JPH0458255B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention provides information on various types of information necessary for controlling power equipment (among these, basic information is instantaneous value information of current and voltage, It is related to the protection, adjustment, and control of power systems consisting of equipment such as power plants, substations, and power transmission lines, based on the open/close status display of disconnectors, etc.).

[Background of the invention]

In existing power system control systems, the equipment used for protection and control is housed in a building called a unit room, such as in a substation, and the introduction of system voltage and current information for these devices is carried out using a field-installed CT. , a method has been used to derive the secondary output from PT through wiring. In addition, trip commands to circuit breakers, etc., which are the output of protection devices and control devices, are
The signal is supplied via the same wiring from each device in the unit room to the relevant disconnector at the site. Since each of these wiring lines is used separately for each system protection and control device, the total number of lines in the entire substation is extremely large.

Therefore, if we follow the current method of installing protection devices in unit rooms as described above for power systems that will become increasingly large and complex in the future, the wiring will become even more congested. Many problems are becoming apparent, such as the ever-increasing cost of wiring, the increasing difficulty of maintenance, and the fact that there are cases where it is not possible to accommodate the expansion due to space constraints.

By the way, originally, as mentioned above, grid protection devices input instantaneous values of current and voltage from the grid via CT and PT, and give commands to circuit breakers, etc., to protect against sudden accidents that occur in the grid. It serves the purpose of detecting and abnormal phenomena, separating the normal and abnormal parts of the system, and preventing the normal parts from being affected by the abnormal parts.
This means that the protective relay system
This means that a closed-loop control system is formed by CT, PT, breaker, and protective relay device, and the protection relay is a device that always acts together with the breaker. ing.

Looking at it from another perspective, it is natural to place the protection relay system near the CT, PT, or disconnector at the substation site, rather than gathering it in a unit room. .

However, simply installing the conventional protective relay device itself on-site has the following five major problems, and cannot be immediately put into practical use.

(1) Since it is installed in a location where it is affected by strong switching surges and large currents pass through it, it is necessary to overcome the problems of surge resistance and induction noise resistance.

(2) In order for the device to perform its own functions, there is a problem with the electricity supply, which is the driving energy for the device. In order to prepare for system accidents that may occur at any time, and to constantly perform fault judgment operations based on system voltage and current according to a predetermined operating principle, it is necessary to have a constant supply of power, but with the current method,
It is necessary to run power supply wiring from the station battery at the substation to the protective relay device installed at the yard site, which poses many problems in terms of wiring and noise resistance, making it impractical.

(3) Ensure that the health of the equipment can be checked at all times to prevent malfunctions and malfunctions, and if a malfunction occurs with the equipment, it will be automatically displayed and alerted to the main building where the person on duty is located. You need to be able to do it.

(4) In order to manage the response status of the equipment, if a system accident is detected and a response is taken, this will be automatically displayed and alerted to the main building where people are present, allowing the person on duty to handle various accidents. It is necessary to take such measures.

(5) When it is necessary to change the setting, the person on duty at the main building can confirm that the setting can be carried out and that the setting has been reliably achieved, according to the setting slip, without having to go to the site. There is a need.

Of these five problems, regarding (1), if known anti-noise countermeasures are implemented at the equipment casing level, unit level, and wiring level, it will be possible to withstand even when handling IC level signals. , which has been confirmed through long-term field tests conducted over all seasons under actual systems, and can be solved by using that method.

Regarding (2), the station batteries that were conventionally installed in one corner of the unit room can be distributed and installed near each protection relay device to supply power, or each device can be equipped with a solar battery. Techniques such as methods for achieving maintenance-free battery charging can be applied.

Regarding problem (4), if we add the automatic monitoring (automatic inspection and constant monitoring) function used in current protection relays, we can at least check the health of the equipment at the installation site, but if this continues, If the on-duty staff member who is present at
This involves the inconvenience of having to go all the way to the site and refer to the inspection-related indicator lights of the protective relay device.

Among the above-mentioned problems, current technologies in various fields cannot cover them (5), (4), (including some of (3))
A distributed protection relay (Japanese Unexamined Patent Application Publication No. 15419/1986 (hereinafter referred to as a known example)) was proposed as a device that could overcome this problem. This eliminates the need to set up a unit room for installing protective relay equipment, and also eliminates the huge amount of electrical signal wiring in substation yards, resulting in an economical and highly reliable protective relay system. has been constructed. The main features of this known protective relay system are as follows.

(1) Each protective relay device shall be installed outdoors in a field yard such as a substation near the relevant shingle breaker to be controlled and the CT and PT which are the system information sensors.
(2 of the relevant CT and PT for inputting lineage information)
(2) The power supply to each protective relay device is built into the device. or the device installed nearby is powered by its own power supply. This power supply device is configured to be completely electrically isolated from other protective relay devices.

(3) Each protective relay device shall be equipped with an automatic monitoring unit. The constant monitoring of this automatic monitoring unit is similar to the existing relay system, but the automatic inspection unit has the following new functions.

It has a function to inspect each relay element of the relay device.

To generate the inspection signal, refer to the set value of the relay in sequence, apply a check signal that matches the value to the input terminal, check at least two points near the set value, one inside the protection area and one outside the protection area, Includes a step to check whether element relays are operating properly or not.

In addition to the normal manual and automatic modes for starting inspection, there is also a transfer command mode.

If a setting change occurs, an inspection of the relay device using the new setting value is automatically performed when a series of setting tasks are completed.
Check the health of the device including the validity of the set values
can.

(4) To transmit the response status of each protective relay device to system accidents, malfunction information from automatic monitoring results, etc. to the general monitoring panel installed in the main building where the on-duty staff are present, and as part of the general monitoring. In order to transfer the relay setting value given by the protection relay setting mechanism installed in It has a transmission mechanism.

(5) The above optical fiber transmission mechanism is configured as follows.

On the main building side, in order to connect the transmitter of the parent device and one child device installed in the relay device, it is shared by the child devices of all relay devices (this refers to all the relay devices in the conventional unit room unit, for example). One optical fiber transmission line is provided.

This optical fiber transmission line forms one loop, with one end connected to the transmitter of the parent device and the other end connected to the receiver of the parent device as well.

The optical fiber transmission line and each relay device are connected through an optical branching device and an optical adder provided for each relay device.

The transmitting section of the parent device compiles a signal frame consisting of a synchronization word, a group of word slots for sending command words to each slave station, and a group of word slots for transmitting relay responses, etc., which will be described later. This signal frame is sent using this method.

After receiving the synchronization word of this signal frame, the receiving section of each small device receives the signal of the corresponding command word slot section determined for itself starting from this time. Furthermore, the transmitter of each device inserts information such as the relay response status, automatic monitoring results, etc. into the word slot for transmitting the relay response, etc. determined by itself, starting from the synchronization word reception time in the receiver. Configure.

The receiving unit of the parent device detects the synchronization word of the signal frame sent via the optical fiber transmission line, and from this time, information such as relay response sent from the small device of each relay device is transmitted.
The information is configured to be received from the corresponding word slot unit for transmitting relay responses, etc., respectively.

FIG. 5 shows an example in which the publicly known invention is applied to an ultra-high voltage substation, and is an example of the case where the invention is applied to the same number of protection relays that are housed in one unit room in an existing substation. It is. In the figure, each symbol shown in the single line diagram represents the following.

B1 and B2 are high voltage side busbars, B3 and B4 are low voltage side busbars, L1 and L2 are reception transmission lines, CB1,
CB2, CB3, CB11, CB12, CB21, CB
22, CB211, CB221, CB31, CB3
2, CB311, CB321 cutter, CT1,
CT2, CT3, CT4, CT11, CT12, CT2
1, CT22, CT211, CT221, CT31,
CT32, CT311, CT321 are current transformers,
PD1, PD2 are voltage transformers, T21, T22, T
31 and T32 are transformers; 21 and 22 are power transmission line protection relay devices that protect L1 and L2, respectively; 23, 24, and 2
5, 26 are T32, T31, T22, T21 respectively
Transformer protection relay device that protects 27,
28 and 29 are collective bus protection relay devices that protect husbands B1 and B2;
This figure shows the optical fiber transmission line that connects the system monitoring panels installed in .

As shown in the figure, each of the relay devices 21 to 29 is installed in the field yard near the trip switch, disconnector, and system information sensor CT and PT of the equipment that they are protecting. The relay devices 21 to 29 in FIG. 5 have a common standard circuit configuration except for the relay functions (the built-in automatic monitoring function also has inspection and regular monitoring functions suitable for the relay). ing. A specific example is each protection relay device 2.
FIG. 2 clearly shows the connecting portion between the optical fiber transmission line FB1, which is a communication path between the main building 1 and the optical fiber transmission line FB1. In FIG. 2, only protective relay devices 21 and 29 are clearly shown to avoid complication of the drawing.

Among the symbols in this diagram, 1, FB1, 2
1 and 29 are the same as those shown in FIG. 5, and the other symbols are as follows.

Reference numeral 11 indicates a relay setting mechanism among the parent devices attached to the monitoring panel installed in the main building 1, and from here on, all elements of all the protection relay devices 21 to 29 connected to the optical fiber transmission line FB1 are shown. Setting of the relay can be performed by selective setting operation. Although the details of the relay setting mechanism are not shown in the drawings, three mechanisms are selected and set: a mechanism for selecting a protective relay device whose setting is desired to be changed, a mechanism for similarly selecting a relay element, and a mechanism for setting a setting value. It is equipped with a setting change command mechanism that functions effectively when specified during a certain period, and a setting end command mechanism for instructing the completion of a series of setting changes. The system is configured to convey information point by point. The transmitter 13 always sends signals in the transmission signal format shown in FIG.
When the command and setting contents are transmitted from the relay setting mechanism 11, the command word slot (S#1 to S#1) in the format is sent to FB1.
#9) and sends it out. That is, among the command word slots corresponding to the protection relay to be set, C#1 contains the number corresponding to the selected relay element, C#2 contains the set value, and C#3 contains the setting change command. Insert the output of the mechanism, and insert the output of the settling end command mechanism into C#4. Of course, the non-selected command word slots have these selectively distinguishable empty signals inserted.

Since the transmission signal format shown in Fig. 3 is transmitted using a time-division cyclic transmission method, it is not possible to insert and transmit the signal set in the command word slot as is while the above settings are continued. Needless to say.

Now, returning to FIG. 2, the transmission format sent from the transmitter 13 in this way passes through the optical fiber transmission line FB1 and is transmitted to each relay device. ~291
Since the receivers 213 to 29 are equipped with
This leads to 3. This receiving section 213-293
The device includes a photoelectric conversion unit that restores the guided optical signal to an electrical signal, a synchronization signal detection unit, and a command word decoding unit.

The transmission signal format sent from the optical transmitter 13 in this way is transmitted to each relay device 21-29 through the optical fiber FB1, but each relay device 21-29 has an optical branching device 211-219. Since the receivers 213 to 293 are equipped with
This is now guided by (Figure 2).

Although not shown, the receiving units 213 to 219 of the child devices are equipped with a photoelectric conversion unit that restores the guided optical signal to an electrical signal, a synchronization word detection unit, and a command word decoding unit. Therefore, refer to the corresponding command word slot and read C#1 to C.
If there is transmission information in #4, it is given to the protection relay units 215 to 295 according to the result, stored in internal registers, etc., and made to change the setting (at this time, of course, a function to lock the relay function is added) ).

If a setting change command is issued, and after all the setting values for some relay elements are stored in the internal register group according to the predetermined correspondence, the setting end command is issued to C#4.
, the automatic monitoring unit 216
~296. As a result of this transmission, the automatic inspection functions of the automatic monitoring units 216 to 296 are activated, so that an inspection number referring to the above-mentioned new set value is issued.

Now, assuming that 21 is a back-up protection relay device for a power transmission line, an inspection method in the known invention will be described with reference to FIG.

That is, in the case of an example in which the relay element is composed of a reactance relay 1 stage (X1), a 2 stage reactance relay (X2), and a mower relay (M), the new setting value of each is referred to, for example, 90 of each value. % and 110% so that the simulated accident point occurs at the point on the line angle (x11 → x12 → x21 →
x22 → m1 → m2, the inspection signal is issued according to the inspection steps, and the system information path 29 to the relay is transmitted.
7,298 is switched to the inspection side and executed.

The information on the response results and automatic monitoring results of each relay element at this time is sent to the transmitting units 214 to 294 of the child devices in FIG. 2 to the relay units 215 to 29.
Since the transmitting unit 214 is already notified when the receiving unit 213 detects the synchronization word, the transmitting unit 214 uses the time when the synchronization word is detected as the time reference point to transmit the relay given to itself. The configuration is such that such information can be inserted into K#1 and K#2 in the response transmission word slots (see FIG. 3). Of course, this transmitter 214
Since the is also equipped with an electro-optical converter, the information of K#1 and K#2 converted into optical signals in this way is sent to the optical fiber FB1 via the corresponding optical inserter 212 (~294). and can be received by the parent device receiving section 14 of the main building 1.

In this way, the received response results and automatic monitoring results of the element relays can be displayed on the display section (not shown) of the monitoring panel 12, so the person on duty can grasp all of this information.

In other words, the functions described above ensure that the main building commands to change the setting of any relay element in each of the relay devices 21 to 29 installed at the site and that the instruction is automatically executed within the relay device. It can be seen that it is possible to confirm that there is a

FIG. 8 shows a more detailed explanation of the inside of 21 in FIG. 2, and has a configuration specifically showing the above-mentioned matters. In the figure, _D1 is a photoelectric converter, LC is a level changer,
SET is a signal line for transmitting setting change information, END is a signal line for transmitting setting end information, SYD is a signal line for transmitting synchronization word detection information, ROP is a signal line for transmitting relay operation information, SVS is a signal line for transmitting monitoring information, D is an electro-optical converter.

However, the above-mentioned known example
15419), optical splitters 211, 221, ..., 2 are placed at each protection relay section for signals sent via the optical fiber transmission line FB1.
91 and optical inserters 212, 222,..., 292
It is necessary to pay attention to the amount of attenuation at

In other words, the branch loss in the loop direction at each branch
L _LP [dB] and branch loss towards station L _ST
[dB] are equal, and taking into account losses such as connectors and splices, the typical values of L _LP and L _ST are L _LP = L _ST = 2L _CN + 2L _SP + L _K = (2 x 0.5 ^dB ) + ( 2 x 0.1 ^dB ) +6 ^dB = 7.2 ^dB , L _CN : Loss of optical connector (provided at both ends of the splitter) L _SP : Splice loss L _K : Branch loss of the splitter.

In addition, the inserter of each device also suffers a loss of passage loss L _TH [dB] to the loop side, and a typical value is 4.2 ^dB , as the result of the following equation.

L _TH = 2L _CN + 2L _SP + L _M = (2 x 0.5 ^dB ) + (2 x 0.1 ^dB ) 3 ^dB = 4.2 ^dB , L _M : Passage loss of the inserter Therefore, the first known example When there are nine protective relay devices 21 to 29 as shown in the figure,
The output of the device 21, that is, the output side of the inserter 212, suffers a loss of L _LP +L _TH = 7.2 ^dB + 4.2 ^dB = 11.4 ^dB from the incident light amount P _IN , and the output of the device 22, that is, the output of the inserter 212, On the output side of the device 222, the output of the device 29 is 2(L _LP +L _TH )=22.8 ^dB , that is, on the output side of the inserter 292, the incident light amount P _IN of the device 21 is 9(L _LP +L _TH )=102.6 ^dB . This results in more attenuation.

Usually, LEDs are used as light emitting elements, but
Considering the power incident on the optical fiber FB1, the output is approximately P _FIN = -10 dB _n at most, and even if the attenuation of the optical fiber transmission line is ignored, the reception level P _3IN of the device 3 is: P _3IN ^{= P} _FIN ⁻³ (L _{LP +}
This value is close to the PD reception limit.

This means that in the case of a loop transmission line, an active circuit is placed in the loop to convert the optical signal into an electrical signal and amplify it each time it passes through at least three devices (which can be thought of as three stations). , indicates that it is necessary to convert the received signal back into an optical signal after amplification and branch it to the loop direction and the station direction.

However, providing an active circuit in the station greatly impairs the system reliability of the loop transmission line, and this point is a major drawback of the known example.

Furthermore, it goes without saying that arranging such a large number of active circuits within the system brings about disadvantageous factors from an economic point of view. Furthermore, in the case of the loop transmission line method, there is a drawback that the signal level received at each device end varies greatly.

Also, in known systems, the power supply requires a signal amplifier, resulting in signal delay times. That is, due to time delays in the power supplies and signal amplifiers at each station, signal delays occur, for example, t1 at the first station, t2 at the second station, and tn at the nth station. Therefore, as a whole loop type transmission line, t1+t2+...
A signal delay of tn occurs, and an individual delay correction circuit is required for each station to correct this.

By the way, in the well-known protection of substations, it is necessary to sample the current and voltage at each terminal synchronously as input to a digital protective relay device. For example, in a bus protection relay device based on the differential principle, Even if there is a slight time difference (usually required to be 20 nanoseconds or less) between the sampling times of each terminal, a differential current will occur, which can cause malfunctions. Therefore, the signal delay due to the use of a loop transmission line must be strictly corrected, but in practice, it is possible to sample the delay on a loop transmission line of 2 to 3 km at the same time on all terminals. It is quite difficult to make such a delay. Furthermore, even if this were to be realized, it would be impractical because it would be necessary to stop the loop transmission line, and therefore the entire system, and make adjustments again when expanding power transmission and substation equipment.

In this way, the system using the known loop transmission line is suitable as a monitoring system that collects the operating status of each protective relay device or disconnector at the main building, but it is not suitable for the protection of substations. As a protective relay system, there are problems with signal attenuation during transmission and delay time compensation, and thus it cannot be adopted.

[Purpose of the invention]

From the above, it is an object of the present invention to provide a system in which signal attenuation and signal delay compensation are hardly a problem, and which is suitable as a protection relay system for a substation.

[Summary of the invention]

The key points of the present invention are as follows: (1) Almost uniform signal reception of optical signals input from each information detection point to a transmission path shared by the entire system to all terminals (it is convenient to place them at the same information detection point position); In order to make it possible to transmit signals at the same level (without placing a repeater amplifier using an active circuit in the middle of the transmission path, which is likely to lead to a reduction in reliability), the shared transmission path is connected to a star coupler. (2) One of the information detection devices is provided with a master clock, and the information detection devices are organized based on this clock. The transmitted transmission format (synchronization word and subsequent data word) is sent out to the star coupler, which is a shared transmission path, and each of the other information detection devices synchronizes with this transmission format and outputs the clock circuit at its own end. It regulates (corrects) synchronization, identifies the sampling of own-end data, and further identifies the transmission position (word slot) of own-end data in the transmission format, and sends the own-end sampling data to the star coupler at that time. (3) The protection relay device installed at each branch end of the star coupler, which is a shared transmission line, is equipped with a data receiving circuit to selectively share all data words related to its own protection function. It is configured so that it can be input from the transmission line.

[Embodiments of the invention]

Typical embodiments of the present invention are shown in FIGS. 1 and 6 below.
This will be explained using FIG.

FIG. 1 shows the connection relationship between a star coupler, which is a shared transmission path, an information detection device, and a protection relay device in an embodiment of the present invention.

In the diagram, FB _STAR is centered around the star coupler,
Each branch shows a shared transmission path consisting of an optical fiber cable, and the example in this figure shows the part related to a protection relay system corresponding to the protection range in Figure 5, and the number of branches in the star coupler is nine. Indicate the case. One of the major features of the present invention is that there is no active circuit on this shared transmission path. Device 2 connected to the end of each branch of this shared transmission line
1R, 22R, to 29R are equipped with an information detection device (function) and a protection relay device (function), and a typical embodiment thereof has a configuration as shown in FIG.

Among these, the information detection function 21RSD detects when a sample command is given from the input transformer unit 21S1 for guiding the system currents i _a to _ic , voltages va _{to vc} , etc., and the control circuit 21S7, which will be described later. Sample holder group 21S2 for sampling and holding at the same time, analog multiplexer 2 for multiplexing the outputs of these sample holder groups 21S2
1S3, an AD conversion circuit that converts its output into a digital quantity, a clock source 21S6, this clock source 2
A control circuit 21S7 that receives the output of 1S6 and creates the above-mentioned sample command, multiplexing switching command, AD conversion command, etc., and a PS conversion circuit that organizes the system information obtained by these circuits into a serial signal and outputs it. 21S5, and an electro-optical converter 21S8 which converts the output into an optical signal and outputs it. Of these, the control circuit 21S7 receives a clock correction signal from the protection relay function 21R/RV side, which will be described later, through a signal line L211 and the clock source 21.
It includes a phase lock circuit whose phase is controlled based on the clock signal from S6, and its output is used as a reference for generation times of various control signals.

On the other hand, the protection relay function 21R/RV is mainly composed of a digital protection relay unit 21R3, and the end unit closes the serial signal received from the coexisting transmission line via the optical add/drop unit LK21 and the electro-optical converter 21R1. By the conversion circuit 21R2,
After converting into parallel signals, only the data words necessary for self-determination of accidents can be taken in and the arithmetic processing according to the program stored in the self-internal memory can be executed to perform the determination.

The parallel/serial conversion circuit 21R2 sends received bit information, synchronization word detection information, etc. to the control circuit 21S7 of the information detection function 21RSD via a signal line L211.
It can be used as a clock correction signal to enable information sampling of that terminal to be performed synchronously for the entire system.

Note that if it is determined by the digital relay unit 21R3 that there is a system fault, the output circuit 2
A trip command is given to the breaker (not shown) via 1R4.

This terminal device 21R includes an optical add/drop unit LK2.
1 is provided, and the transmission line signal organized into the optical signal of the information detection function 21RSD is a coexistence transmission line.
It plays the role of guiding the information given to the coexistence transmission line F _STAR to the protection relay function 21RRV as well as guiding it to the F _STAR .

FIG. 7 shows each end device having the configuration shown in FIG. 6,
The transmission signal format on the star coupler F _STAR , which is the shared transmission path, in the embodiment when applied to a system as shown in FIG. 1 is shown in the top row, and the transmission signals (21RSD, 22
RSD, 23RSD, ..., 29RSD) are shown in order, and in the case of this figure, all 3
A case in which word data is sent is shown.

With this configuration, (1) Since the star coupler network does not pass through each terminal in series, signal attenuation on the network hardly becomes a problem. To explain this more quantitatively, a. Loss of star coupler with 9 branches L _STAR ≒10 dB b. Assume that the average distance from each terminal to another terminal is 300 m from both ends with the star coupler in the center. Assuming that the transmission loss of the system including the transmission loss of this optical fiber transmission line is
L _ST,LINK is expressed as L _ST,LINK =L _STAR +2(L _CN +L _SP +L _K +L _I +L _LINE ), and L _STAR , L _CN , L _SP , and L _K have the losses as described above _. is the insertion loss of the drop-adder = 3 dB, and L _LINE is determined by the loss of the optical fiber = 1 dB/Km.

This typical value is L _ST,LINK = 10 + 2 {0.5 + 0.1 + 6 + 3 + (1 x 0.3)} ≒ 30 (dB) using the above numbers, and the power incident on the optical fiber at the transmitting end
If P _FIN is considered to be −10 dB _n , the optical level of the received signal at each end is P _IN P _IN = −10 − 30 = −40 [dB _n ], which means that the optical level of the received signal at each end is P IN P IN = −10 − 30 = −40 [dB n ]. It can also be seen that no active circuitry is required and each end can also receive a uniform light level signal.

(2) As a result, there is no need for a relay amplifier, and signal delay time is almost no problem. By the way, the signal delay time per 1km of optical transmission lines is about 5 nanoseconds, so an average optical transmission line for a substation of about 2km will have a delay of about 10 nanoseconds, but this is due to the bus protection relay. Less than the 20 nanosecond delay time allowed by the device. Therefore, delay compensation is almost unnecessary.

(3) System-wide synchronous sampling can be easily achieved.

(4) Information necessary for the protection relay system can be obtained in a timely manner.

(5) The configuration of each protective relay device can be standardized.

It can be seen that the system of the present invention has excellent practical effects.

〔Effect of the invention〕

According to the present invention described above, a highly reliable and highly practical protective relay system can be obtained.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the electrical station configuration and the protection relay system of the present invention installed there, Figure 2 is a diagram of a signal transmission system for a conventionally known protection relay, and Figure 3 shows the contents of one frame of a transmission signal. Figure 4 is a diagram explaining how to check relay characteristics, Figure 5 is a diagram showing the electrical station configuration and a known protection relay system installed there, and Figure 6 is a diagram showing the equipment installed at each terminal. 21R to 29R, FIG. 7 is a diagram for explaining the signal transmission method when the protection relay system of FIG. 1 is used, and FIG. 8 is a diagram showing a part of the circuit of FIG. 2 in detail. FIG. 21R to 29R...Terminal device, FB _STAR ...Star coupler signal transmission line.

Claims (1)

[Scope of Claims] 1. A plurality of busbars, a power transmission line and a transformer connected to the busbars, a busbar connecting switch and a disconnector provided between the plurality of busbars, and a power transmission line and a transformer connected to the busbars, and a A protection relay system used in a substation where a power line connection disconnector and a transformer connection disconnector installed between a busbar and a transformer are installed, and the substation protection The relay system includes a bus bar protection relay device, a power transmission line protection relay device, and a transformer protection relay device installed in the substation premises,
and includes a star coupler network installed between these protective relay devices, on which a signal frame consisting of a synchronization word followed by a data word is periodically sent to the star coupler network. means are provided, each protective relay device coupled to the star coupler network having an information detection part and a protection relay part, the information detection part of each protection relay device detecting a synchronization word in the signal frame. synchronously self-terminal current,
The voltage is sampled simultaneously, and the current and voltage signals obtained as a result of the simultaneous sampling are sent to the star coupler network, which is placed at the position promised to its own terminal in the data word following the synchronization word of the period, and each The protective relay section of the protective relay device selects and obtains the information necessary for its own accident judgment from among the information in the data word from the star coupler network, and issues a tripping command to the corresponding disconnector. A substation protection relay system characterized by: