is output.

  The main input / output unit 151 and the accident detection input / output unit 152 shown in FIGS. 27 and 28 may be separated into physically independent units. In addition, the input / output unit 15 may have only an output unit that does not include an input unit. In this case, the input / output unit 15 is an output unit.

(8) Modified Example of Bus Switch and Analog Input Unit A modified example in which the functions of the bus switch shown in FIG. 18 are distributed to the analog input unit side will be described. This is shown in FIG. 29 (illustration of components that are not necessary for description is omitted). In addition, although the bus switch and the analog input unit on the main side will be described as an example, the accident detection side can be similarly applied.

  In FIG. 29, the storage buffers 14111 to 1111n and the switch units SW1 to SWn, which are the main functions of the bus switch 141, are provided in the analog input units 121 to 12n, and the bus switch 141 is provided only with the function of concentrating and distributing the sampling reference signal. ing. In the analog input units 121 to 12n in the figure, storage buffers 14111 to 1411n and switches SW1 to SWn are functionally connected to the A / D converters 1215 to 12n5 in a one-to-one manner.

  Note that the switching control unit 1412 in the bus switch 141 in FIG. 18 is naturally provided in each of the analog input units 121 to 12n. The switching control unit 1412 in FIG. 3 controls all the bus switches SW1 to SWn in the bus switch 141. However, the “switching control unit 1412 in the analog input unit” (not shown) in FIG. SW1 or SW2 or... SWn) is controlled. In this case, the switches SW1 to SWn in the analog input units 121 to 12n are controlled with different switching times.

  Further, this control timing is the switch SW1 or SW2 corresponding to the analog input units 121 to 12n corresponding to the “N value” of the counter value CN determined by the expression (1) described in the operation of the first embodiment, or SWn. The switching time determined by equation (2) may be used. However, in this modification, the storage buffers 14111 to 1411n are located in front of the serial bus transmission systems S121 to S12n shown in FIG. In this case, only the first expression of the expressions (1) and (2) is not affected by the bus transmission time, and may be regarded as β = 0. In this modification, only this point is different, and all the switching control methods described based on FIG. 18 can be applied to this modification.

  Thus, the setting of the “N value” of the counter value CN or a parameter (switching time or the like) corresponding to the counter value CN may be provided in each analog input unit, for example. This setting unit may be provided with a mechanical switch or the like in the analog input unit so that it can be set by operating the switch. The terminal ID setting method can be applied to the setting of the “N value” of the counter value CN or a parameter corresponding thereto in the present modification.

  Even if the storage devices 14111 to 1411n and the switches SW1 to SWn are provided in each analog input unit as shown in FIG. 29, the operation in combination with the concentrator of the bus switch (no switch function) shown in FIG. Since the operation is the same as that described above, the description thereof is omitted. Needless to say, it has the same effect.

  An effect peculiar to this modification is to simplify the bus switch 141 (no switch function), and as a result, it can be easily incorporated in the main relay arithmetic unit 111 as shown in FIG. The built-in bus switch 141 (without a switch function) can be connected to the internal circuit 1111 of the main relay arithmetic unit 111 via the signal medium IS1. The information terminal unit 113 is configured to acquire the amount of electricity through the signal medium IS2 with the main relay arithmetic unit 111. This can be similarly implemented in the relationship between the bus switch 142 (no switch function), the accident detection relay arithmetic unit 112, and the information terminal unit 113. Needless to say, the bus switch 141 (with switch function) of FIG.

(9) Effects of each unit of the present embodiment As described above, according to the present embodiment, in the protection relay that includes a plurality of analog input units that are sampling-synchronized and that allows the arithmetic unit to acquire the amount of electricity by serial transmission, The bus switch synchronizes with the sampling and controls the switch without data collision so that the arithmetic unit can acquire the electric quantity within a predetermined time allowable as performance. As a result, in a star topology in which the transmission system is concentrated, the arithmetic unit can acquire the amount of electricity efficiently and safely and reliably, and the relay performance can be ensured.

  In addition, the switch control of the bus switch applies the formula (1) or (2) described for the sampling reference signal generation unit to the transmission time, the data frame length of the electrical quantity, and the predetermined time allowable as the relay performance, The control conditions of the bus switch can be determined and can be applied according to the required specifications of the relay performance of the protective relay.

  In particular, in a serial transmission system, there is a conventional switching hub as a means for concentrating buses and relaying without data collision. The switching hub has a plurality of input / output ports, and has a switch function that identifies the destination (code) of the relayed data frame and outputs the data frame only to the output port where the destination (transmission destination) terminal is located. It operates with its own switch switching timing and delay time in the first-come-first-served order without synchronizing with external equipment. The bus switch of this embodiment does not require the destination (code) of the data frame, distributes all input data to the output side, and performs switch control in synchronization with sampling of the analog input of the protection relay. The switching hub and the bus switch of the present embodiment are different in the switch control method as an operation, and there is a difference as to whether or not the time required for acquiring the amount of electricity necessary as a protective relay can be guaranteed. As a matter of course, it is difficult to operate independently such as a switching hub, but in the bus switch of this embodiment, a time guarantee for obtaining the amount of electricity necessary as a protective relay (switch to meet the relay performance requirements) It is possible to realize control).

  In the protective relay, all analog inputs are sampling-synchronized (group delay time of the analog filter section and switching time at the multiplexer generated when there is no sample hold circuit) to ensure relay accuracy (operation level, operation sensitivity, etc.) For example, the sampling electric quantity is distributed simultaneously from a plurality of analog input units. When this is relayed by the switching hub, it is transmitted to the arithmetic unit on a first-come-first-served basis, and therefore the order in which the arithmetic unit receives the electrical quantity data frame is indefinite every time.

  In this case, in order for the relay operation unit to correctly perform the relay operation, it is necessary to identify from which analog input unit the received data is transmitted, and this identification process (received and stored in the storage unit or the like of the operation unit). Since the extra processing such as searching the data and the data necessary for the computation cannot be taken out immediately, extra processing such as rearranging as necessary is required, and the number of analog input units increases. This burden of identification processing also increases. This requires time for the identification processing within the relay calculation cycle, and the original relay calculation time cannot be secured, resulting in problems such as calculation time over.

  However, by applying the bus switch in the present embodiment, the order of the electrical quantity data frames received by the arithmetic unit is fixed, so that the extra identification process as described above is not necessary. Therefore, even in the protective relay that requires a plurality of analog input units, the relay calculation time can be ensured.

1 is a functional block diagram showing a first embodiment of a digital protection relay of the present invention. The functional block diagram which shows the example of the 1 to 1 type | mold topology in the conventional digital type protective relay. The functional block diagram which shows the structural example by the transmission topology in 1st Embodiment of this invention. The functional block diagram which shows 2nd Embodiment of this invention. The functional block diagram which shows the modification of 2nd Embodiment of this invention. The functional block diagram which shows 3rd Embodiment of this invention. The functional block diagram of the protection relay which is 4th Embodiment of this invention, Comprising: The serial transmission cable between an accident detection relay arithmetic unit and an analog input unit is sufficient. It is 5th Embodiment of this invention, Comprising: The functional block diagram of the protective relay which duplicated the arithmetic unit. The functional block diagram which is 6th Embodiment of this invention and shows the digital type protective relay which uses a multidrop type | mold topology. FIG. 14 is a functional block diagram of a protective relay that is a seventh embodiment of the present invention and combines a star topology and a multidrop topology. The functional block diagram which shows the analog input unit in embodiment of this invention. FIG. 3 is a layout diagram of a sample and hold circuit in an analog input unit according to the present invention. The functional block diagram which shows the 1st structural example for terminal ID automatic identification in embodiment of this invention. The functional block diagram which shows the 1st structural example of the analog input unit applicable part for terminal ID automatic identification in embodiment of this invention. The functional block diagram which shows the 2nd structural example for terminal ID automatic identification in embodiment of this invention. The functional block diagram which shows the 2nd structural example of the analog input unit applicable site | part for terminal ID automatic identification in embodiment of this invention. The schematic diagram which shows the state of the frame reception synchronization in embodiment of this invention. The functional block diagram which shows the bus switch in embodiment of this invention. The functional block diagram which shows the bus switch from which the connection port in embodiment of this invention differs. The block diagram which shows the transmission system of transmission to the analog input unit from the arithmetic unit in embodiment of this invention. The schematic diagram which shows the effect | action of the bus switch switching based on the reference signal for sampling in embodiment of this invention. The schematic diagram which shows the effect | action from the sampling of the analog quantity in the embodiment of this invention to the completion of reception of an arithmetic unit. The schematic diagram which shows the 1st timing example of A / D data reception and relay calculation in embodiment of this invention. The schematic diagram which shows the 2nd timing example of A / D data reception and relay calculation in embodiment of this invention. The schematic diagram which shows the 3rd timing example of A / D data reception and relay calculation in embodiment of this invention. The schematic diagram which shows the 4th timing example of A / D data reception and relay calculation in embodiment of this invention. The functional block diagram which shows the 1st structural example of the input-output unit in embodiment of this invention. The functional block diagram which shows the 2nd structural example of the input-output unit in embodiment of this invention. The functional block diagram which shows the structural example at the time of disperse | distributing a bus switch function to an analog input unit in embodiment of this invention. The functional block diagram which shows the structural example at the time of providing the switching function of a bus switch in the analog input unit in embodiment of this invention.

Explanation of symbols

1a: digital type protective relay 11: arithmetic unit 111: main relay arithmetic unit 112: accident detection relay arithmetic unit 113: information terminal units 121, 122,... 12n: analog input units 131, 132,. Analog input units 141 and 142 for detection relays: Bus switch 15: Input / output units AI21, AI22,... AI2n: Analog electric quantities AI31, AI32,. Electricity input IO1: Connection cable between main relay arithmetic unit and input / output unit IO2: Connection cable between accident detection relay arithmetic unit and input / output unit S121, S122,... S12n: Analog input unit Serial transmission cables S131, S132,... S13n between the analog input units 131 to 13n and the arithmetic unit S141a, S141b: Serial transmission cables between the bus switch 141 and the arithmetic unit 11 S142a, S142b: Serial transmission cable between the bus switch 142 and the arithmetic unit 11

Claims (15)

In the digital protection relay that performs protection relay calculation based on the sampling data obtained by converting the analog electricity quantity of the electrical equipment to be protected into a digital value, and outputs the result of the protection relay calculation,
A plurality of analog input means for sampling the analog electric quantity based on a sampling reference signal and outputting sampling data converted into a digital value, and an arithmetic means for performing at least the protection relay calculation,
The sampling data transmission system from the plurality of analog input means to the arithmetic means is constituted by a serial bus having a shared part at least in part,
The sampling data is sent to the common unit for each analog input unit so that serial transmission of each sampling data in the plurality of analog input units is received by the arithmetic unit within a predetermined time without data collision in the common unit. A switch to be introduced to the bus, and to switch the switch for each analog input means in synchronization with the reference signal for sampling and to control the switch to complete the switching of all the switches within the cycle of the protection relay calculation A digital protective relay characterized by comprising:   2. The digital protection relay according to claim 1, wherein a sampling data transmission system between the arithmetic means and the plurality of analog input means is configured in a star type or multidrop type topology of 1 to N transmission. The calculation means is composed of main relay calculation means and accident detection relay calculation means,
The analog input means comprises an analog input means for main relay and an analog input means for accident detection means,
A sampling data transmission system between the main relay computing means and the plurality of main relay analog input means is configured in a star-type or multi-drop type topology of 1: N transmission,
2. The sampling data transmission system between the accident detection relay computing means and a plurality of accident detection means analog input means is configured in a star topology or multidrop type of 1: N transmission. Digital type protective relay. An information terminal means for executing an oscilloscope function or a terminal function of a failure point rating device or an interface function with an external portable setting terminal,
A sampling data transmission system between the information terminal means and the plurality of main relay analog input means is configured in a star topology of 1 to N transmission,
4. A digital protection relay according to claim 3 , wherein a sampling data transmission system between said information terminal means and said plurality of accident detection means analog input means is configured in a star topology of 1: N transmission. . The calculation means is composed of main relay calculation means and accident detection relay calculation means,
The analog input means comprises an analog input means for main relay and an analog input means for accident detection means,
A sampling data transmission system between the main relay computing means and the plurality of main relay analog input means is configured in a star topology of 1 to N transmission,
2. The digital protective relay according to claim 1, wherein a sampling data transmission system between the accident detection relay calculation means and the analog input means for accident detection means is configured in a one-to-one topology.   2. The digital type protective relay according to claim 1, wherein a sampling data transmission system between the arithmetic means and the plurality of analog input means is constituted by a multi-drop topology and a star configuration topology of 1 to N transmission. .   2. The digital according to claim 1, further comprising a first calculation unit and a second calculation unit, wherein the first calculation unit and the second calculation unit share the plurality of analog input units. Protective relay.   The digital data according to claim 1, wherein each sampling data received from the plurality of analog input means via a serial bus is received by the arithmetic means in a fixed order by the bus switch control. Protective relay.   2. The digital protective relay according to claim 1, further comprising bus switch means having the bus switch function and having a common unit for concentrating the serial bus. The bus switch means generates a reference signal for sampling, generates a control timing of the switch based on the reference signal for sampling, and distributes the reference signal for sampling to at least the plurality of analog input units,
10. The digital protection relay according to claim 9, wherein the plurality of analog input units generate a predetermined sampling timing based on the input sampling reference signal and perform sampling of the analog electric quantity.   2. The digital protective relay according to claim 1, wherein the bus switch function is provided in the arithmetic means.   2. The digital protective relay according to claim 1, wherein the bus switch function is distributed in the plurality of analog input means.   2. The digital protective relay according to claim 1, wherein each of the plurality of analog input means includes identification information for specifying its own means.   The analog input unit includes calibration value information for an analog unit, and the calibration value information is written and read from the calculation unit or an external terminal. The calibration value information is input from the calculation unit or the external terminal. The digital protection relay according to claim 1, wherein the soundness of the digital protection relay can be confirmed.   2. The digital protective relay according to claim 1, wherein the sampling reference signal is distributed to the plurality of analog input means through a transmission medium different from the serial bus.

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