JPS60207414A - Protecting relaying device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Materials and Technology of the Invention] The present invention relates to a protective relay device having a constant monitoring function to detect malfunction of the device.

[Technical background of the invention and its problems]

In general, in order to improve the reliability of protective relay devices, multiplexing is used to systematically reduce the probability of malfunction or malfunction, and automatic monitoring to proactively detect malfunction or malfunction is often adopted. ing. There are various methods for multiplexing, but the two commonly used are internal direction detection relays that respond only when an accident occurs in the protected object, and internal direction detection relays that respond in case of an accident not only in the protected object but also in the system. This is a so-called series duplex system that is composed of detection relays and outputs a trip command only when both operate together.

This is intended to prevent malfunctions of the system due to defects in the internal direction detection relay.

In addition, by using relays with different operations for these two relays, for example, from the input CT of the internal direction detection relay,
If the input of the accident detection relay is taken from PT, C
It is possible to prevent malfunction even when T is defective.

Next, let's talk about automatic monitoring. Automatic monitoring is carried out with the aim of further improving the operational reliability due to the duplication described above. In other words, automatic monitoring is necessary for periodic inspections such as extending the periodic inspection cycle and shortening the inspection time, as the number of relays installed has increased due to the expansion of power systems and the multiplexing of relay devices, and in particular, the number of complex relays that require many maintenance items. The aim is to save labor in particular. The specific methods for this automatic monitoring include a constant monitoring method that detects malfunctions in relays that should normally be inactive, and an automatic method that applies an input equivalent to that at the time of an accident to the relay at regular intervals to check whether it is operating or not. It is classified into inspection method.

The former constant monitoring method constantly monitors the final output of a relay that should not operate at all times, and if it operates, it is regarded as abnormal and detected. However, in the event of a system fault, the system naturally operates up to the final output, so in order to differentiate from this, failure detection through constant monitoring must last longer than the operation duration at the time of the system fault, so a timer is installed to ensure that the system continues to operate for a certain period of time. It is determined to be defective only if In addition, automatic inspections trip-lock the device at one-step intervals and apply a simulated input to the relay that is different from when it is in good condition to determine whether it is working properly or not, making it possible to detect malfunctions of the disconnector before it occurs. It is.

If a faulty relay is detected through automatic monitoring, an external display and alarm is issued, but at the same time, the device is generally locked. This device lock is effective in preventing the relay from tripping due to an external accident during constant monitoring to detect failure due to malfunction.

FIGS. 1 and 2 show an example of an apparatus employing the above-described series duplication method and constant monitoring method. FIG. 1 is a system diagram in which a protective relay device for power transmission lines is installed. In the figure, reference numeral 10 denotes a power transmission line, which is connected to the A-terminal bus IA and the B-terminal bus IB. 2A and 2B are current transformers, 4A and 4B are potential transformers, and internal direction detection relays 11A and IIB, respectively.
and connected to accident detection relays 21A and 21B. Note that %3A and 3B are circuit breakers.

FIG. 2 shows a protective relay device constituted by the relay of FIG. 1. Further, FIG. 2 shows the device on the large end side, and a similar device is installed on the B@ side as well. In the figure, 31A is a timer that constantly detects monitoring failure.
110A is the normally open contact of 11 internal directional relays in Figure 1, 2
10A is a normally open contact of the fault detection relay 21A shown in FIG. Also, 41A is a manually operated changeover switch that is a contact that is normally closed when the device is in use. 31
0 person is a normally closed contact of the constant monitoring failure detection timer 31A. Bus lines P and N each indicate a control power supply line.

The response of this device will be explained with reference to FIGS. 1 and 2. When an internal accident occurs at F□ in Figure 1, the internal direction relay 11A and the accident detection relay 21A operate, and the second
Each normally open contact 110A, 210A shown in the figure closes. The AND circuit T in FIG. 2 is a trip circuit, and as mentioned above, the contacts 310 and 41A are always closed.
Since the contacts 110A and 210A close due to the occurrence of an internal accident, a trip command is established and a trip command output is issued to the breaker. Figure 1F. , JA, the accident detection relay 21A operates, but the internal direction relay 11A does not operate, and therefore does not trip. Next, we will discuss what to do when a relay malfunctions due to a defect. For example, the first
If the internal directional relay 11A shown in the figure malfunctions under normal conditions and the contact 110A shown in FIG.
It is locked by opening the normally closed contact 310A of A. Since the relays are duplicated in this way, a trip command will not be issued if only the internal direction relay 11A malfunctions. For this reason, the constant monitoring failure detection timer 31A
The operation time limit may be longer than the relay operation duration at the time of a system fault.

In general, when a defect is detected during constant monitoring, the trip lock is automatically activated as described above, and in order to investigate the defective location, one person manually operates the use/non-use selection switch 41 of the device, and the trip command circuit is activated. lock. Further, this changeover switch 41A is operated during periodic inspections or inspection work of off-panel equipment, etc., and is used to manually select whether to use or not use the device.

Conventionally, during periodic inspections or inspection work of equipment outside the panel, etc., the changeover switch 41A may be operated once and carried out in a trip lock state, and normally in this case, the constant monitoring failure detection circuit is locked. Constant monitoring failure detection timer 3 in Figure 2
This is why the changeover switch 41A is connected to 1A, and the contact 110A and 210
This is to prevent a defect detection operation from occurring every time a person performs an operation. Thereafter, when the inspection work is completed and the device is operated, the trip lock is released by operating the changeover switch 41A again, and the lock of the constant monitoring failure detection circuit is also released to restore the normal state.

However, during restoration, stress from testing is added to the parts,
If the equipment enters into operation with the relay malfunctioning due to a defective part or other cause, the failure detection operation will be performed after a certain period of time set in the constant monitoring failure detection timer after the recovery operation. The device will wake up and become trip-locked. In this case, in the conventional system, for example, if the internal directional relay 11A in FIG. 1 malfunctions, the contact 110A in FIG. 2 closes. Next, the constant monitoring failure detection timer 31A operates and the first
When an accident occurs at FOUT outside end A in the figure, the accident detection relay 21A operates, so the contact 210A in FIG. 2 closes and the trip command condition is established. Therefore, a mistake) IJ
Tsubu (: A serious problem occurs.

[Object of the Invention] In the present invention, when a device is restored from a locked state during periodic inspection or inspection of external equipment to an operating state after the work is completed, the relay malfunctions at the time of restoration until the trip lock is completed. An object of the present invention is to provide a protective relay device having a function of preventing mistrips when an external accident occurs.

[Summary of the invention]

In order to achieve such an object, the present invention provides a relay installed in a power system, a constant monitoring failure detection timer for this relay, a disconnection unit for connecting and disconnecting this relay and constant monitoring failure detection timer, Said successor? A protective relay device comprising a trip command circuit that automatically enters a locked state when a defect in the switch is detected and when the changeover switch is disconnected,
After the changeover switch is connected, the locking state of the trip command circuit is released after a certain time period set by the constant monitoring failure detection timer via an auxiliary relay that works with a limited time operation timer. shall be.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIG.

The same reference numerals as in FIG. 2 are given to the same parts. In the figure, a limited-time operation timer 51A driven by a changeover switch 41A, an auxiliary relay 61A driven by a normally open contact 510A of the limited-time operation timer 51A are inserted, and a normally open contact 610 of the auxiliary relay 61A issues a trip command. inserted into the circuit. In such a configuration, when the contact of the changeover switch 41A is manually opened, the time-limited operation timer 51A is reset, and when the auxiliary relay 61A returns, the contact 610 of the trip command circuit returns, causing the trip lock state 1 to return. When you close this four-door power switch AIk, the time-limited operation timer 5LA starts. At this time, if the contacts 110A of the 11 internal directional relays are closed due to malfunction, the constant monitoring failure detection timer 31A is also activated at the same time.

Note that cooperation may be achieved by making the time limit of the time-limited operation timer 51A longer than that of the constant monitoring failure detection timer 31A. If both timers are not activated, the trip circuit is locked by the contact 610A, and even if the contact of the fault detection relay 21A closes due to an external accident at this time, a mistrip will not occur. As described above, the contact 110 continues to operate, and the constant monitoring failure timer 31A operates earlier than the limited time operation timer 51A, so the trip command circuit is locked by the contact 310A. After that, the time-limited operation timer 51A operates and the contact 61 of the auxiliary relay 61A
Even if 0A is closed, the trip command circuit will continue to be locked and will not cause fJ failure. In addition, as another method, even if the device is not locked when a faulty monitoring is detected, only the trip lock is performed when the selector switch is manually turned off.
It is also possible to consider a method of canceling this trine-arrot curve on a fixed time edge.

〔Effect of the invention〕

As described above, according to the present invention, a protective relay can be used to prevent erroneous tripping in the event of an external accident, even if the relay is malfunctioning and outputting an erroneous output without manually restoring it from a hibernation state to an operating state. equipment can be provided.

[Brief explanation of the drawing]

Fig. 1 is a power transmission line system diagram in which a protective relay is installed, Fig. 2 is a circuit diagram of a conventional protective relay device, and Fig. 3 is a circuit diagram of a protective relay device according to an embodiment of the present invention. It is. 11A... Internal direction detection relay 41A... Changeover switch 21A... Accident detection relay 51A... Limited time operation timer 31A... Constant monitoring failure detection timer 61A
...Auxiliary relay 110A, 210A, 310A,
510A, 610A...Contact T...Trip command circuit Agent Patent attorney Kensuke Chika (and 1 other person) Fig. 1 Fig. 2 ρ LヱR1ko

Claims (1)

[Scope of Claims] 1. A relay installed in a system, a constant monitoring failure detection timer for this relay, a changeover switch for connecting and disconnecting this relay and the constant monitoring failure detection timer, and a switch that connects and disconnects this relay from the constant monitoring failure detection timer, and when a failure is detected in the relay. and a trip command circuit that automatically enters a locked state when the changeover switch is disconnected, wherein the connection edge of the changeover switch is configured to release the lock state of the trip command circuit by an auxiliary relay interlocking with a time-limited operation timer. A protective relay device characterized in that the continuous monitoring failure detection timer is configured to carry out the monitoring after a fixed time period set by the failure detection timer. 2. The set time of the time-limited operation timer is longer than the set time of the constant monitoring failure detection timer.
Protective relay device as described.