JPH02111218A - Digital protection relay device - Google Patents

Abstract

PURPOSE:To effectively prevent an erroneous operation even if an undefinite output is generated due to the calculating malfunction of a main detection relay by allowing a fail-safe relay to inspect only when the main detection relay normally runs and the fail-safe relay receives an automatic inspection command. CONSTITUTION:When the calculating function of a main detection relay 1 malfunctions due to the runaway of a CPU 3, the CPU 3 does not normally process a programming. Accordingly, running monitor processing means 30 generates no output, normal running discriminating means 31 output a signal of logic '0' with no output of the means 30, and condition discriminating means 33 stops outputting an automatic inspection enable signal.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) This invention has a main detection relay that locks a trip circuit during an automatic inspection, and also generates an automatic inspection command. The present invention relates to a digital protection relay device in which the safe relay inspects the final stage output relay.

(Prior Art) In an electric power system, if a protective relay device malfunctions, it will have a large effect, and in the worst case, it may lead to system collapse, so it is important to improve operational reliability.

Malfunctions in protective relay devices can be categorized based on their effects and countermeasures: (a) malfunctions that do not operate when they should, and malfunctions that operate when they should not.

Analog protection relay devices are generally equipped with a constant monitoring function whose main purpose is to discover malfunctions and an automatic inspection function whose main purpose is to discover malfunctions and malfunctions.These two functions are collectively referred to as This is called the automatic monitoring function.

FIG. 2 is a block diagram showing the configuration of this analog protection relay device. In the figure, the normally closed trip lock contact 22 of the automatic monitoring circuit 21, the normally open output contact 24 of the main detection relay 23, and the normally open output contact 26 of the failsafe relay 25 are connected to the trip circuit. There is. The automatic monitoring circuit 21 detects malfunctions of the main detection relay 23 or its contacts 24 and the failsafe relay 2.
5 or its contact 26, and opens the normally closed contact 22 for trip lock during automatic inspection, main detection relay 23 and failsafe relay 25.
It is equipped with an automatic inspection function that issues inspection commands and confirms the results.

Here, in the automatic inspection, a method is adopted in which the automatic monitoring circuit 21 sequentially gives commands to the main detection relay 23 and the fail-safe relay 25 to confirm the operation and recovery of the contacts 24 and 26. For analog protection relay devices, this is
This is because each relay hardware unit is independent for each element and purpose.

Further, the automatic monitoring circuit 21 is constituted by hardware different from the main detection relay 23 and the fail-safe relay 25, and the amount of hardware dedicated to automatic monitoring accounts for 25 to 30% of the entire protective relay device.

On the other hand, in the case of digital protection relay devices, the measures to improve reliability are the same as those adopted for analog types, but since the arithmetic processing section includes a microprocessor, its arithmetic processing function is It differs from the analog type in that it is possible to use self-diagnosis technology to check the health of most of the hardware that makes up the relay device.

In other words, the digital protection relay device achieves a function that has the same purpose as the automatic monitoring function that has been adopted in the analog protection relay device, but mainly uses a self-diagnosis method.

FIG. 3 is a block diagram showing the configuration of this type of digital protection relay device. This includes a main detection relay 1 and a fail-safe relay 2, which are constructed from mutually different hardware. Among these, the main detection relay 1 is composed of a CPU 3 that performs relay calculation processing and automatic monitoring processing, and an output circuit 4 that outputs the processing results (14), and controls the opening and closing of the final stage output relay contacts 8 based on the calculation processing results. function,
A function that opens the final stage output relay contact 8 and opens the normally closed contact 7 for trip lock by forced operation output during automatic inspection to perform automatic inspection processing of the main detection relay, and sends an inspection command V to the fail-safe relay 2. It has the ability to give. The fail-safe relay 2 mainly includes a CPU 5 that performs relay processing arithmetic processing, and an output circuit 6 that outputs the processing results, and has a function of controlling the opening and closing of the final stage output relay contact 9 based on the arithmetic processing results. , and has a function of closing the final stage output relay contact 9 by forced operation output according to the inspection command V during automatic inspection.

(Problems to be Solved by the Invention) In the conventional digital protection relay device described above, the main detection relay 1 and the fail-safe relay 2 are connected through automatic inspection control.
If a malfunction or the like occurs in the arithmetic function of the PU 3, an unexpected situation may occur.

In other words, if runaway occurs in the CPU 3 due to a defect in the arithmetic function, it will not be able to perform the predetermined operation according to the program, causing an undefined output to the output circuit 4, and at the same time issuing an undefined inspection command to the fail-safe relay 2. Sometimes.

As an example, if an inspection command is given to the fail-safe relay 2 without outputting a command to open the normally closed contact 7 for trip lock, the CPU 5 of the fail-safe relay 2 will force the output circuit 6 to operate in response to this inspection command. An output is generated and the final stage output relay contact 9 is closed. As a result, both the trip lock contact 7 and the final stage output relay contacts 8 and 9 were closed, causing malfunction of the digital protection relay device, which in the worst case could lead to the collapse of the power system.

This invention has been made to solve the above problems, and provides a digital protection relay device that can reliably prevent malfunction even when an unstable output is produced due to a malfunction in the calculation function of the main detection relay. With the goal.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides: a travel monitor processing means for monitoring the travel of the main detection relay; normal running determination means for determining whether or not an automatic inspection command has been applied to the fail-safe relay; The present invention is characterized by comprising condition determining means that enables inspection of the fail-safe relay on the condition that it is determined that a command has been received.

(Function) In this invention, the fail-safe relay can be inspected only when the main detection relay runs normally and the fail-safe relay receives an automatic inspection command. If a malfunction occurs in the arithmetic function of the main detection relay, it goes without saying that the fail-safe relay cannot be inspected, thereby preventing malfunctions caused by a malfunction in the arithmetic function of the main detection relay.

(Embodiment) FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In this figure, the same reference numerals as in FIG. 3 indicate the same or corresponding parts. Further, a running monitor processing means 30 for monitoring normal running is added to the CPU 3 constituting the main detection relay 1, and a running monitor processing means 30 is added to the CPU 5 constituting the fail-safe relay 2 based on the output of the running monitor processing means 30. Normal running determination means 31 for determining whether or not the vehicle has traveled normally;
Conditions that enable automatic inspection when the inspection command confirmation means 32 confirms whether or not the PU 3 has issued an inspection command, and the normal running determination means 31 determines that the vehicle is running normally, and the inspection command confirmation means 32 confirms the inspection command. The feature of the present invention is that a discriminating means 33 is added.

The operation of this embodiment configured as described above will be explained below.

First, the main detection relay 1 performs the above relay calculation process,
The final stage output relay contact 8 is opened during normal operation, the trip lock contact 7 is opened during automatic inspection, and an inspection command V is given to the fail-safe relay 2. During these processes, the running monitor processing means 30 performs the following checks. Execute.

a. Monitoring using a watchdog timer A clear signal is output from the CPU 3 to an external hard timer at regular intervals to monitor whether the program has stopped or run out of control.

b. Known Fixed Program Calculation Check Execute calculations using a known fixed program and check whether a predetermined calculation result is obtained.

C. Checks whether there is an undefined instruction other than the bit configuration defined as an invalid check instruction word.

d. Parity check When reading data in the CPU 3, it is determined whether the memory data and redundant bits are in a predetermined format.

e. Compare the total sum of data in the entire checksum program memory area with known data.

f. Read/Write Check Data Write predetermined data in the entire memory area and read it.

Regarding these checks, please refer to "Electricity Cooperative Research"
Since it is shown in Volume 14, No. 4, detailed explanation thereof will be omitted.

Next, the CPU 5 constituting the fail-safe relay 2 controls opening and closing of the final stage output relay contact 9 according to the arithmetic processing described above. Further, the normal running determination means 31 provided in the CPU 5 reads the output of the monitor processing means 30 and outputs the output from the CPU 5.
3 is running normally or abnormally, and outputs an rHJ signal when it is running normally.

In addition, the inspection command confirmation means 32 provided in the CPU 5 is
It is determined whether or not the inspection command V is received from U3, and when the inspection command ■ is received, a signal of logic "1" is output. moreover,
The condition determining means 33 outputs a signal that enables automatic inspection when both the normal running determining means 31 and the inspection command confirming means 32 output a signal of logic "1", that is, when the AND condition is satisfied.

Here, as a specific example, the calculation function of the main detection relay 1 is C
The operation when the PU3 becomes defective due to runaway will be described below.

When the arithmetic function is malfunctioning, the CPU 3 does not perform the programmed normal processing, so the driving monitor processing means 30 does not generate any output, and the driving is normal? The 111 means 31 outputs a logic "0" signal when there is no output from the running monitor processing means 30, and prevents the condition determining means 33 from outputting a signal that allows automatic inspection.

In addition, as another specific example, the CPU 3 goes out of control and outputs the closing signal of the final stage output relay contact 8 without outputting the opening signal of the trip lock contact 7 to the output circuit 4, and furthermore, the fail-safe relay The operation when the inspection signal V is applied to the circuit 2 will be described below.

In this case, both the trip lock contact 7 and the final stage output relay contact 8 are closed. In addition, in the fail-safe relay 2, the normal running determination means 31
By the running judgment processing by the inspection command confirmation means 32 and the inspection command processing by the inspection command confirmation means 32, the condition discrimination means 33 tries to generate a forced operation output when a signal of logic "1" is output in both cases, but the normal running judgment means 31 tries to generate a forced operation output. Information from CPU3
Since this is a runaway, the output of the normal running determining means 31 is suppressed to the logic rOJ. Therefore, the AND of the condition determining means 33
If the condition is not met, a forced operation output is generated for automatic inspection, and the final stage output relay contact 9 remains open.

Thus, even if both the trip lock contact 7 and the final stage output relay contact 8 are closed, if the final stage output relay contact 9 remains open, the digital protection relay device will not malfunction. do not have.

Note that, after that, when the runaway mode of the CPU 3 of the main detection relay 1 changes and the inspection command V is restored (no longer output), both the inspection command confirmation means 32 and the normal running determination means 31 are set to the logic rOJ. Since the last stage output relay contact 9 remains open, the digital protection relay device will not malfunction.

Thus, according to this embodiment, even if an unstable output is produced due to a malfunction in the arithmetic function of the main detection relay, malfunction can be reliably prevented.

Note that the driving monitor processing means 30, the normal driving determining means 31, the inspection command confirming means 32, and the condition determining means 33 in this embodiment can all be realized by a CPU program, so there is no need to add hardware, and the configuration is simple. You will get a digital protection relay device.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, there is provided a running monitor processing means for monitoring the running of the main detection relay, and whether or not the main detection relay has run normally based on the output of the running monitor processing means. normal running determination means for determining whether or not an automatic inspection command has been applied to the fail-safe relay; Since the relay is equipped with a condition determination means that enables the inspection of the direct ratio fail-safe relay on the condition that it is determined that the inspection command has been received, the inspection command is indefinitely sent to the fail-safe relay due to a malfunction in the calculation function of the main detection relay. This has the effect of being able to reliably prevent malfunctions even in such cases.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.
FIG. 2 is a block diagram showing the configuration of an analog protection relay device, and FIG. 3 is a block diagram showing the configuration of a conventional digital relay device. 1... Main detection relay, 2... Fail safe relay 3.5... CPU, 4.6... Output circuit, 7...
Trip lock contact, 8.9... Final stage output relay contact, 30... Driving monitor processing function, 31... Normal running judgment function, 32... Inspection command confirmation function, 33...
・Condition discrimination function. Tagani's agent Yu Sato Figure 1

Claims (1)

[Claims] In a digital protection relay device in which the main detection relay locks the trip circuit during automatic inspection and also generates an automatic inspection command, and the fail-safe relay inspects the final stage output relay based on this automatic inspection command, the main detection relay a running monitor processing means for monitoring running; a normal running determining means for determining whether or not the main detection relay has run normally based on the output of the running monitor processing means; inspection command confirmation means for determining whether or not the inspection command has been applied; A digital protection relay device comprising a condition determining means that enables inspection of a safe relay.