JP4140465B2 - Operation check method of digital protective relay device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital protective relay device, and more particularly to an operation inspection system for a trip circuit using a digital input / output circuit (DIO) and an auxiliary relay.
[0002]
[Prior art]
3A shows a block configuration of the digital protection relay device, and FIG. 3B shows an automatic monitoring range thereof (see, for example, Non-Patent Document 1).
[0003]
This digital protection relay device is composed of a main detection (M) relay unit 1 and an accident detection (FS) relay unit 2, and these configurations are represented by the voltage V V of the protection target system as shown by the relay unit 1. And current I with a filter to remove harmonic components, hold them after sampling with a sample and hold circuit, take them in a time division manner with a multiplexer, and sequentially convert them into digital values with an A / D converter. Capture to the CPU via the bus.
[0004]
The CPU connects the A / D converter, memory, settling value memory, DI circuit, and DO circuit on the system bus, performs protection operation based on the sampled V and I data, and when protection operation is required A trip signal is generated from the DO circuit.
[0005]
The trip circuit 3 generates a trip command on the condition that the trip signals (M, FS) of both the main detection relay unit 1 and the accident detection relay unit 2 are simultaneously output, and further confirms that the trip lock (11T) is not performed. A trip command is generated on condition.
[0006]
The automatic monitoring shown in (b) of FIG. 3 performs analog input data monitoring, A / D converter accuracy monitoring, settling value monitoring, CPU monitoring, memory monitoring, and DIO monitoring for continuous monitoring, and inspection monitoring. Check analog input circuit and DIO / trip circuit.
[0007]
Here, in the inspection of the DIO trip circuit which is a part of the automatic inspection in the digital protective relay device,
(1) The auxiliary relay of the trip circuit 3 is driven by the digital output from the DO circuit,
(2) Import the auxiliary relay contact answer from the DI circuit,
(3) Check whether the operation of the digital input / output circuit and the auxiliary relay is normal by determining ON / OFF of the contact answer.
[0008]
FIG. 4 shows an inspection time chart, and the monitoring span (clock) is determined by the processing capacity of the CPU, but is usually synchronized with the sampling time of analog data for checking the analog input circuit.
[0009]
In the figure, when an inspection start command is generated, a trip lock is performed from a trip lock start command to a trip lock end command. During this lock period, the analog input circuit inspection and the DIO / trip circuit are inspected as the main detection relay in the first half. Inspect and confirm trip relay operation and return as trip relay DI answer. In the second half of the lock period, check the accident detection relay.
[0010]
[Non-Patent Document 1]
Electric cooperative research, Vol. 50, No. 1, published by Electric cooperative research group [0011]
[Problems to be solved by the invention]
As described above, the DIO / trip circuit inspection method, which is part of the automatic inspection in the digital protective relay device, has the following problems.
[0012]
(1) During the trip circuit inspection period, trips against system faults are locked, and the protective relay device is in an unprotected state. Moreover, as a protection method, the main detection relay (M) and the accident detection relay (FS) have two series, and an AND circuit forms a trip circuit, and the main detection and the accident detection are carried out with a time difference. . For this reason, the inspection time also becomes longer, and considering the operation / recovery time of the auxiliary relay, a lock time of 100 ms to several hundreds of ms is required, depending on the characteristics of the auxiliary relay, and the unprotected state against a system fault becomes longer. End up.
[0013]
(2) In order to force the auxiliary relay to operate, a circuit that locks in hardware is necessary so as not to cause an actual trip.
[0014]
(3) If the trip lock relay installed in (2) above is defective, inspection cannot be performed.
[0015]
(4) The contact signal for answering may be different from the auxiliary relay contact used for the trip circuit. In this case, the trip circuit may be judged to be abnormal even if it is normal. The reverse is also true.
[0016]
An object of the present invention is to provide a digital protection relay device that solves the above problems.
[0017]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention is based on the premise that the main detection relay and the accident detection relay are confirmed to operate with a time difference, and the inspection operation confirmation is completed before the circuit breaker operates after the auxiliary relay operates. A method of returning the auxiliary relay or a method of ending the check operation check before the operation of the auxiliary relay has the following configuration.
[0018]
(1) A trip circuit that connects the contact output of the auxiliary relay for trip output of the main detection relay and the contact output of the auxiliary relay for trip output of the accident detection relay to obtain the operation output of the circuit breaker is provided.
A trip signal of the main detection relay, which is constituted by a CPU and is output from the DO circuit to the trip circuit, is used as a drive signal for an auxiliary relay for trip output of the main detection relay, and a trip signal of the accident detection relay is output as a trip output of the accident detection relay. The operation check system of the digital protection relay device that checks the operation of the DO circuit, DI circuit, and trip circuit by taking the answer signal from the trip circuit side to the DI circuit as a drive signal for the auxiliary relay for the relay. There,
The operation check is performed after the check operation check is completed before the circuit breaker operates when both the trip output auxiliary relay of the main detection relay and the trip output auxiliary relay of the accident detection relay operate. A means for returning the relay is provided.
[0020]
If the auxiliary relay is faster, the monitoring span (clock) for checking the DI circuit and the DO circuit is 10 μsec to several 100 μsec in order to confirm the answer of the DI circuit before the auxiliary relay operates. It is preferable to start the task separately.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
FIG. 1 is an inspection flowchart of a DIO / trip circuit in a main detection relay or an accident detection relay according to an embodiment of the present invention, which has a software configuration of a CPU. Note that the block configuration of this embodiment is the same as that of FIG.
[0022]
In the DIO / trip circuit check phase (S1), when the DIO / trip circuit is checked on (S2), the on operation signal is set to the DO circuit output (S3), and whether there is an answer on signal input to the DI circuit. Is checked (S4). If an answer on signal is input in this check, the on check flag is set to ok (ON operation check) (S5), and the off check flag set and the DO circuit output to be the next phase are reset (S6).
[0023]
If no answer on signal is input, a time limit check of the operation confirmation timer is performed (S7), and the processes (S1) to (S4) are repeated until the time limit of the timer is reached. When the answer on signal is not input until the timer expires, the on check operation failure (ng) process is performed (S8), and the off check is entered (S6).
[0024]
Next, when an off check is performed by resetting the output of the DO circuit (S9), it is checked whether an answer off signal is input to the DI circuit (S10). If an answer off signal is input in this check, an off inspection flag is set to ok (OFF operation confirmation) (S11), a flag for the next inspection phase is set, and the inspection process is terminated.
[0025]
If no answer off signal is input, a time limit check of the operation confirmation timer is performed (S13), and the processes (S9) to (S10) are repeated until the time limit of the timer is reached. When the answer-off signal is not input until the timer expires, an off check operation failure (ng) process is performed (S14), and the next check phase is entered (S12).
[0026]
In the present embodiment, the auxiliary relay is operated in each process in the process flowchart of FIG. 1, but before the circuit breaker operates, the ON operation confirmation and the OFF operation confirmation are finished, and the auxiliary relay is returned. The reason why the above problem can be solved by realizing this confirmation operation will be described below.
[0027]
Recently, improvement in hardware technology has improved the processing capacity of the CPU, so that the processing span can be increased. Since the operation time of the auxiliary relay is about 1 ms to several tens of ms, the relay operates in the conventional span. Therefore, if the processing span is changed from several hundred ns to several tens of μs and the inspection is completed at high speed, the auxiliary relay operates. However, the circuit breaker will not trip.
[0028]
That is, in this embodiment, even if the auxiliary relay is operated, a certain amount of current capacity and time are required until the actual circuit breaker is driven. Assuming that the main detection and the accident detection are performed with a time difference, even if the auxiliary relay is operated, the operation check is completed before the circuit breaker operates, and the auxiliary relay is returned.
[0029]
As described above, generally, if the operation time of the auxiliary relay is about 1 ms to several tens of ms, it is sufficient to set the processing span from several hundred ns to several tens of μs. In this case, there is a possibility that the auxiliary relay operates during the inspection and trips in the span. In this case, an answer can be confirmed by separately starting a task of 10 μsec to several 100 μsec only at the time of inspection.
[0030]
As described above, in this embodiment, the ON operation confirmation and the OFF operation confirmation are performed from the time when the auxiliary relay operates until the circuit breaker actually operates. All the processes in FIG. 1 are completed within this period, and the timer period in the processes S7 and S13 is also set within the period.
[0031]
In order to actually operate the auxiliary relay, a trip lock circuit is necessary as a backup. However, the trip lock can be performed in a short time and is basically unnecessary.
[0032]
(Embodiment 2)
In the first embodiment, the auxiliary relay is operated, and the operation check is finished before the breaker operates. On the other hand, in this embodiment, the operation check is finished before the auxiliary relay operates.
[0033]
Specifically, as shown in FIG. 2, the DO circuit in FIG. 3 outputs a trip signal using a photocoupler for both the main detection relay and the accident detection relay, and the trip signal or signal amplification is performed. The auxiliary relay is driven.
[0034]
Here, in this embodiment, the output signals DIFS and DIM of the photocoupler are fed back as answer inputs as they are, without using the relay contact answer as the answer input of the DI circuit. Thereby, before the auxiliary relay operates by the trip signal output from the DO circuit, the answer on and off are confirmed, and the inspection is finished.
[0035]
In the present embodiment, the actual operation of the auxiliary relay cannot be confirmed as compared with the first embodiment, but the input / output of the drive signal of the DO circuit, the DI circuit, and the auxiliary relay can be confirmed. Since the auxiliary relay itself is not operated, a trip lock circuit is not required.
[0036]
【The invention's effect】
As described above, according to the present invention, on the premise that the main detection relay and the accident detection relay check the operation with a time difference, the check operation check is completed after the operation of the auxiliary relay and before the circuit breaker operates. Therefore, there are the following effects.
[0037]
(1) Since the inspection time of the DIO / trip circuit is greatly shortened, there is almost no time for the protective relay device to be in an unprotected state by trip lock against a system fault.
[0038]
(2) Since the inspection is finished before the trip circuit operation after or before the operation of the auxiliary relay, a hardware lock circuit for preventing an actual trip is unnecessary or simplified.
[0039]
(3) The trip lock relay can be inspected even if it is defective.
[0040]
(4) Even when the contact signal for answering is different from the auxiliary relay contact used for the trip circuit, the operation of the trip circuit can be confirmed.
[Brief description of the drawings]
FIG. 1 is an inspection process flowchart according to first and second embodiments of the present invention.
FIG. 2 shows an example of a trip circuit in Embodiment 2 of the present invention.
FIG. 3 is a diagram showing a digital protective relay device and an automatic monitoring range.
FIG. 4 is an inspection time chart of the digital protective relay device.
[Explanation of symbols]
1 ... Main detection relay unit 2 ... Accident detection relay unit 3 ... Trip circuit

Claims (1)

A trip circuit is provided to connect the contact output of the auxiliary relay for trip output of the main detection relay and the contact output of the auxiliary relay for trip output of the accident detection relay to obtain the operation output of the circuit breaker.
A trip signal of the main detection relay, which is constituted by a CPU and is output from the DO circuit to the trip circuit, is used as a drive signal for an auxiliary relay for trip output of the main detection relay, and a trip signal of the accident detection relay is output as a trip output of the accident detection relay. The operation check system of the digital protection relay device that checks the operation of the DO circuit, DI circuit, and trip circuit by taking the answer signal from the trip circuit side to the DI circuit as a drive signal for the auxiliary relay for the relay. There,
The operation check is performed after the check operation check is completed before the circuit breaker operates when both the trip output auxiliary relay of the main detection relay and the trip output auxiliary relay of the accident detection relay operate. An operation check method for a digital protective relay device, characterized by comprising means for returning a relay.

Images