JP3879468B2 - Digital control / protection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital protection / control apparatus, and more particularly, a digital control suitable for executing failure monitoring on a random access memory storing analog input data and protection / control operation result data and outputting the monitoring result to the outside. -Concerning protection devices.
[0002]
[Prior art]
As a conventional device of this type, for example, a digital protection relay (second generation digital relay) described in Electric Cooperative Research Vol. 50 No. 1 is known.
[0003]
This device includes an analog input unit, a digital input unit, an arithmetic processing unit, and a digital output unit. The arithmetic processing unit has a microcomputer for executing protection / control arithmetic processing, a random access memory for data storage, and a protection / control arithmetic program. A read-only memory for storage is provided. In addition, this device is divided into an input board for digital filter processing using high-speed sampling data and an arithmetic board for protection control computation. The input board is mainly sampled and digital filter computation is performed. The analog input value is then passed to the protection calculation unit. The protection arithmetic board inputs the above data into the random access memory, executes the protection / control arithmetic program stored in the read-only memory once at an electrical angle of 30 ° with the microcomputer, and executes arithmetic processing.
[0004]
In this device, for each printed circuit board having a microcomputer, predetermined data is written to and read from all areas of the random access memory, and the data is checked for consistency, thereby electrically monitoring faults. It is configured to execute once at an angle of 30 ° and finally output abnormality information to a panel display, LED display, or an external device.
[0005]
[Problems to be solved by the invention]
When the above conventional technology (Electric Cooperative Research Vol. 50 No. 1) is applied, the following problems occur.
[0006]
In other words, only a read / write check that writes and reads predetermined data to all areas of the random access memory and checks that the data matches is a single failure in the area of the random access memory that stores the monitoring results. If there is, the monitoring result cannot be stored correctly, and the correct result cannot be output to the external device. In other words, in the read / write check, a monitoring blind spot occurs in the memory area for storing the monitoring result.
[0007]
The present invention has been made in view of the above points, and an object of the present invention is to provide a digital control / protection device having a mechanism for executing failure monitoring of a random access memory without blind spots.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises the following means.
[0009]
That is, an analog input means, a digital input means for taking in external device information, an arithmetic processing section for executing a predetermined arithmetic program on the input data to the analog input means, and an operation result of the arithmetic processing section are output. A digital control / protection device that includes a digital output unit that communicates with a communication network, executes processing according to a predetermined protection / control operation, and issues an operation command to an external device,
In the arithmetic processing unit, predetermined data is written to, read from, and written to a microcomputer that executes a program, a random access memory for data storage, a read-only memory for program storage, and a random access memory. When a read / write check program that compares read data with read data is provided and the read / write check results are output to an external device, the exclusive logic is used for the read / write check result data and the inverted data. Perform a sum (EOR) operation to determine true (1) / false (0), and in the case of negative (0), provide a program that outputs an error to the external device, exclusive with read / write check Abnormal output to external equipment with added blind spot detection by logical sum operation, protection / control arithmetic processing, and external equipment An operation command output respectively to an electrical angle of 30 ° is obtained by multiplexing processed in time division in one time.
[0010]
By doing so, the arithmetic processing unit of the digital protection / control device performs the protection / control arithmetic processing, outputs the operation command to the external device, the read / write check of the random access memory, and the read / write. After the exclusive OR operation of the check result, the output to the external device is executed once in each time division at an electrical angle of 30 °, and the microcomputer performs a read / write check on the random access memory in a single process. A certain amount of areas are sequentially applied to all areas to detect faults. If the read / write check result is abnormal, an error is output to the external device. Then, an exclusive OR operation is performed on the result of the read / write check and the data obtained by inverting the result, and if the determination is false (0), an abnormality is output to the external device. In this case, even when the area for storing the result of the read / write check is a failure, the external device can be notified that an abnormality has occurred.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a digital control / protection device of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 shows a block diagram of the present invention. In the figure, reference numeral 100 denotes a digital protection control unit. This digital protection control unit 100 is connected to a host computer 101 having a communication function corresponding to a host system via a communication network 102, and is protected and controlled by the digital protection control unit 100. The external device 103 controlled by the calculation result is notified.
[0013]
The digital protection control unit 100 includes an input transformer 1b that converts voltage and current signals from the power system 1a to be protected / controlled to an electronic circuit level (within ± 10V), converts an analog input signal into a digital signal, An analog input unit 1c for performing digital filter computation, a display 1d, a human interface unit 1e for setting protection and control computation set values and set values in a conversational manner with humans, and a modem capable of being connected to the communication network 102 Network interface unit 1f for performing the interface, network cable 1g for connecting the communication network 102 to the digital protection / control device, protection / control sequence calculation, data for the digital input unit 1i, digital output unit 1j Protection / control sequence calculation for transfer 1h, a protection / control sequence arithmetic unit 1h, an analog input unit 1c, a network interface unit 1f, a digital input unit 1i, a digital output unit 1j, and a system bus 1k for bus connection with a human interface unit 1e. Yes.
[0014]
FIG. 2 is a block diagram showing an internal configuration of the above-described protection / control sequence arithmetic unit 1h.
[0015]
In the figure, reference numeral 2a denotes a microcomputer for executing a protection / control operation program and a read / write check. This microcomputer 2a includes means 2b for executing analog input data in accordance with a protection / control operation algorithm, all of the random access memory. Read / write check 2c that reads and writes predetermined data in the area and checks that the data match, exclusive OR operation of read / write check result data and inverted data of read / write check result Means 2d for outputting the result of the protection / control operation to an external device via a system interface and a digital output unit, and connected to the system bus 2m. 2f is a system bus interface, 2g is a read-only memory for storing a protection / control operation program and a read / write check program for operating the microcomputer 2a, and 2h is a random access memory, both of which are system bus 2m Connected to.
[0016]
The random access memory 2h described above stores the data area 2i for storing the result of the read / write check 2c, the data area 2j for storing the inverted data of the result of the read / write check 2c, and the analog input data used for the protection / control calculation. An area 2k for storing data and an area 2l for storing protection / control calculation results are included.
[0017]
Next, the signal flow of the circuit in the protection / control sequence arithmetic unit 1h shown in FIG. 2 is shown.
[0018]
The microcomputer 2a executes the protection control calculation 2b using the analog input data 2k, which is a voltage / current signal taken from the power system, and outputs the result to the area 2l for storing the protection / control calculation result.
[0019]
The microcomputer 2a writes and reads predetermined data to and from the random access memory 2h, performs a read / write check 2c that compares the written data with the read data, and inverts the result and the result. When outputting the data and the result of the protection / control operation to the outside, the exclusive OR (EOR) operation is executed on the result data of the read / write check and the inverted data, and true (1) ) ・ Determines false (0), and outputs an error to an external device if negative (0).
[0020]
FIG. 3 shows a processing flowchart of the read / write check 2c.
[0021]
As shown in the figure, when the read / write check process is started, the address of the area to be checked in the random access memory is acquired (step 3a). Next, the data stored in the memory in the check area is saved (step 3b), predetermined data (code) for checking is written (step 3c), and the data in the same area is read (step 3c). Step 3d). Next, compare whether the written data (code) matches the read data (3e). If they match, the random access memory is judged as normal (3f), and if not matched, it is judged as abnormal (3g). Then, the saved data is restored, the address is updated to the area to be checked next time (steps 3h and 3i), and the check result and the inverted data of the result are written in different areas of the random access memory (step 3j, 3k).
[0022]
This read / write check 2c is carried out for every predetermined area in order at once for all areas. In the predetermined data (code), for example, 55 and AA are alternately used, and the failure is monitored in units of bits on both 0 and 1 sides.
[0023]
FIG. 4 shows a processing flow of exclusive OR operation.
[0024]
When the exclusive OR operation is activated, it is determined whether the result of the read / write check is abnormal (step 4a). If there is an abnormality, an abnormality alarm is output to the digital output unit (step 4d). Next, an exclusive OR (EOR) operation (step 4b) is performed on the result data of the read / write check and the data obtained by inverting the result to determine true (1) / false (0). If the determination is (0), an abnormality is output to the external device (step 4d).
[0025]
When it is confirmed that there is no abnormality in the result of the read / write check and the exclusive OR is true (1), the abnormality alarm output is restored (step 4c).
[0026]
FIG. 5A and FIG. 5B show examples of determination of exclusive OR processing. As shown in FIG. 5A, it is judged as true (1) when the two data are different, and as false (0) when they are the same as shown in FIG. 5B. And if there is no problem in the memory, the exclusive OR will not be false (0), so if a false (0) result is output, the memory will be missing or an abnormal charge will occur. You will be able to know what you did.
[0027]
FIG. 6 shows the situation of the time division multiplex processing of the microcomputer.
[0028]
As shown in the figure, the microcomputer has a data input process (1), a failure monitoring process (2) such as a read / write check, a protection / control calculation process (3), a sequence control process (4), a device control command and Abnormal alarm output processing is performed in the order of (5), once at an electrical angle of 30 °.
[0029]
FIG. 7 and FIG. 8 specifically show the processing of the exclusive OR operation by the block configuration diagram.
[0030]
In FIG. 7, since the read / write operation result of the random access memory 2d is abnormal (1), abnormal output is performed to the outside via the system bus interface 2b and the output circuit 6a of the digital output unit 1j. In this case, it indicates that a failure has occurred in the memory other than the area for storing the result of the read / write check.
[0031]
In FIG. 8, since the result of the read / write operation of the random access memory 2d and the result of exclusive OR of the inverted data are false (0), the system bus interface 2b and the output circuit 6a of the digital output unit 1j are used. Execute abnormal output to the outside. In this case, a failure has occurred in the memory area storing the result of the read / write check or the inverted data. Further, the microcomputer 2a separately determines the read / write check result signal and the exclusive OR result signal of the memory area storing the inverted data, so that an abnormality has occurred due to the read / write check, or Thus, it becomes possible to check whether a failure has occurred in the memory area for storing the inverted data.
[0032]
FIG. 9 shows a block configuration of calculation processing for calculation protection control when a one-chip microcomputer incorporating a random access memory and a read-only memory is applied.
[0033]
The embodiment shown in FIG. 2 is mainly different in that a one-chip type microcomputer incorporating a random access memory and a read-only memory is applied. In the embodiment of FIG. 2, the microcomputer monitors the failure of the random access memory connected via the bus. However, in the embodiment of FIG. 9, the microcomputer monitors the failure of the random access memory built in the microcomputer. Even in a system to which such a one-chip microcomputer is applied, measurement data and the like are obtained by performing an exclusive OR operation on the read / write operation result of the random access memory and the inverted data. It is possible to confirm whether or not a failure has occurred in the memory area used for this processing and the memory area in which the inverted data and non-inverted data are stored.
[0034]
【The invention's effect】
According to the present invention described above, it is possible to detect an abnormality including a monitoring result storage area, which is a blind spot of failure monitoring of a random access memory, and as a result, digital protection can be performed while the failure of the random access memory is inherent. -There is no case where the control unit is operated, and there is an effect that there is no malfunction or malfunction for power system protection and control.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a digital control / protection device of the present invention.
FIG. 2 is a block diagram showing protection / control sequence calculation in one embodiment of the present invention.
FIG. 3 is a flowchart showing a read / write check process in an embodiment of the present invention;
FIG. 4 is a flowchart showing exclusive OR operation processing in an embodiment of the present invention.
FIGS. 5A and 5B are diagrams illustrating an example of determination of exclusive OR processing in an embodiment of the present invention. FIGS.
FIG. 6 is a diagram showing microcomputer time division multiplexing processing in an embodiment of the present invention.
FIG. 7 is a block diagram showing a specific example of exclusive OR operation processing in one embodiment of the present invention.
FIG. 8 is a block diagram showing a specific example of exclusive OR operation processing in one embodiment of the present invention.
FIG. 9 is a block diagram showing an application example to a one-chip microcomputer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1a ... Power system, 1b ... Input transformer, 1c ... Analog input unit, 1d ... Display, 1e ... Human interface unit, 1f ... Network human interface unit, 1g ... Network cable, 1h ... Protection and control sequence arithmetic unit DESCRIPTION OF SYMBOLS 1i ... Digital input unit, 1j ... Digital output unit, 1k ... System bus, 2a ... Microcomputer, 2f ... System bus interface, 2g ... Read-only memory, 2h ... Random access memory.

Claims (4)

Analog input means for taking in voltage / current signals from the electric power system, digital input means for taking in external device information, and an arithmetic processing section for executing a predetermined arithmetic program on input data to the analog input means, A digital control / protection device comprising a digital output unit for outputting a calculation result of the calculation processing unit and a communication connection means for connecting to a communication network, executing a process according to a predetermined protection / control calculation and issuing an operation command to an external device In
Random access memory for storing the analog input data and operation result data of the arithmetic processing unit, and writing / reading predetermined data to the random access memory, comparing whether the data match , and checking results and monitoring means for storing the inverted data of the result in the random access memory, monitoring the mismatch by performing an exclusive OR operation with the inverted data of the monitoring result data of the monitoring result data and said monitoring means of said monitoring means A digital control / protection device comprising: means; and means for outputting a monitoring result of the means for monitoring the mismatch to an external device.   2. The digital control / protection apparatus according to claim 1, wherein a microcomputer incorporating the random access memory is used as an arithmetic processing unit. Analog input means for taking in voltage / current signals from the electric power system, digital input means for taking in external device information, and an arithmetic processing section for executing a predetermined arithmetic program on input data to the analog input means, A digital control / protection device comprising a digital output unit for outputting a calculation result of the calculation processing unit and a communication connection means for connecting to a communication network, executing a process according to a predetermined protection / control calculation and issuing an operation command to an external device In
Random access memory for storing the analog input data and operation result data of the arithmetic processing unit, and writing / reading predetermined data to the random access memory, comparing whether the data match , and checking The monitoring means for storing the result and the inverted data of the result in the random access memory, and performing the exclusive OR operation on the monitoring result data of the monitoring means and the inverted data of the monitoring result data of the monitoring means to monitor the mismatch Means for resetting the arithmetic unit when a failure occurs in the random access memory, means for confirming failure recovery after restart, and means for outputting a monitoring result to an external device when recovery fails. A digital control / protection device comprising:   4. The digital control / protection apparatus according to claim 3, wherein a microcomputer incorporating the random access memory is used as an arithmetic processing unit.

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