JPS6152606B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an operation confirmation device for a protective relay (hereinafter referred to as a relay) in a power system. As an example of conventional technology, a distance relay for backup protection functions as a remote backup when the main protection relay is inoperable or the circuit breaker is inoperable, and can accurately identify the accident area. They are installed to quickly remove them and minimize the spread of accidents, and are generally used in combination with various distance relays. Since the setting of this distance relay affects the backup protection function mentioned above, the determination of the setting value plays an extremely important role. However, assuming the many patterns that change during operation in today's complex power systems, performing failure calculations and determining setting values requires a huge amount of effort, so it relies on the experience of maintenance personnel. There are many things. Moreover, since the electric power system is changing year by year due to expansion, etc., it cannot be said that there is no possibility of malfunction or malfunction with the setting values set as described above. The present invention provides a set value based on the online information of the equipment of the power system to be protected, the characteristics of the power system to be protected, the characteristics of the protection relay as a protection means, and the set value determined as described above. A device that automatically simulates failure phenomena while assuming many patterns that change in the operation of the power system in order to check the validity of the protection relay, and checks whether the protection relay operates correctly with the current set value. The purpose is to provide the following. The present invention will be described below with reference to the drawings.
FIGS. 1 and 2 show the hardware configuration and software functional blocks of the present invention, respectively. In FIG. 1, 11 is a device that measures data on equipment in the power system to be protected and reads the operating status of the equipment (hereinafter referred to as a system information measurement/detection device); 12 is a system information measurement device; - Information 11' built in the detection device 11
(generator voltage, active power, reactive power, transformer active power, reactive power, phase adjustment equipment capacity, tap value,
A device (hereinafter referred to as a system information transmitting device) that inputs information such as the opening/closing status of a disconnector and a disconnector, converts it into a signal suitable for transmission over a transmission line described later, and outputs it; 13 is a system information A dedicated communication line or a public communication line (hereinafter referred to as a transmission line) for transmitting the signal output by the transmitting device 12; 14 indicates each transmission line 1;
A device (hereinafter referred to as a system information receiving device) that receives the signal transmitted in step 3, converts it into information that can be stored in a system information storage section of a computer to be described later, and outputs the information.
15 is an electronic computer; 16 is a data storage device for storing system information, system characteristic data, relay characteristic data, failure calculation condition data, etc. to be described later; and 17 is a data storage device for setting data such as installation points of protective relays whose operation is to be checked. 18 is an input device for displaying and recording the results of the operation check. In FIG. 2, 14, 17, and 18 are the same as the system information receiving device, input device, and output device, respectively, explained in FIG. 1. 20 is a data section (hereinafter referred to as the system information storage section) that stores information on the current status of equipment in the power system to be protected; 21 is a data part that stores information on the current status of equipment in the power system to be protected; A data section to be stored (hereinafter referred to as a system characteristic data storage section) 22 inputs the information constructed in the system information storage section 20 and system characteristic data storage section 21 to detect failures necessary for checking the operation of the protection relay. A failure calculation condition creation section 23 automatically creates calculation conditions (system configuration to be calculated and assumed failure points), and a data section 23 stores failure calculation condition data created by the failure calculation condition creation section 22. (referred to as a calculation condition data storage unit); 24 is a failure calculation unit that inputs information in the failure calculation condition data storage unit 23 to perform failure calculation; 25 is a voltage of each equipment in the power system determined by the failure calculation unit 24; Failure calculation result data storage unit for storing current data, 26
27 is a data section (hereinafter referred to as a relay characteristic data storage section) that stores relay characteristic data and current setting value data of all protection relay installation points of the power system to be protected; 27 is a failure calculation result data storage section 25 and relay characteristic data; This is an operation confirmation calculation section that checks the validity of the set value of the protection relay to be inspected based on the information in the storage section 26. Next, the parts other than the electronic computer shown in FIG. 1 will be explained in detail. The system information measurement/detection device 11 measures generator voltage, active power, reactive power, transformer active power, reactive power, phase adjustment equipment capacity, tap value, and active power of transmission lines in the power system to be protected. It consists of a meter that measures reactive power and bus voltage, and a detection device that detects the opening and closing status of the disconnector and disconnector. Measured values can be obtained as analog or digital information. In the system information transmitting device 12, the analog information is passed to the scanner via the analog information input converter, and the digital information is passed to the scanner via the digital information input converter, and the scanner sequentially scans the input.
The analog information is further converted by an A/D converter,
It is passed as time-divided digital information to a transmission code converter, where the digital information is converted from parallel codes to serial codes, and finally modulated by a modulator and transmitted. The transmission path 13 is configured by a wired transmission method such as a communication line or a power line, or a wireless transmission method using microwaves. Furthermore, either a dedicated communication line or a public communication line can be used as the transmission line. In the system information receiving device 14, the signal transmitted via the transmission path 13 is received by the demodulator, encoded, and passed to the receiving code converter, where it is converted from serial code to parallel code, and sent to the distributor. Therefore, an operation is performed in which the information is output to the system information storage section 20 of the computer. Furthermore, each part of FIG. 2 will be explained in detail. There are different types of power system protection relays: main protection, back-up protection, distance relays, voltage relays, frequency relays, phase relays, which detect different physical quantities, and transmission lines, busbars, and transformers. There are many types of protection relays, including those for different target equipment, but here we will explain a distance relay for back-up protection of power transmission lines as an example. FIG. 3 is an impedance complex plan view showing relay characteristics and setting points of a distance relay for power transmission line backup protection. 31 represents the characteristics of the first stage distance relay, 32 represents the characteristics of the second stage distance relay, 33 represents the characteristics of the third stage distance relay, and 34 represents the characteristics of the fourth stage distance relay. X ₁ is the setting point of the first stage distance relay, X ₂ is the setting point of the second stage distance relay, M is the setting point of the third stage distance relay, Z
_AM , Z _ZL indicate the setting point of the fourth stage distance relay. The system information storage unit 20 stores generator voltage, active power, reactive power, transformer active power, reactive power, phase adjustment equipment capacity, tap value, transmission line active power, and reactive power in the power system to be protected. It stores current information on the voltage of the bus and the bus, and the open/closed status of the disconnector and disconnector. The system characteristic data storage unit 21 stores information about what kind of equipment (generators, transformers, transmission lines, busbars, breakers, disconnectors, etc.) the power system to be protected consists of,
It memorizes how these equipments are connected to each other, and also stores the electrical constants of each equipment (generator, transformer, impedance of power transmission lines, etc.). When the protection relay to be checked for operation is specified by the input device 17, the failure calculation condition creation section 22 creates failure calculation condition data in the steps shown by blocks in FIG. First, the current opening/closing status of the line breakers and disconnectors stored in the system information storage unit 20 and the connection relation information of each facility equipment stored in advance in the system characteristic data storage unit 21 are determined. Create a grid connection status and select failure points necessary for operation confirmation based on it. Next, for each selected fault point, considering the shunt effect, zero-sequence mutual impedance effect, or coordination of distance relays in front, we consider not only the current system configuration but also all the ranges that affect the settling. Changes in the system configuration are made by turning off the current system configuration or turning off disconnectors.
The created failure calculation condition data is stored in the failure calculation condition data storage section 23. A specific example of the processing in the failure calculation condition creation section 22 will be explained with reference to FIG. 5 and Table 1. In the system configuration example shown in FIG. 5, S indicates the installation point of the protection relay to be checked for operation, and f ₁ to f ₄ are the next bus line and the next bus line selected as the failure point. 51~
Reference numeral 59 indicates a disconnector that is turned off due to a change in system configuration. Taking fault point f ₁ as an example, 51 or 52 is set to simulate the current system (no operation of the disconnector = basic system) and the outage of the adjacent line of the transmission line to which the installation point S of the protection relay subject to operation check belongs. Failure calculations will be performed in three types of system configurations: systems with Noshi and disconnectors turned off. Table 1 summarizes this.

【table】

[Table] Note that FIG. 5 and Table 1 do not include all of the failure calculation condition data created by the failure calculation condition creation section 22. As will be described later in the explanation of the operation confirmation calculation unit 27, this is failure condition data for confirming the operation of the second stage distance relay shown in FIG. The failure calculation unit 24 calculates the measured values of the equipment in the protected power system stored in the system information storage unit 20, the types of equipment and their electrical constants, etc. stored in the system characteristic data storage unit 21. Based on the current system configuration and failure calculation condition data obtained by the failure calculation condition creation section 22, failure calculations for short circuits and ground faults are performed one by one for each failure point in each system configuration, and each Calculate the voltage and current of equipment (transformers, power lines, bus bars, etc.). The calculation results are stored in the failure calculation result data storage section 25. The operation confirmation calculation unit 27 calculates the voltage and current of each part stored in the failure calculation result data storage unit 25, the characteristics of the protection relay to be checked for operation extracted from the relay characteristic data storage unit 26, and the current setting value data. Automatically checks the operation of the protection relay. FIG. 6 is a block diagram showing the functions of the operation check calculation section, and each step will be explained below. (First step) Information on the voltage and current of each part calculated by the failure calculation creation unit 24 is retrieved from the failure calculation result data storage unit 25. (Second step) Relay characteristic data storage section 2
The characteristics and current setting value data of the protection relay to be checked for operation are extracted from 6. (Third step) From the data acquired in the first step, extract the values (voltage and current) necessary for checking the operation of the protective relay to be checked, and calculate the impedance using the following formula. Taking phase A as an example: Short circuit fault: Za=Va/ia Ground fault: Za=Va/ia+N ₁ (3i ₀ )+N ₂ (3i ₀ '
) (In the event of a ground fault, consider zero-sequence compensation from the installed circuit of the protective relay whose operation is to be checked and its adjacent circuit.) Here, ia: A-phase current of the installed circuit of the protective relay whose operation is to be checked a: Phase-A current of the installed circuit of the protective relay whose operation is to be checked. A-phase voltage at the installation point of the protective relay i ₀ : Zero-sequence current of the installation line of the protective relay to be checked for operation i ₀ ′ : Zero-sequence current of the line next to the installation line of the protective relay to be checked for operation N ₁ : Relay characteristic data storage Zero-sequence compensation coefficient N ₂ of the reactance element stored in the relay characteristic data storage unit 26 : Zero-sequence compensation coefficient of the Moh element stored in the relay characteristic data storage unit 26 This fault impedance is stored in the relay characteristic data storage unit 26 Impedance seen by the relay using CT ratio and PT ratio data Z _RY = Za×
Find the CT ratio/PT ratio. _ZRY represents the distance that the relay can see from the failure point, and operation will be checked based on this impedance. Taking the operation check of the second-stage distance relay in a three-terminal system as an example, the operating and non-operating responsibilities of the second stage are determined based on the distance seen by the relay at the time of the next bus failure or successive bus failure. The impedance _ZRY seen by the 16 types of relays shown in Table 1 can be obtained. (Fourth step) The impedance seen by the relay obtained in the third step is classified into operating duty and non-operating duty. Taking the same second-stage distance relay as above as an example, in this case, it is necessary to ensure that the next bus failure is included as the operational responsibility, and that the failure of one bus after another is not included as the non-operational responsibility, so Table 1. Shown in ~
Let the impedance seen by the relay when . (Fifth step) The current setting value of the relay subject to operation check corresponds to the operational responsibility determined in the fourth step,
Check whether it is reasonable by comparing it with non-operational obligations. Taking the same second stage distance relay as above as an example,
Maximun (Zai) <Current setting value of the relay subject to operation check <Minimun (Zbj) - [A] Here, Zai: Operational responsibility, that is, shown in Table 1 ~
Impedance seen by the relay at the time of failure Zbj: Checks whether it is the impedance seen by the relay at the time of failure shown in Table 1, that is, the non-operation duty. And display/
In order to output to the recording device 14, operating duties and non-operating duties that are acceptable with the current set values, and operating duties and non-operating duties that are incorrect with the current setting values are created as output data. The above are the functions of the operation confirmation calculation section 27. Finally, the display/recording device 14 is the operation confirmation calculation section 2.
The results of the operation confirmation divided in step 7, that is, all operational responsibilities and
Display and record whether the non-operation obligation is satisfied and, if not, what kind of failure it is for. As mentioned above, the above explanation has been given using the power transmission line backup protection relay as an example, but even if the equipment to be protected is different (busbar, transformer, etc.) or the type of relay is different, the fault calculation condition creation unit 22 The operation check can be performed using the same method, except that the algorithm in the operation check calculation section 27 is slightly different. As described above, according to the present invention, it is possible to easily check the validity of the setting value of the protective relay, which conventionally could not be said to be free from malfunction or malfunction, and to check the current system situation. Based on this, it is possible to automatically simulate failure phenomena and check them in detail while assuming many power system configurations that change during operation.

[Brief explanation of the drawing]

Figure 1 is a diagram showing a typical hardware configuration that realizes the present invention, Figure 2 is a functional block diagram of the software of the present invention, and Figure 3 is the characteristics of the distance relay and the distance relay determined by the present invention. Figure 4 shows a block diagram of the fault calculation condition creation section of the software mainframe. Figure 5 shows an example of a power system configuration showing examples of changes in failure points and system configuration. FIG. 6 is a diagram showing a block diagram of the operation confirmation calculation section of the main frame of the software. Explanation of symbols, 11...System information measurement/detection device, 12...System information transmission device, 13...Transmission path, 14...System information reception device, 15...Electronic computer, 16...Data storage device, 17 ...Input device as a peripheral device of a computer, 18...Output device as a peripheral device of a computer, 20...System information storage section, 21...System characteristic data storage section,
22... Failure calculation condition creation section, 23... Failure calculation condition data storage section, 24... Failure calculation section, 25...
... Failure calculation result data storage section, 26 ... Relay characteristic data storage section, 27 ... Operation confirmation calculation section, 31
...Characteristics of the first stage distance relay, 32...Characteristics of the second stage distance relay, 33...Characteristics of the third stage distance relay, 34...Characteristics of the fourth stage distance relay, X ₁ ...
Setting point of the 1st stage distance relay, X ₂ ... 2nd stage
Manufacturing point of stage distance relay, M... Setting point of 3rd stage distance relay, Z _AM , Z _ZL ... Setting point of 4th stage distance relay, ... Sensitivity angle, 51~
59...The off point of the breaker, _f1 to _f4 ...Failure point, S...The installation point of the protection relay to be checked for operation.

Claims (1)

[Claims] 1. A system information measurement/detection device that measures data on the equipment in the power system to be protected and reads the operating status of the equipment, and transmits the system information obtained by this system information measurement/detection device over a transmission path. A system information transmitting device that converts and transmits signals that are compatible with a system information receiving device that converts the information into information that can be stored in a system information storage section of the computer and outputs the converted information to the computer; and system information that is built into the computer and stores information on the current status of equipment in the power system to be protected. A storage unit, a system characteristic data storage unit that stores the types of equipment in the power system to be protected, their connection relationships, and electrical constants, and a system characteristics data storage unit that stores the types of equipment in the power system to be protected, their connection relationships, and electrical constants, and a system characteristic data storage unit that stores the types of equipment in the power system to be protected, their connection relationships, and electrical constants, and the protection relay specified by the input device provided as a peripheral device of the computer. Automatically creates the power system configuration and assumed failure points necessary for failure calculations from installation point information (terminal bus bars of power transmission lines, etc.), the contents of the system information storage section, and the contents of the system characteristic data storage section. The failure calculation condition creation section performs failure calculations according to the data in the failure calculation condition data storage section determined by this failure calculation condition creation section, and calculates the voltage and current of each equipment (transmission line, bus bar, etc.) in the power system. a failure calculation unit to obtain, a relay characteristic data storage unit that stores characteristics and current set values of protection relays installed in each equipment of the electric power system, which are stored in the system characteristic data storage unit;
The validity of the setting value of the protection relay is determined from the voltage and current of each equipment in the power system calculated by the failure calculation unit, the characteristics of the protection relay to be checked for operation extracted from the relay characteristic data storage unit, and the current setting value. It consists of an operation confirmation calculation unit to check, and an output device provided as a peripheral device of a computer to display or record the operation confirmation result of the operation confirmation calculation unit, and is a power system equipment that is subject to protection. Using online information, the characteristics of the power system to be protected, the characteristics of the protection relay that is the protection measure, and the current setting values, a computer is used to automatically calculate the power system, taking into account the many possible changes in the power system configuration during operation. A protection relay operation check device characterized in that it checks the operation of a protection relay by simulating a failure phenomenon.