JPH01264525A - Digital protective relay device - Google Patents

Abstract

PURPOSE:To prevent a system from going down by replacing one module for processing, if its malfunction is detected, with another module contained in the same processor having the module. CONSTITUTION:A trouble detection module 2, a main relay input converter module 3 having the same hardware as that of the module 2, a main relay calculating module 4, a sequence processing module 5, doubled digital input/ output module 7a, 7b are connected to a system bus 11. The modules 2 and 3 back up each other in case of a trouble. A processor 41 of the module 4 and a processor 33 of the module 3 back up each other. A CPU II 44 of the module 4, a CPU II 54 of the module 5, a CPU I 51 of the module 5 and a CPU I 71a of a module 7a back up each other.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a protection relay device that detects an accident in an electric power system and protects the system. Specifically, the protection relay function is performed using a digital processor. [Prior Art] Conventionally, in a digital protection relay device, as a countermeasure in the event that an abnormality occurs in the protection relay device itself, Japanese Patent Application Laid-Open No. 59-1999
Techniques described in Japanese Patent Application Laid-open No. 6569 and Japanese Patent Application Laid-Open No. 62-33813 are known. According to these conventional technologies, the protective relay device is automatically inspected or constantly monitored, and if a defect is detected, the relay operation such as the output of a cutoff command is locked, and the function as a protective relay device is stopped. I have to. [Problems to be Solved by the Invention] However, according to the above-mentioned conventional technology, there is a problem in that when a defect occurs, all protection functions are stopped, resulting in a complete system down. In order to solve this problem, protective relay devices are duplicated, but this not only causes the problem of increasing the size of the device configuration, but even in this case, recovery and repair of defects is completed. Until then, the system becomes a single-layer system, resulting in a significant drop in reliability. SUMMARY OF THE INVENTION An object of the present invention is to provide a digital protection relay device that can prevent system failure due to occurrence of defects and can be made smaller. [Means for Solving the Problems] In order to achieve the above object, the present invention takes in various state quantities of the power system to be protected, performs protection relay calculation processing at regular intervals according to a predetermined processing procedure, and In a digital protection relay device that outputs protection commands to the power system based on the results, the processing means related to protection relay calculation processing is divided into multiple independent modules based on processing functions, and the same type of processor is installed in each module. A processor is installed in each module so that at least two modules are included, and when a failure in one module is detected, the processing function of the module is changed to one in which the same processor as the module is installed. Alternatively, the configuration is such that the processing is performed on behalf of a plurality of other modules. It should be noted that the proxy processing can be configured such that the processing functions of the own module and the defective module are performed alternately at the predetermined period. ``Furthermore, the proxy processing can be structured so that the processing functions of the own module and the defective module are divided and processed multiple times at the constant period.'' Further, the module that performs proxy processing can be configured to perform proxy processing using the same program as the program related to the processing function of the delegated processing module. Further, it is also possible to configure one module to include processors of the same type as all the processors installed in other modules, so that the one module performs the above-described proxy processing. [Operation] With this configuration, even if a defect occurs in one module, the processing function of that module or its processing function will be processed on behalf of one or more other modules that serve the same processor. The function as a protection relay device is self-restored, and system failure is prevented. In other words, the present invention is based on a structure in which functions are distributed to each module based on processing functions, and a processor is mounted on each module, and furthermore, the distributed structure is such that it includes modules mounted with the same type of processor. shall be. The configuration is such that proxy processing is performed on a module-by-module basis. Data can be transferred between each module via a standardized system bus or other bus. The proxy processing can be mutually performed between related modules, or only one module can have a proxy function. A processor that performs proxy processing includes programs for other processors that perform proxy processing in addition to programs related to its own processing functions. Since this program uses the same type of processor, almost the same program can be used. Note that if the functions are distributed so that the number of modules that perform proxy processing is selected to 1 or 2, the memory capacity (ROM) for storing the proxy processing program will necessarily increase, but the hardware I(, -ROM, etc.) will increase. This does not lead to an increase in the number of processors.Therefore, although it is possible to substantially obtain the reliability of duplication, it does not lead to an increase in the size of the device.Furthermore, during proxy processing, each processor performs both its own arithmetic processing and Alternate time-sharing processing is performed on the proxy calculations (for example, alternately at fixed calculation cycles), but state quantity data is taken in at fixed calculation cycles.As a result, the accuracy of protection relay calculations is reduced. There is no such thing.In addition,
The output of accident judgment may be delayed by one or several cycles depending on the time division method, but this is not a problem in practice. [Examples] The present invention will be described below based on Examples. FIG. 1 shows an overall configuration diagram of an embodiment of the present invention, and FIG. 2 shows a detailed configuration diagram of main parts. In this embodiment, system state quantity data such as voltage and current of the power system is input, and this input data is subjected to digital calculation processing according to the desired protective relay calculation algorithm to detect faults on power transmission lines or distribution lines. This is applied to a digital protection relay device that performs As shown in the figure, an auxiliary voltage and current transformer module 1 that inputs system voltage and current data, an accident detection calculation module 2, a main relay input conversion circuit module 3, a main relay calculation module 4, and a sequence processing/setting process. - An automatic monitoring module (hereinafter collectively referred to as a sequence processing module) is composed of a 5° setting display panel 6, digital input/output modules 7a and 7b, an auxiliary relay module 8, a communication interface module 9, and a power supply module 10. Note that the transformer module 1 receives voltage and
Current data is input. Auxiliary relay module 8
As a result of the accident determination. For example, a rip command to 1 is output to the circuit breaker CB. Among the above modules, modules 3 and 4. ．． 5°7a,
7b and 9 are connected to a standardized system bus 11, and data transfer is performed between them via this bus. Analog input data output from transformer module 1 is input to modules 2 and 3 via dedicated bus 12. Further, the accident detection calculation module 2 is connected to the main relay calculation module 4 and the sequence processing module 5 via a dedicated bus 13. This is to ensure data transfer between the modules 2, 4.5 even if the system bus 11 fails. On the other hand, the digital input/output module 7a,
Output signals such as trip commands output from 7b are input to the auxiliary relay module 8 via a dedicated bus 14. The functions of each module and the configuration of agency relationships will be explained using FIG. 2. Each module 2,3゜4.5.7a,
Each of 7b is an arithmetic module having a processor mounted thereon. Depending on the function, one or two digital signal processors DSP, sensor 1 heral processing units CPUI or CPUIT are provided. Here, an overview of each module and an overview of the processing of its processor will be explained. (1) Accident detection calculation module 2 This module 2 executes relay calculations related to well-known overcurrent relays and undervoltage relays. First, analog input data such as voltage and current is taken in every data sampling period, converted into digital quantities by the A/D converter 21, and then stored in the data memory 22. DSP23
is stored in data memory 2 according to program A in ROM 24.
After performing digital filter calculation using the data in 2 to remove harmonics in the input data, the above-mentioned accident detection calculation is performed. This calculation result is transferred to the module 4 or 5 via the dedicated bus 13. The DSP 23 has a known configuration as shown in FIG. As shown in the figure, address register ARIII,
Data register DR112, data memory RAMI 1
3. Multiplier circuit MPY114, arithmetic logic unit ALU115, accumulator ACC11
6. Instruction memory ROM1'17, control circuit C
It consists of an NT 118 and an internal bus 119. That is, the DSP can be programmed to
It is a type of one-chip microcomputer that can perform a variety of digital signal processing on a single chip. Moreover, in order to realize high-speed arithmetic operations, ■ a built-in multiplier and a 0
It adopts a pipeline architecture of multipliers and accumulators, and incorporates parallel processing descriptions using microprogramming. (2) Main relay input conversion circuit module 3 This module 3 is configured with the same hardware as the module 2, and takes in analog data via the bus 12.
Converter 31 converts into digital quantity and data memory 32
to be memorized. Then, the DSP 33 executes a digital filter operation for removing harmonics according to the program B stored in the ROM 34. This filter operation is performed on a plurality of inputs within the same π-definite operation cycle as the module 2. Furthermore, this calculation result is transferred to other modules. Note that the reason why common functions such as filter calculations are divided into modules 2 and 3 to have an overlapping configuration is to improve reliability. (3) Main relay calculation module 4 This module 4 uses the output data of the main relay human power conversion circuit module 3, and uses the program C1 in the ROM 42.
Accordingly, main relay calculations such as calculating the impedance of the power transmission line are performed at high speed by the DSP 41. The above output data from module 3 is CPTJ 144
The data is taken into the data memory 43 by. Others, CPU
The I44 has a function of controlling the transfer of the calculation result of 5P41 to the sequence processing module 5. CP U j
4.4 executes processing according to program C2 in the ROM 45. I) In addition to SP 4.1, CPU
4.4 is provided because the data transfer ability of the DSP 41 is generally poor and to improve reliability. (4) Sequence processing module 5 As shown in FIG. 2, cpur51. ROM52, data memory 53,
It consists of cpun+br and ROM55.
The CPU 54 executes the program D stored in the ROM 55.
In accordance with 2, the protection recency process and the automatic monitoring process are executed. On the other hand, the CPU 51 executes relay setting processing, panel display processing, etc. according to the program instructions in the ROM 52. (5) Digital input/output modules 7a, 7b These modules 7a and 7b are interfaces that execute input/output processing, and have a configuration in which the same modules are duplicated. The CPUs 171a and ’71b each have ROM7
Program Ei+'E2 stored in 2a and 72b
Execute t processing according to the following. Generally, it is constructed using a level conversion circuit, a line driver and receiver, and a photocoupler. Next, proxy processing according to a feature of the present invention will be explained in detail. As is clear from FIG. 2, each module is divided so that at least two processors of the same type are provided as a whole. As a result, when a defect occurs in one module, processing can be performed on behalf of another module by using the same type of processor and the same program. □ The agency relationship of modules in this embodiment is as follows. (2) Module 2 and module 3 can perform processing on behalf of each other. (2) If the DSP 41 of the module 4 is defective, the DSP 33 of the module 3 performs processing on its behalf. ■Module 4 and module 5 C, PUII44 and 5
3 can perform processing on behalf of each other. (2) If the CI (CI) UI 51 of the module 5 is defective, the CPtJI 71a of the module 7a performs processing on its behalf.・ ■CP of module '7a', '7b (JI71a, 7
1b can perform processing on behalf of each other. It is necessary to incorporate a proxy processing program for the above-mentioned corresponding proxy processing, and the ROM 24-. 34. . 4.2, 45, 52, 55.72a and 72b store their own programs as well as proxy processing programs. That is, the ROM 24 of module 2 stores program A of module 3 relating to proxy processing in addition to program A relating to its own module. As shown in the figure, other modules also store programs related to proxy processing. Since the DSP 41 of module 4 and the CPU 151 of module 5 do not perform processing on behalf of other processors, only the original programs C□ and Dl are stored, respectively. Next, the execution timing of proxy processing will be explained using FIG. 4. In FIG. 4, (a) shows the sampling timing (period) for converting voltage and current data of the power system into digital quantities. In this embodiment, the sampling period and the calculation period match, and the protection relay calculation and the like are completed in a predetermined arcoris 11 within this one sampling link interval. Same figure (b)
is a processing timing chart I- of module 3, which shows a case where module 2 related to proxy processing is normal. Therefore, only the original processing program B is repeatedly executed at each sampling period. That is, time period S1, -
0, import the data at time n-1, and then import the data at time period P.
At times 1 and -0, program B is executed using necessary data, including data taken in before time n-1, to perform a predetermined calculation. Similarly, n, n+1. n+2.
In this step, predetermined data acquisition and calculation are performed. Then, at the timing shown in FIG. 4(d), the processing results by program B are output for each sampling period. The processing of module 2 during normal operation is also shown in figure (b).
), and the processing results are output at each sampling period, as shown in Figure (d). Here, a description will be given of proxy processing when a defect occurs in the module 2. - Detection of the occurrence of a failure is performed by well-known means including a waste of timer, a parity check, etc., and a proxy processing command is given to the module 3 based on the failure detection. As shown in FIG. 4(c), the module 3 alternately executes the program A of the module 2 on its behalf and its own program B. Data input processing is performed in time slots 5n-0, Sn, and Sn+□ of every Sunblink cycle. Predetermined arithmetic processing is performed at every sampling period. Although the arithmetic processing is performed at intervals of two sampling periods, since the input data is taken in every time, the accuracy of the arithmetic processing can be maintained at the same accuracy as during normal operation. Note that the output timing of the calculation results by each of the programs A and B can be selected from the asynchronous method shown in FIG. 4(e) or the synchronous method shown in FIG. 4(f). Programs A and B are asynchronous.
It is applied when the calculation processing related to the above does not need to use input data at the same time, and each calculation uses the latest input data and outputs the calculation result within the calculation cycle. therefore,
As shown in FIG. 4(e), the calculation results of programs A and B are based on input data at times that are shifted by one. On the other hand, the synchronous method is applied when it is necessary to use input data at the same time due to the processing contents of programs A and B. First, the module 3 captures and stores input data at time n-1 in time zone Sn-□. Then, in the following time period Pn-0, the processing of program A is executed, and the calculation results are temporarily stored without being output. Next, data at time n is captured and stored in time zone Sn. The processing of program B to be performed in the subsequent time period Pn is performed using the input data at time n-1. At the same time as this processing is completed, the results of program B are output together with the results of program A (FIG. 4(f)). By doing so, it is possible to perform processing based on the same input data. Here, the processing procedure at the stage of transition from normal operation to proxy processing and the procedure for switching the interval sampling period during proxy processing will be explained with reference to FIG. What is shown in the figure is an outline of the processing of module 3. In step 121, the module 2 determines whether it is defective or not. If the module 2 is normal and not defective, the process proceeds to step 122, and after executing the original processing B of the module 3, the process proceeds to step 123 to update the sample period. Execute the same process repeatedly with double cycle. On the other hand, if module 2 is determined to be defective in step 121, the process proceeds to step 124, where a is set in the flag, and the process proceeds to step 125. Here, it is determined whether the content of the flag is b. In this case, since the flag is set to a in step 124, the determination in step 125 is negative, so step 1
Proceed to step 26. In step 126, as explained in FIG. 4(c),
The input data at the sampling time is captured and stored, and the processing program A of the defective module 2 is executed. After the processing of program A is completed, the process proceeds to step 127, sets the flag to b, proceeds to step 128, updates the sampling period by one sample, and returns to step 125. Then, in step 125 again, it is determined whether the flag is b. In this case, since the flag is set to b in step 127, the process proceeds to step 9, where the original processing program B of module 3 is executed as explained in FIG. 4(c), and the process proceeds to step 130, where the flag is set to a. set. Then, the process goes to step 128 again, updates one sample period, and returns to step 125. Thereafter, the processes of programs A and H are repeatedly executed in the same manner. In the above explanation, an example has been described in which a failure in module 2 in FIG. 2 is handled by module 3, but failures in other modules are handled in the same way by the corresponding other module described above. As mentioned above, since the processing related to the defective module is handled on behalf of another module by software without installing special hardware, it is possible to prevent the system from going down. It is possible to improve reliability and downsize the device. Also, from a different perspective, even if one module in the entire system becomes defective, it can be replaced by another module, making it possible to realize a highly reliable system that does not experience system downtime. In other words, even if a defect occurs in one module (printed circuit board), other modules handle the defect on behalf of the defect, so a digital protection relay device that can functionally recover by itself can be realized. In addition, the system only needs to be stopped when replacing a defective module, making online maintenance possible, which can be expected to significantly improve reliability, and eliminate system downtime, which has great practical benefits. big. The embodiment described above is an example in which all the functions of one failed module are processed on behalf of another module, and the processing timing is such that the original processing and the substitution processing are performed every other sampling period. Although an example has been described, the present invention is not limited to this, and the same effect can be achieved with the following configuration. For example, instead of performing proxy processing in one module, it is also possible to divide and implement the proxy processing program in multiple modules and perform the divided proxy processing on a faulty module in the multiple modules. That is, if the DSP 23 of module 2 in FIG. 2 fails, its function can be divided and processed by the I) SPs 33 and 41 of module 3 and module 4. Regarding the timing of arithmetic processing, in the above embodiment, an example was described in which all functions of a failed module are processed on behalf of one sampling period, but all functions are processed on behalf of a faulty module by dividing it over multiple sampling periods. You may also do so. Furthermore, it goes without saying that a module dedicated to proxy processing of defective sieves may be added to perform proxy processing of defective modules. The configuration of this proxy processing dedicated module can be as follows. e) All types of processors used in the system are implemented (in the example in Figure 2, there are three types (DSP, CI)).
Ul, CPU II) Executes exactly the same program as other modules. 1]) One type of processor performs processing on behalf of only the functions, although the program format, algorithm, etc. may be different (or may be the same). [Effects of the Invention] As explained above, according to the present invention, defects can be detected on a module-by-module basis, and all functions of the defective module can be handled on behalf of other normal modules, in other words, self-recovery is possible. Therefore, system failure can be prevented and high reliability can be achieved. In addition, since the processors involved in proxy processing are of the same type, programs with the same language and configuration can be used, and there is no increase in the number of hardware components, resulting in a compact and low-cost device. can be realized. In addition, during proxy processing, the input data related to the function of the defective module is exactly the same as when it is normal, so calculations related to protection relay calculations can be performed with high precision, resulting in high performance. A system 11 can be realized.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, and FIG.
Figure 3 is a block configuration diagram of the digital signal processor; Figure 4 is a timing chart explaining the timing of proxy processing in the embodiment; Figure 5 shows the procedure of an example of proxy processing. Flowchart 1. 2. Accident detection calculation module, 3. Main relay input conversion circuit module, 4. Main relay calculation module, 5 Sequence processing module, 7a, 7. b...Digital input/output processing module, 2
3.33.4-1...Digital signal processor, 5
1.71a, 71b-CPUI, 4.4.53-CPUn.

Claims (1)

[Claims] 1. Taking in various state quantities of the power system to be protected, performing protection relay calculation processing at regular intervals according to a predetermined processing procedure, and outputting a protection command to the power system based on the results. In the digital protection relay device, the processing means related to protection relay calculation processing is divided into a plurality of independent modules based on processing functions, and at least two or more modules each having the same type of processor installed are included. A configuration in which a processor is mounted on each module, and when a failure in one module is detected, the processing function of that module is processed on behalf of one or more other modules equipped with the same processor as that module. Digital protection relay device. 2. The digital protection relay device according to claim 1, wherein said proxy processing alternately performs processing functions for its own module and for a defective module at said fixed period. 3. The digital protection relay device according to claim 1, wherein said proxy processing is configured to divide the processing functions of the own module and the defective module over a plurality of times in said fixed period. 4. The digital protection relay device according to claim 1, wherein said module performing proxy processing is configured to perform proxy processing by the same program as a program related to the processing function of the delegated processing module. 5. The digital protection relay device according to claim 1, wherein one module is equipped with processors of the same type as all the processors installed on other modules, and the one module is configured to perform the proxy processing. .