JP5941339B2 - Digital protection controller - Google Patents

Description

  The present invention relates to a digital protection control device having an analog input correction and a function for holding the correction coefficient.

  In general, in a plant such as a power plant or a substation, electric power supplied to an electric power system is protected and controlled by a digital protection control device. Conventional digital protection control devices are described in, for example, “Second Generation Digital Relay Technical Committee,“ Second Generation Digital Relay ”, Electric Joint Research Group, Vol. 50 No. 1, 1994” Digital protection relays (second generation digital relays) are known. This type of digital protection control apparatus includes an input conversion unit, a digital arithmetic processing unit, a settling unit, a digital input unit, and a digital output unit. This input conversion unit is provided with a digital signal processing device including an analog filter for preventing aliasing errors, a sample hold circuit, a multiplexer, an A / D converter, and a buffer.

The digital arithmetic processing unit has a system bus, and performs processing such as data transfer and monitoring to various input / output boards and arithmetic boards connected to the system bus.
The digital protection control device is connected to the power system, digitally calculates the voltage and / or current values at the time of system fault, and disconnects the circuit breaker to disconnect the fault system when a predetermined range is exceeded. It has a function to output commands, and serves to protect the state of the system. It also contributes to stable power supply by measuring the voltage and current of the system, checking the state, and controlling the system.

  When protecting and controlling the state of the power system, highly accurate arithmetic processing may be required, and it is necessary to suppress the relay characteristic error to less than 1%. However, input / output gain errors, phase errors between input channels, etc. for auxiliary VT (Voltage Transformer: VT), auxiliary CT (Current Transformer: CT), and resistors in the input conversion unit connected to the system Will occur. For this reason, it is necessary to correct these errors. For example, a tester inputs a known voltage or current value to the input conversion unit during a shipping test, obtains a correction coefficient so that the A / D converted digital value matches the known input value, and calculates the correction coefficient. The data is stored in a non-volatile memory provided in the digital arithmetic processing unit. The digital protection control device always multiplies the correction coefficient (calibration value) by A / D converted digital data to correct the input value, thereby realizing an error of less than 1% in the relay characteristics and measurement accuracy ( For example, see Patent Document 1).

JP 2000-312431 A

  Since the correction coefficient stored in the non-volatile memory of the digital arithmetic processing unit is mainly error correction of the input conversion unit, it must be used in combination with the input conversion unit combined in the shipping test. Should an arithmetic processing unit fail, the corresponding arithmetic processing unit will be replaced, but when preparing a substitute, correction coefficient data of the input conversion unit is recorded in advance in the non-volatile memory of the arithmetic processing unit. It is necessary to let Therefore, the correction coefficient data is associated with a search key such as a storage destination, a device name, a product number, etc., and an FD (Floppy Disc: registered trademark), CD-ROM (Compact Disc-Read Only Memory), DVD-ROM (Digital Duplicates must be stored, stored and managed in various media such as Versatile Disk-Read Only Memory) and server database (DB).

  Conversely, if the input conversion unit fails, a substitute input conversion unit is prepared and replaced at the site where the digital protection control device is used. In this case, after replacement at the site, it is necessary to input a simulated voltage / current to the input conversion unit, and to perform adjustment work to determine the correction coefficient and a test to confirm it. It is the actual situation that hinders proper recovery.

  In addition, if the data stored in the non-volatile memory in the arithmetic processing unit is mistakenly recorded and operated with a different storage destination, device, or product number during field restoration, an incorrect system disconnection command is issued. There is a possibility of output to the circuit breaker. If this happens, stable power supply may not be possible, so the recording and operation of correction coefficients is a very important task and management.

  From the above situation, there has been a demand for a method that can save the trouble of searching for the correction coefficient during the field restoration work and prevent the correction coefficient from being recorded.

  The digital protection control device according to one aspect of the present invention includes an input conversion unit that performs a predetermined conversion process on an analog signal input from the power system, and converts the analog signal converted by the input conversion unit into a digital signal. An arithmetic processing unit that performs arithmetic processing for protecting and controlling the power system and outputs a command based on the calculation result, and an output unit that outputs the command output from the arithmetic processing unit to the outside. A non-volatile memory that records a correction coefficient for correcting an error of the input conversion unit is mounted in the input conversion unit.

According to at least one aspect of the present invention, it is possible to save the trouble of searching for a correction coefficient during a field restoration operation, and to prevent a correction coefficient recording error. In addition, since the adjustment work for the correction coefficient at the site is eliminated and the confirmation work is also eliminated, the recovery time can be greatly shortened.
Further, it is not necessary to store and manage the correction coefficient by using an external recording medium, thereby reducing the cost.

It is a block diagram which shows the 1st structural example of the conventional digital protection control apparatus. It is a block diagram which shows the 2nd structural example (main-FD structure) of the conventional digital protection control apparatus. It is a block diagram which shows the 3rd structural example (separate structure of the A / D conversion part and arithmetic processing part in multipoint analog input) of the conventional digital protection control apparatus. It is a figure explaining the management of the correction coefficient in the 1st structural example of the conventional digital protection control apparatus. It is a block diagram which shows the structural example of the digital protection control apparatus which concerns on one Embodiment of this invention. It is a figure which shows adjustment, storage, and management which obtain | require the correction coefficient of the digital protection control apparatus concerning one Embodiment of this invention. It is a block diagram which shows the principal part of the structural example of the digital protection control apparatus which concerns on the modification of one Embodiment of this invention. It is a flowchart which shows the correction coefficient monitoring process of the digital protection control apparatus which concerns on one Embodiment of this invention.

Hereinafter, an example of an embodiment for carrying out the present invention will be described with reference to the accompanying drawings. The description will be given in the following order. In addition, in each figure, the same code | symbol is attached | subjected to the common component and the overlapping description is abbreviate | omitted.
1. Supplementary explanation of conventional technology Description of one embodiment (example in which a non-volatile memory is arranged in the input conversion unit)
3. Modified example

<1. Supplementary explanation of conventional technology>
In order to specifically explain the difference between the digital protection control apparatus according to the present invention and the conventional digital protection control apparatus, the configuration of the conventional main digital protection control apparatus will be described below.

FIG. 1 is a block diagram showing a first configuration example of a conventional digital protection control apparatus.
The digital protection control apparatus 100 shown in FIG. 1 includes an input conversion unit 110, an arithmetic processing unit 120, a settling / display unit 130, an input / output unit 140, and a control power supply unit 150. The input conversion unit 110 and the arithmetic processing unit 120 are connected by a transmission path 115. For the transmission line 115, for example, a general cable or a backboard can be used. Power is supplied from a control power supply unit 150 to which a D / D converter or the like is applied, except for the input conversion unit 110.

  The digital protection control device 100 takes in voltage / current information (analog signal) at the time of an accident such as a short circuit or ground fault of the power system 101. A plurality of analog signals for each protection element (channel) are input from the power system 101 to the input conversion unit 110, and are sent to the analog filter (denoted as A / F) 121 of each channel in the arithmetic processing unit 120 via the transmission path 115. Entered.

  The arithmetic processing unit 120 removes unnecessary high-frequency components from the analog signal to which the A / F 121 of each channel is input, and outputs it to the multiplexer (denoted MPX) 122. The MPX 122 outputs the analog signal of each channel to the analog / digital converter (A / D) 123 in a time division manner. The A / D 123 converts the input analog signal into a digital signal of binarized information and outputs it to a DPRAM (Dual Port RAM) 124. A CPU (Central Processing Unit) 125 performs relay arithmetic processing on the digital data temporarily held in the DPRAM 124 according to a predetermined algorithm, and outputs the result to the settling / display unit 130 and the input / output unit 140.

  Based on the calculation result, a command is output from the input / output unit 140 to the external device 102, and the power system 101 is shut off or turned on to realize protection of each device and stable and safe power supply. An external contact signal supplied from the external device 102 is input to the arithmetic processing unit 120 via the input / output unit 140 and is used as a condition for relay arithmetic processing.

  The digital protection control device 100 is required to calculate with high accuracy and corrects an error generated in the input conversion unit 110. The correction coefficient obtained by adjusting and combining the input conversion unit 110 and the arithmetic processing unit 120 is recorded in a nonvolatile memory (Electrically Erasable and Programmable Read Only Memory) 126 to which an EEPROM or the like in the arithmetic processing unit 120 is applied. . Using this correction coefficient, the CPU 125 corrects the error by multiplying the analog voltage / current information input from the input conversion unit 110 by the analog / digital converted value, and executes the relay calculation processing of the determined algorithm. The power system 101 is monitored.

Here, in the unlikely event that the arithmetic processing unit 120 fails, in order to restore the local site, a substitute for the arithmetic processing unit 120 is prepared and the local recovery operation is performed. The correction coefficient suitable for 110 must be recorded in the nonvolatile memory 126 in advance. For this reason, it is necessary to store and manage these correction coefficients, and when an incorrect correction coefficient is recorded due to a human error or the like and the site is restored, an incorrect power system 101 shut-off and input command is output. There is a possibility that the power supply will not be stable and safe.
In addition, there is an operation for confirming whether the correction coefficient recorded in the nonvolatile memory 126 is correct as one of the on-site recovery operations. If the number of input points is large, it may take a long time until the recovery. This too can affect stable and safe power supply. In addition, the operation of confirming the relay characteristics of the digital protection control device based on the corresponding correction coefficient also occurs and has a very long time.
Conversely, when the input conversion unit 110 fails, a substitute is prepared in the same manner, but after obtaining the substitute correction coefficient, the correction coefficient is stored in an external recording medium such as an FD or CD-ROM. After this storage, it is necessary to transfer the data to the non-volatile memory 126 in the arithmetic processing unit 120 of the local digital protection control device 100, or to perform adjustment work on the site and obtain a correction coefficient. Recovery cannot be completed in a short time.
These events also apply to the following two conventional digital protection control devices.

FIG. 2 is a block diagram showing a second configuration example (main-FD configuration) of a conventional digital protection control apparatus.
The digital protection control device 200 shown in FIG. 2 includes a main arithmetic processing unit 220A, an FD (accident detection) arithmetic processing unit 220B, and a main input / output unit 240A and an FD input / output unit 240B connected to the main arithmetic processing unit 220A. This is an improved configuration. The input conversion unit 210, the transmission path 215, the settling / display unit 230, and the control power supply unit 250 correspond to the input conversion unit 110, the transmission path 115, the settling / display unit 130, and the control power supply unit 150 illustrated in FIG.

The digital protection control device 200 takes in voltage / current information (analog signal) of the power system 201, inputs an analog signal to each channel of the input conversion unit 210, and supplies it to the main arithmetic processing unit 220A and the FD arithmetic processing unit 220B, respectively. Is done.
Then, the supplied analog signal is relay-calculated by the main arithmetic processing unit 220A and the FD arithmetic processing unit 220B, and the result is output to the main input / output unit 240A and the FD input / output unit 240B, respectively. Then, the output of the main input / output unit 240A and the FD input / output unit 240B is commanded to the external device 202 with an AND configuration. By doing so, an erroneous command is not transmitted to the external device 202 due to a single failure of the main arithmetic processing unit 220A, the FD arithmetic processing unit 220B, the main input / output unit 240A, and the FD input / output unit 240B. It has become.

  In the main arithmetic processing unit 220A and the FD arithmetic processing unit 220B of the digital protection control device 200, correction coefficients necessary for high accuracy of arithmetic processing are transferred to the nonvolatile memory 126 via the parallel bus 127 connected to the CPU 125. It is recorded. Almost the same correction coefficient is recorded in the nonvolatile memory 126 of the main arithmetic processing unit 220A and the FD arithmetic processing unit 220B.

FIG. 3 is a block diagram showing a third configuration example of a conventional digital protection control apparatus.
The digital protection control device 300 shown in FIG. 3 has a configuration in which the number of analog input points is large, and the reliability is improved by separating the A / D unit and the arithmetic processing unit that perform analog / digital conversion. The input conversion units are also separated into input conversion units 310-1 to 310-n corresponding to the number of A / D units.

The digital protection control device 300 receives voltage / current information of a large number of channels from the power system 301 at the input conversion units 310-1 to 310-n. Each of the input conversion units 310-1 to 310-n inputs the received analog signal to the main_A / D units 360A-1 to 360A-n and the FD_A / D units 360B-1 to 360B-n.
The A / D units 360A-1 to 360A-n and the FD_A / D units 360B-1 to 360B-n convert the input analog signals into digital signals.
Next, each of the main arithmetic processing unit 320A and the FD arithmetic processing unit 320B performs relay arithmetic processing on the analog / digital converted digital data with a predetermined algorithm. And the result is instruct | indicated to the external apparatus 302 by AND structure via the main input / output part 340A and FD input / output part 340B.

  In the main_A / D units 360A-1 to 360A-n and the FD_A / D units 360B-1 to 360B-n of the digital protection control device 300, correction coefficients necessary for high accuracy of arithmetic processing are stored in the CPU. The data is recorded in the nonvolatile memory 126 via the connected parallel bus 127. In the nonvolatile memories 126 of the main_A / D units 360A-1 to 360A-n and the FD_A / D units 360B-1 to 360B-n, substantially the same correction coefficients are recorded.

  As described above, there are main conventional configurations shown in FIGS. 1 to 3, but the correction coefficient recording, storage, and management methods are common, and the common problems described above are present.

  Hereinafter, adjustment, storage, and management for obtaining a correction coefficient by a digital protection control device having a conventional configuration will be described.

FIG. 4 is a diagram for explaining management of correction coefficients in the first configuration example of the conventional digital protection control apparatus.
Conventionally, the arithmetic processing unit 120 in the digital protection control device 100 has a nonvolatile memory 126 connected to the CPU 125 by a parallel bus 127. A known voltage / current input 103 for analog adjustment is applied to the input section of the input conversion section 110, and the correction coefficient is set so that the digital value A / D converted in the arithmetic processing section 120 matches the equivalent of the known input value. Ask for. Then, the correction coefficient is recorded in the nonvolatile memory 126 provided in the arithmetic processing unit 120.

  The correction coefficient recorded in the nonvolatile memory 126 is necessary when the arithmetic processing unit 120 is incompatible, and must be stored and managed in the external recording medium 104 such as an FD, CD-ROM, or HDD.

<2. Description of an embodiment>
In order to improve the inconveniences of the above-described conventional digital protection control apparatus and to perform highly accurate digital arithmetic processing, the input conversion unit is provided with a correction coefficient for error correction of the input conversion unit.

(1) The error correction up to now is performed by integrating the auxiliary VT, auxiliary CT, analog filter (A / F), multiplexer (MPX), and analog / digital converter (A / D) of the input conversion unit. In recent years, however, multiplexers and those with less A / D error have been developed. As for A / F, by using resistors, capacitors, and operational amplifiers with very small errors, the errors are extremely small, and no error correction other than the input conversion unit is required.
(2) By making the auxiliary VT of the input conversion unit and the auxiliary CT smaller, and improving the processing capability of the arithmetic processing unit, a digital protection control device is configured with one unit, and the effects of noise and physical The control power is also supplied to the input conversion unit that could not supply the control power because of the structure.
(3) Since the correction coefficient has been used in the arithmetic processing unit so far, a rewritable nonvolatile memory has been provided and recorded therein. However, it is possible to increase the capacity of the non-volatile memory having a high-speed transmission and a serial interface by the development of the serial communication technology and supply the control power of the above (2), and the serial non-volatile memory is mounted on the input conversion unit.
(4) Correction obtained by adjusting the serial nonvolatile memory mounted on the input conversion unit and the CPU of the arithmetic processing unit by, for example, multi-master serial communication (I2C, etc.) and adjusting in combination with the input conversion unit during the shipping test Record the coefficient. As a result, the correction coefficient is recorded in the nonvolatile memory in the input conversion unit that requires error correction, and does not depend on other parts such as the arithmetic processing unit.
(5) Further, it is not necessary to save and store the correction coefficient data after the adjustment work at the shipping test in the external recording medium.

Hereinafter, a digital protection control apparatus according to an embodiment of the present invention will be described.
FIG. 5 is a block diagram showing a configuration example of the digital protection control apparatus according to the embodiment of the present invention. A digital protection control device 500 shown in FIG. 5 includes an input conversion unit 510, an arithmetic processing unit 520, a settling / display unit 530, an input / output unit 540, and a control power supply unit 550 in which a nonvolatile memory 511 is mounted. . The arithmetic processing unit 520 is a microcomputer. The input conversion unit 510 and the arithmetic processing unit 520 are connected by a transmission path 515. For the transmission line 515, for example, a general cable or a backboard can be used. Power is supplied from a control power supply unit 550 to which a D / D converter or the like is applied.

  The digital protection control device 500 takes in voltage / current information (analog signal) at the time of an accident such as a short circuit or ground fault of the power system 501. A plurality of analog signals are input to the input conversion unit 510 for each protection element (channel) from the power system 501, and predetermined conversion processing is performed on these analog signals by the auxiliary VT and auxiliary CT of the input conversion unit 510. . Then, the signal is input to the analog filter (A / F) 521 of each channel in the arithmetic processing unit 520 through the transmission path 515.

  The arithmetic processing unit 520 removes unnecessary high-frequency components from the analog signal to which the A / F 521 of each channel is input, and outputs it to the multiplexer (MPX) 522. The MPX 522 outputs the analog signal of each channel to the analog / digital converter (A / D) 523 in a time division manner. The A / D 523 converts the input analog signal into a digital signal of binarized information and outputs it to a DPRAM (Dual Port RAM) 524 which is an example of a buffer unit. A CPU (Central Processing Unit) 525, which is an example of a control unit, performs relay arithmetic processing on digital data temporarily held in the DPRAM 524 according to a predetermined algorithm, and the result is set and displayed / display unit 530 or an input / output unit. Output to 540.

  Then, a command is output from the input / output unit 540 to the external device 502 based on the calculation result, and the power system 501 is shut off or turned on, thereby realizing protection of each device and stable and safe power supply. An external contact signal supplied from the external device 502 is input to the arithmetic processing unit 520 via the input / output unit 540 and used as a condition for the relay arithmetic processing.

The digital protection control device 500 is required to calculate with high accuracy, and in order to improve relay characteristics and measurement accuracy, a technique for correcting a variation error caused by making each device is used.
The error correction is performed by adjusting a combination of the input conversion unit 510 and the arithmetic processing unit 520 to obtain a correction coefficient for correcting the error, and the correction coefficient is stored in the non-volatile memory 511 of the input conversion unit 510 that controls the error. Record. As the nonvolatile memory 511, for example, a serial EEPROM can be used. The CPU 525 of the arithmetic processing unit 520 and the non-volatile memory 511 are connected by the serial communication 527, and when necessary, the memory contents (correction coefficient) of the non-volatile memory 511 are read and the voltage / current information input from the input conversion unit 510 is read. Correction is performed by multiplying digital data obtained by analog / digital conversion of analog values by a correction coefficient. And about this correction content and an external contact signal, the relay calculation process of the program recorded on ROM526 which is an example of a memory | storage part is implemented, and the electric power grid | system 501 is monitored.

  Hereinafter, adjustment, storage, and management for obtaining a correction coefficient by the digital protection control apparatus according to the present embodiment will be described.

FIG. 6 is a diagram showing adjustment, storage, and management for obtaining the correction coefficient of the digital protection control apparatus according to the embodiment of the present invention.
In the present embodiment, a non-volatile memory 511 is mounted on the input conversion unit 510 in the digital protection control device 500, and the non-volatile memory 511 is connected to the CPU 525 of the arithmetic processing unit 520 via the serial communication 527. A known voltage / current input 503 for analog adjustment is applied to the input unit of the input conversion unit 510, and the correction coefficient is adjusted so that the digital value A / D converted in the arithmetic processing unit 520 matches the equivalent of the known input value. Ask for. Then, the correction coefficient is recorded in a nonvolatile memory 511 provided in the input conversion unit 510.

In general, the correction coefficient includes errors of the auxiliary VT and auxiliary CT of the input conversion unit 510, an analog filter (A / F) and a multiplexer (MPX) implemented in the arithmetic processing unit 520, an analog / digital converter (A The error of each element of / D) is also reflected. The error of resistance elements, capacitors, and operational amplifiers that make up A / F in recent years is a value that does not need to be corrected. Similarly, MPX and A / D are also improved in performance, so errors are dominant. It is only the input conversion unit. For this reason, the error of the arithmetic processing unit 520 can be ignored, and the correction coefficient is recorded in the nonvolatile memory 511 in the input conversion unit 510 in which the error is dominant and the error is dominant.
In addition, since the capacity and versatility of the serial nonvolatile memory are improved, it is possible to perform communication with reduced wiring and to disconnect the nonvolatile memory 511 from the arithmetic processing unit 520.

  As a result, even when the arithmetic processing unit 520 breaks down, it is not necessary to record the correction coefficient in advance in the substitute arithmetic processing unit. Therefore, storage and management in the external recording medium 104 such as an FD, CD-ROM, or server DB are possible. There is no need to do. Restoration work can be completed only by conducting a combination test with the input conversion unit at the site, so the site restoration time can be greatly reduced.

  When the input conversion unit 510 fails, an adjustment operation is performed in advance in combination with a calculation processing unit for adjustment, and the value is recorded in a non-volatile memory in the input conversion unit as a substitute. Since the correction coefficient is the correction coefficient for the auxiliary VT and auxiliary CT of the input conversion unit 510, no on-site confirmation test or on-site adjustment work is required, and the recovery time can be greatly shortened.

As described above, according to the present embodiment, the correction coefficient is stored in the non-volatile memory in the input conversion unit, so that it does not take time for local restoration when the input conversion unit or the arithmetic processing unit fails.
Further, troublesome storage and management of correction coefficients such as storing correction coefficients in an external recording medium is not required.
In addition, it is possible to provide a digital protection control device having a function capable of recording a correction coefficient with an inexpensive circuit configuration. Therefore, it can be realized even for a large-scale protection control device that requires a plurality of voltage / current signals, and management of the correction coefficients that have been conventionally required becomes unnecessary. Opened.

<3. Modification>
FIG. 7 is a block diagram showing a main part of a configuration example of a digital protection control device according to a modification of the embodiment of the present invention.
In the example of FIG. 7, the non-volatile memory 511 mounted on the input conversion unit 510 and the correction coefficient read by the CPU 525 mounted on the arithmetic processing unit 520 for the relay arithmetic processing are the volatile data mounted on the arithmetic processing unit 520. This is an example of recording in a memory 528 (for example, RAM) and utilizing it. In this case, it is necessary to confirm and monitor whether or not the correction coefficient recorded in the volatile memory 528 is always correct (matched), and the following processing is executed as a technique.

FIG. 8 is a flowchart showing the correction coefficient monitoring process of the digital protection control apparatus according to the embodiment of the present invention.
First, the CPU 525 of the arithmetic processing unit 520 reads the correction coefficient from the nonvolatile memory 511 of the input conversion unit 510 and calculates the sum value. Then, the correction coefficient and the sum value are transferred to the volatile memory 528 of the arithmetic processing unit 520 (step S1).
Next, the CPU 525 calculates the sum value (A) of the correction coefficient recorded in the volatile memory 528 of the arithmetic processing unit 520 (step S2).
Next, the CPU 525 collates the calculated sum value (A) with the transferred sum value (B) (step S3).
Next, the CPU 525 determines whether or not the calculated sum value (A) is different from the transferred sum value (B) (step S4). When the calculated sum value (A) and the transferred sum value (B) are the same, the CPU 525 performs a relay calculation process (step S5). After the process of step S5 is completed, the correction coefficient monitoring process is terminated.

  On the other hand, if the calculated sum value (A) is different from the transferred sum value (B), the CPU 525 determines whether or not the collation processing has been performed a specified number of times (step S6). If the specified number of times has not been performed, the processes in steps S2 to S4 are executed again.

  If the calculated sum value (A) is different from the transferred sum value (B) even if the verification process is performed a specified number of times (YES in step S6), the CPU 525 outputs an alarm (step S7). . Alternatively, an alarm may be displayed on the settling / display unit 530. After the process of step S7 is completed, the correction coefficient monitoring process is terminated.

  The above process is performed at the initial time and in a cycle that does not interfere with the relay calculation process, and it is constantly monitored whether the correction coefficient recorded in the volatile memory 528 is always correct.

  By performing the above processing, the data in the two memories of the nonvolatile memory 511 and the volatile memory 528 can be monitored, and the reliability of the relay calculation processing is ensured by guaranteeing the accuracy of the correction coefficient. Secure.

  The conventional digital protection control apparatus shown in FIGS. 1 to 3 also has an operation of duplicating the memory in the arithmetic processing unit, and may include a volatile memory in addition to the nonvolatile memory 126. In that case, in order to ensure the reliability of the relay calculation process, the corresponding nonvolatile memory 126 and the correction coefficient stored in the volatile memory are transferred to the external recording medium 104, and then the two nonvolatile elements in the local calculation processing unit Record in memory. Alternatively, the correction coefficient is adjusted on site, and the adjusted correction coefficient is reliably recorded in the two nonvolatile memories in the arithmetic processing unit. Thus, when the nonvolatile memory in the arithmetic processing unit is duplicated, more complicated work is required, and it has become more difficult to complete the local restoration in a short time.

  Of course, the digital protection control device according to the above-described embodiment is applicable not only to a general digital protection control device but also to other configurations. For example, a configuration in which the arithmetic processing unit as shown in FIG. 2 is duplicated for main and FD, or there are a large number of analog input points as shown in FIG. 3, and there are many arithmetic processing units and A / D units. The present invention can also be applied to configurations that are separated from each other.

(Other)
Note that the present invention is not limited to the above-described embodiments, and includes other modifications and application examples without departing from the gist of the present invention described in the claims.
For example, the above-described exemplary embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. . Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each exemplary embodiment.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Further, each of the above-described configurations, functions, and the like may be realized by software for interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be held in a recording device such as a memory, a hard disk, or an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or an optical disk. . Further, in this specification, the processing steps describing time-series processing are not limited to processing performed in time series according to the described order, but are not necessarily performed in time series, either in parallel or individually. The processing (for example, parallel processing or object processing) is also included.

  In addition, the control lines and information lines are those that are considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

  500 ... Digital protection controller, 510 ... Input conversion unit, 511 ... Non-volatile memory, 520 ... Operation processing unit, 525 ... CPU, 526 ... ROM, 528 ... Volatile memory, 530 ... Settling / display unit, 540 ... Input / output Part

Claims (2)

An input conversion unit that performs a predetermined conversion process on an analog signal input from the power system;
An operation for generating an error that is negligibly small compared with an error generated in the input conversion unit, converting the analog signal converted in the input conversion unit into a digital signal, and protecting and controlling the power system A processing unit that performs processing and outputs a command based on the calculation result;
The input conversion portion, and a non-volatile memory for recording the correction coefficient for correcting the errors caused by the combination of the arithmetic processing unit and the input conversion unit,
The arithmetic processing unit reads the correction coefficient recorded in the nonvolatile memory in the input conversion unit, and multiplies the value obtained by converting the analog signal input from the power system into the digital signal by the correction coefficient. A digital protection control device that performs correction together and performs the arithmetic processing using the corrected value . A volatile memory is provided in the arithmetic processing unit,
Wherein the arithmetic processing controller unit mounted in section calculates the first sum value from the correction coefficient recorded in the nonvolatile memory in the input conversion unit, the first sum value together with the correction factor the recorded and transferred to the volatile memory in the processing unit, said calculated from the stored in the volatile memory correction factor of the second sum value, the first calculated and the transfer was the first sum value by comparing the two sum values, the digital protective control according to claim 1 to monitor whether the correction coefficient recorded the non-volatile memory the recorded the correction coefficient in the volatile memory matches apparatus.