JPH04127819A - Protective relay - Google Patents

Abstract

PURPOSE:To shorten the recovery time at failure occurrence by putting, as locking condition, the operation command of main detection relay output in the detection circuit for the breaking monitoring of a tripping circuit, and not making the failure when the relay output has malfunctioned the wire breakage failure of the tripping circuit but making it the output circuit failure. CONSTITUTION:When a monitoring current does not flow to PC116a and the response signal of PC116a becomes zero, the output of a NOT circuit 216a becomes '1'. At this time, if a relay operation command 211a is nonoperation, the output of the NOT circuit 215a becomes '1', and starts a tripping circuit wire breakage detection timer 219, and when it continues above time limit, it judges the tripping circuit failure, and outputs a relay operation command too so as to operate a relay 213a. Next, a main relay operation output relay 113a closes the path, and a monitoring current flows to 113a, and ceases to flow to PC116a. At this time, the response signal 214a of PC 116a becomes '0', and the NOT circuit 216a becomes '1', but the NOT circuit 215a becomes '0', and the output of an AND circuit 217a remains '0'. Therefore, the timer 219 is not started, and it does not judges the tripping circuit failure.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides a trip circuit for each phase that is configured with a plurality of relay outputs that operate for each fault phase in the event of an internal fault within a protection zone. This invention relates to a protective relay device that monitors disconnection of disconnection circuits and output circuits.

(Prior Art) A conventional monitoring method will be explained using circuits shown in FIGS. 2 and 3.

Figure 3 shows relay outputs that operate in the event of an accident regardless of the protection zone or phase of the accident (hereinafter referred to as fail-safe relay outputs), and relay outputs that operate only in the event of an internal accident within the protection zone, regardless of the phase of the accident. This is a three-phase collective trip circuit consisting of a relay output (hereinafter referred to as the main detection relay output). Figure 2 shows a three-phase collective trip circuit consisting of multiple relay outputs that operate for each fault phase in the event of an internal fault within the protection zone. This is a trip circuit for each phase.

First, the three-phase collective trip configuration shown in FIG. 3 will be explained.

In Figure 3, there is a relay output 311 that locks the tripping circuit during inspection, a fail-safe relay output 312, a main detection relay 313, and a photocoupler that detects whether the relay output is output based on the presence or absence of voltage between the terminals of each relay. (Hereafter referred to as PC, the response signal of the photo power plastic is "1" when there is voltage, and "O" when there is no voltage.) is sent to relay output 311, PC 314, and relay output 312. 315 PCs are provided for the relay output, and 316 PCs are provided for the relay output 313.

Also, test terminals 317 for voltage confirmation of trip locks and trip circuits, terminal block 318 indicating the output terminal of this protective relay device, 319 indicating the cable from this protective relay device to the shaft, L, and disconnector. Terminal block 32 showing input terminals
0, a breaker tripping coil 321, and a breaker auxiliary contact 322.

Here, the operation of the circuit shown in FIG. 3 will be explained.

First, when the protective relay device plans to trip the breaker and outputs relay outputs 312 and 313, the relay output 311, which locks the trip circuit during inspection, closes the trip circuit during non-inspection, so the breaker In the turned-on state, the auxiliary contact 322 is closed, so the connection between the control power supplies P and N is closed, and the breaker trip coil 32
A tripping current flows through 1. At this time, the breaker is tripped, opening its auxiliary contact 322 and cutting off the trip current.

By the way, even though the protective relay device is intended to trip the breaker, if it is only able to trip due to the cause of the failure shown below, the accident will not be eliminated and serious damage may occur to the power system. In order to detect defects, disconnection of trip circuits or output circuits are monitored.

During disconnection monitoring of the trip circuit, the following defects were detected.

- Forgetting to tighten the test terminal 317 - Disconnection of the breaker tripping coil 321 - Disconnection of the breaker auxiliary contact 322 - 0 disconnections Disconnection of the cable 319 from the protective relay device to the breaker In order to detect these defects, A very small monitoring current that does not cause the breaker tripping coil 321 to operate is constantly flowing through the trip circuit. This monitoring current flows to PCs 315 and 316 connected in parallel to the relay outputs 312 and 313 when there is no disconnection failure in the tripping circuit and the relay outputs of the caps 312 and 313 are not output. At this time, the response signal of the PC is "i".

However, even though the auxiliary contact 322 of the breaker is closed, the response signals of both PCs 315 and 316 are 0.
゛ are the defective items 1 to 4 above or 312 and 3.
This is a case where all 13 relay outputs are output. In other words, when both PCs 315 and 316 continue to be 0, 32
6, the output of the N07 circuit of 327 becomes 1, the condition of the ND circuit of 325 is satisfied, and after the failure detection timer of 329 elapses, an alarm is issued as a disconnection failure of the tripping circuit.

At this time, the timer 328 is activated via the OR circuit 324, and an alarm is also issued for an output circuit failure after the timer expires.

Next, the output circuit monitoring detected the following defects.

■Malfunction of relay output 311 that locks the removal circuit for inspection ■Malfunction of relay output 312 ■Malfunction of relay output 313 As described above, each relay output 311, 3123
13 terminals connected in parallel 314, 315, 316
This is detected based on the response signal of PC.

In normal conditions, there is no relay output, so the response signal of PC314 is 0'' (The trip circuit is closed during non-inspection, so the monitoring current flows through the relay output side with low impedance.) The response signals of PC315 and 316 are ° The signal is inverted by the NOT circuit at 326 and 327 to become 0.

However, the response signal of PC314 is "1" even though the breaker is turned on as in the case of trip circuit disconnection monitoring.
Also, when the response signals from the PCs 315 and 316 continue to be "0", it is determined that the above-mentioned defective items 1 to 3 have occurred, and the timer 32 is sent via the OR circuit M@324.
When the timer reaches 8, an alarm will be issued.

However, it is rare for two or more of the output malfunctions described in items 1 to 3 above to occur at the same time, and usually only one of them operates. Therefore, the condition of the AND circuit 325 is not satisfied and only the output circuit failure is detected.

As mentioned above, in the case of the three-phase collective trip circuit shown in Figure 3,
It is possible to distinguish between a trip circuit disconnection failure and an output circuit failure.

Next, the configuration of each phase trip shown in FIG. 2 will be explained.

In Fig. 2, a relay output 111 for opening/closing the tripping circuit during inspection, a fail-safe relay output 112,
Main detection relay outputs 113a, 113b, 113c that operate in response to fault phases (R, S, T), test terminals 117a, 117b, 117c corresponding to each phase
, a terminal block 118a indicating the output terminal of the protective relay device,
118b, 118c, 119a, 119b, 119c showing the cable from this protective relay device to the breaker
, terminal blocks 120a, 120 indicating input terminals of the breaker
b, 120c, a tripping coil 121a corresponding to each phase because the breaker to be tripped is different for each phase;

121b, 121c, and its auxiliary contact 122a,
122b, 122c, a PC 114 that detects whether the relay output is output based on the presence or absence of voltage between the relay output terminals.
, 115, 116a, 116b, and 116c.

Next, the output circuit monitoring detected the following defects.

■ Malfunction of relay output 111 that locks the circuit during inspection ■ Malfunction of relay output 112 ■ Malfunction of relay outputs 113a to 113C As described above, each relay output 111, 112113a to 11
114, 115, 116a connected in parallel to 3C
It is detected by the PC response signal of ~116C.

Normally, the PC response signal is 11 because the relay output is not output.
4 '0'' (Since the trip circuit is closed during non-inspection, the monitoring current flows through the relay output side with small impedance.), p of 115, 116a to 116c
The response 'signal of c is "1", so 123
, 124a to 124C invert the signal and detect it.

However, 114, 115, although the circuit breaker is closed in the same way as in the three-phase collective trip circuit.

When the response signal from PC 116a to 116c continues to be "0", it means that the above-mentioned faulty items 1 to 3 have occurred, so the OR circuit 125 is established and an alarm is issued after the fault detection timer 128 expires. put out.

Next, the case of disconnection of the tripping circuit will be explained.

During disconnection monitoring of the trip circuit, the following defects were detected.

■Forgetting to tighten test terminals 117a to 117C ■L of breaker coils 121a to 121C! Ii line■ 0 contact failures of breaker auxiliary contacts 122a to 122b Cable breakage from the protective relay device to the breaker In order to detect these failures, a small monitoring current that does not operate in the breaker disconnection coils 121a to 121C is constantly flowing to the trip circuit. This monitoring current is determined to be 112a to 112C and 112a to 112C and 1
When none of the relay outputs 13a to 113C are output, the current flows through the PCs 115 and 116a to 116C connected in parallel to the relay outputs 112 and 113a to 113c. At this time, the response signal of the PC is "1".

However, even though the auxiliary contacts 122a to 122C of the circuit breaker are closed, 115 and 116a to 116C
The reason why the operating output of all PCs becomes '0°' is from 1 to 1 above.
The defective parts of each Japanese umbrella in 4 are 112a and 313a to 313.
This is the case when all outputs of C are output together.

However, if only one phase out of the three phases of the tripping circuit is defective, for example, when the R phase is defective, the output of PC116a is 0"'
However, PC116b and 116c in healthy S and T phases
remains at "1".Also, since the S and T phases are healthy, the monitoring current also flows to PC115, so the output remains at "1".For this reason, the output remains at "1". If only the P is defective, as in the three-phase collective trip circuit shown in Fig.
It is only possible to monitor disconnection of the tripping circuit if the conditions of the AND circuit of C115 and PC116a to 116b are satisfied.

As described above, detection is possible only when all three phases of the tripping circuit are defective, so it is not very effective in practice, and it is often not possible to distinguish between a disconnection failure in the tripping circuit and a failure in the output circuit.

(The problem to be solved by the invention! M) As mentioned above, in the case of the conventional trip circuit for each phase, it is not possible to distinguish between trip circuit disconnection monitoring and output circuit monitoring, so whether the output circuit of the protective device is defective or the trip circuit is defective. The limitation of
Because the faulty parts were not removed until they were determined through on-site inspections, it took a very long time to restore the system, and during that time, lines were stopped or backups were needed, which caused major operational problems.

The present invention has been made in view of the above circumstances, and provides protection that can easily distinguish between disconnection of the trip circuit and output circuit failure, and shorten the recovery time after failure by limiting the cause of the failure. The purpose is to provide a relay device.

"Structure of the Invention" (Means and Effects for Solving the Problems) The present invention provides an operation command for the main detection relay output as a lock condition to a detection circuit for monitoring disconnection of the trip circuit, thereby preventing the relay output from malfunctioning. The failure in this case is not a disconnection failure in the tripping circuit, but a failure in the output circuit. In other words, if the response signal of the PC connected in parallel to the relay output is 0'' and an operation command for the main detection relay output is issued, disconnection monitoring of the tripping circuit is locked and only the output circuit is defective. This makes it possible to limit the causes of defects.

(Example) Examples will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of an embodiment of a monitoring circuit applied to a protective relay device according to the present invention.

In FIG. 1, 211a, 211b, and 211c are relay operation commands that operate in response to the accident phase when an accident occurs within the protection zone, and are relay driver outputs 212a, 211c, respectively.
12b.

Relays 213a, 213b, 21 via 212C
Drive 3c.

214a, 214b, and 214c are the PCs shown in FIG.
116a, 116b.

The response signal of 116C is always “1°” when the monitoring current is flowing through the PC. Relay driver 212
a.

The outputs of 212b and 212c are always "o" and are inverted by NOT circuits 215a, 215b and 215c, respectively, and the response signals 214a and 214 are always "1".
The outputs of b and 214c are always “i” and are NOT circuit 2.
16a, 216b, 216c and always "
o ”.This NOT circuit is connected to
AND circuits 217a and 217b are a combination of C.

Enter 217C.

For example, if the monitoring current does not flow to the PC 116a in FIG.
When the response signal of C116a becomes "o", the output of NOT circuit 216a becomes 1'. At this time, if the relay operation command 211a is inactive, the relay driver 212a becomes 0°, and the output of the NOT circuit 215a becomes 1°. For this reason, the output of the ND circuit 217a becomes '1', and the output is passed through the OR circuit 218 to the trip circuit disconnection detection timer 21.
Start 9.

If the activation continues for more than the time limit of the timer 219, it is determined that the tripping circuit 222 is defective. The above is PC116b, 116
Similarly, in the case of C, AND circuits 217b and 217c are used, respectively.
This starts the timer 219 and determines that the tripping circuit is defective. Here, a relay operation command 211a is output, and the relay 213a operates via the relay driver 212a.

The response when the relay operates will be explained.

When 213a operates, the main relay operation output relay 113a in FIG. 2 closes, so the monitoring current flows to 113a,
It stops flowing to the PC 116a (because the PC 116a has a high resistance, most of the monitoring current flows to the small resistance 113a). At this time, the response signal 214a of the PC 116a becomes 0'' and the NOT circuit 216a becomes ``1''. Since the output of the relay driver 212a is 1'°, the NOT circuit 215a becomes '0', and the output of the AND circuit 217a remains at 'o'.

Therefore, the timer 219 is not activated, and it is not determined that the tripping circuit is defective.

The above explained 211a, but 211b, 21
1c as well, the relay operation commands 211b and 211c cause the outputs of the NOT circuits 215b and 215c to become "0'', so the outputs of the AND circuits 217b and 217c become "0''.
o'', the timer 219 is not started, and it is not determined that the tripping circuit is defective.In addition, the NOT circuit 216a,
Since 216b and 216c become "1", timer 221 is started via OR circuit 220, so timer 2
After the time limit of 21, it is determined that the output circuit of 223 is defective.

Relay output 111 in Figure 2 is always closed and P
When C114 becomes 1 and the relay output is always in operation, it becomes P.
When C115 becomes '0', it is inverted by the NOT circuit 217 and becomes 1, and the timer 2 is sent to 0 through the circuit 220.
21 is activated, and after the time limit, the output circuit of 223 becomes defective.

According to the above embodiment, when the trip circuit is defective, the monitoring current does not flow to the PC monitoring the trip circuit, and it is determined that the trip circuit is disconnected and the output circuit is defective, but the relay operation command is If it does not exist, it is determined that there is only a defect in the output circuit, so the defective part can be easily determined.

[Effects of the Invention] Since it is not possible to distinguish between a defective conventional disconnection circuit and an output circuit only by displaying the defect, it takes a lot of time to limit the defective part. In other words, a disconnection failure in the trip circuit is caused by a cable disconnection or forgetting to tighten the test terminal, etc., and an output circuit failure is a failure of the contact used in the trip circuit that is constantly operating, so it is a failure on the equipment side. . Since the contents of the defect are different in this way, the recovery response will be different. For this reason, up until now, we had to conduct an on-site investigation and determine which type of defect was occurring before taking any action. 1. During this period, there was a huge disruption to operations, such as line outages or reliance on backup protection.

However, according to the present invention, it is possible to determine whether the trip circuit is defective or the output circuit is defective, making it easier to respond when a defect occurs and shortening the recovery time of the device.
It becomes possible to reduce problems in system operation.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of a monitoring circuit applied to a protective relay device according to the present invention, FIG.
The figure is a configuration diagram of a three-phase collective trip circuit. 211a, 211b, 211cm...Movement command 21
2a, 212b, 212cm...driver circuit 2
14a, 214b, 214cmPC response signal 21
7b, 217c/AND circuit 220...OR circuit 221...Failure detection timer...Tripping circuit failure...Output circuit failure 17a 218.

Claims (1)

[Claims] The first system that operates in the event of an accident regardless of the protection zone or accident phase.
In a protective relay device having a trip circuit configured by a logical product condition of a relay output and a second relay output that operates for each fault phase when a fault occurs within the protection zone, the operation of the second relay output is If a command is input as a lock condition to the detection circuit for monitoring disconnection of the tripping circuit and the relay output malfunctions, it will be determined as an output circuit failure, and if an operation command for the second relay output is issued, it will be determined as a disconnection. A protective relay device characterized by locking monitoring and determining an output circuit failure.