JPS60240015A - Device for inspecting breaker tripping circuit - 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 [Technical Field of the Invention] The present invention relates to a breaker trip circuit inspection device using a thyristor.

[Conventional technology]

Traditionally, trip circuits for circuit breakers have typically been constructed using electromagnetic relay contacts, and trip circuits using thyristors have rarely been implemented; By configuring the thyristor switching circuit as in the example shown in the figure, it can be applied to a breaker trip circuit.

Since a DC power source is normally used as the power source for the breaker trip circuit, the basic circuit generally controls the gate current as shown in FIG. 4 of the above-mentioned magazine P94. Further, while the voltage and current of the breaker trip circuit are relatively large, the voltage and current of the thyristor 4 gate control circuit are small, and it is necessary to insulate the two circuits from each other for surge protection and the like.

A conventional thyristor trip circuit inspection device to which the above basic consolidation is applied will be explained with reference to FIG.

Terminal 1 is a signal input terminal for switching the first thyristor (hereinafter referred to as the first input terminal), and terminal 2 is a signal input terminal for switching the second thyristor (hereinafter referred to as the second input terminal).
Terminal 3 is a signal input terminal (hereinafter referred to as a first inspection input terminal) for switching the first thyristor for inspection.

Terminal 4 is a signal input terminal for switching the second thyristor for inspection (hereinafter referred to as the second inspection input terminal);
-1.5-2 is a thyristor firing control circuit (hereinafter referred to as a control circuit) that converts continuous input into intermittent pulses and controls the firing of the thyristor gate input; 6-1.6-2 is a pulse input The above control circuit 5-1.5-2 and the post-input circuit 8-1.8-2 are pulse transformers that respond differentially at
A coupling circuit is constructed that couples the signals using pressure-insulated signals. 8-1.8-2 is a gate input circuit (hereinafter referred to as input circuit) that adjusts the thyristor gate input and protects it from malfunctioning due to surges, etc. This input circuit, the control circuit, and the coupling circuit perform thyristor switching. It constitutes a circuit. 9-1.9-2 is a thyristor, 10-1.
10-2 is a protection circuit that prevents thyristor 9-1.9-2 from malfunctioning or being destroyed by surge input, and when the thyristor switches, the potential between the anode and cathode becomes close to zero, so this potential drop is detected. A thyristor protection/operation detection circuit (hereinafter referred to as thyristor protection/operation detection circuit) is equipped with an operation detection circuit that recognizes thyristor operation by detecting thyristor operation, and a high impedance resistor (not shown) connected between the anode and cathode. ), 11 is the trip coil of the breaker, and the above thyristor 9-1.9
-2 is connected in series to form a breaker trip circuit. lla is a pallet contact that opens when the breaker operates, 12 is a trip lock contact that opens when checking the operation of the thyristor, 13 is an OR circuit, and 15 is a high impedance resistor connected in parallel with the trip lock contact 12. .

Next, the operation will be explained. The trip lock contact 12 and pallet contact 11a are normally closed, and when both thyristors 9-1 and 9-2 turn on, the breaker trip coil 11 is energized, and when the breaker operates, the pallet contact 11a is opened. do. That is, the breaker trip circuit is duplicated with thyristors 9-1 and 9-2, and is configured to prevent the thyristor from operating due to an abnormality in itself or the thyristor switching circuit. The conditions for operating 11 are:
This is the case only when there are inputs to both the first and second input terminals 1.2.

Pulse transformer 6-1.6-2 is thyristor 9-1.9
It insulates the high voltage circuit on the -2 side and the low voltage circuit on the input terminals 1 and 2, and its output response is differential. Therefore, in the control circuit 5-1 and 5-2, the input terminals 1 to 5-2
The continuous DC input coming in from 1.4 is made into an intermittent pulse signal, and an appropriate pulse signal extension circuit is added to the input circuit 8-1.8-2. Even if there is a difference in the input application times of the second input terminals 1.2, the gate input application times of the thyristors 9-1, 9-2 are controlled so that they overlap, or they are output at the same timing.

This ensures that two thyristors are operated.

Note that when both thyristors 9-1 and 9-2 are turned on, a current that is restricted by the impedance of the breaker trip coil 11 flows.1 Normally, this current value is larger than the holding current of the thyristor, so the pallet contact 11a is opened. The current continues to flow until

In order to inspect a thyristor trip circuit having a defective structure as described above, conventionally, before applying a single inspection input, the trip lock contact 12 is opened for the purpose of preventing malfunction. This release eliminates the short circuit in the resistor 15, and the high impedance resistor (included in the operation detection circuit) connected between the anode and cathode of the thyristor 9-1.9-2 applies a voltage between the anode and cathode. A voltage is applied to the trip coil of the circuit breaker through the series circuit of the resistor 15 and the resistor 15, but the current flowing through this trip coil is extremely small and does not operate the pallet contact 11a. In this state.

Applying an inspection input to the first or second inspection input terminal 3.4 or based on inspection manual input to the first or second inspection input terminal 3.4. Second input terminal 1.
2, each of the thyristors 9-1, 9-2 is operated individually, this operation is detected by the operation detection circuit 10-1, 10-2, and the detection signal is output via the OR circuit 13 for confirmation. Was.

The conventional circuit breaker trip circuit inspection device is constructed as described above, and prevents malfunction during one inspection using the auxiliary relay contact for trip lock (contact 12 in the illustrated example), so it can be used as a complete static trip circuit. However, major drawbacks were problems such as surges generated by the auxiliary relay coil housed within the device and poor contact at the contacts.

[Summary of the invention]

This invention was made to eliminate the above-mentioned drawbacks of the conventional system, and the inspection input/output circuits provided in the thyristor coupling circuit are connected in reverse to each other.

The purpose of the present invention is to provide an inspection device that can inspect a breaker trip circuit without trip locking by contacts by locking the other thyristor at the same time when inspecting the operation of a thyristor to be inspected. There is.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to FIG. 2, in which the same parts as in FIG. 1 are denoted by the same reference numerals.

In FIG. 2, reference numeral 7 denotes a limiting resistor, and 14-1, 14-2 denotes a determining element for operating the thyristors 9-1, 9-2, respectively, which can be operated or forcibly locked upon receiving a 1-inspection signal. The operation of the pulse transformer 6-1, 6-2 is the same as the conventional one, but it has a separate tertiary coil for inspection, and the limiting resistor 7 and the pulse transformer 6-1, 6-2
(7) Tertiary: A closed circuit is formed with the lil. In the figure, primary and secondary.

The side marked with an X on the tertiary coil indicates the winding start side of the coil, and the input/output polarity relationship is depolarization.

Next, the operation of an embodiment of the present invention having the above configuration will be described. When checking the operation of the thyristor 9-1, an operation signal is applied to the first inspection input terminal 3 of the determination element 14-1, and at the same time a lock signal is applied to the first inspection input terminal 3 of the determination element 14-2. An operation signal is output to the first input terminal 1, and the output to the second input terminal 2 is locked.

In addition, when checking the operation of the thyristor 9-2, an operation signal is applied to the second inspection input terminal 4 of the determination element 14-2, and the operation signal is output to the second input terminal 2, contrary to the above. Output to the first input terminal is locked.

The operation when inspecting the thyristor 9-1 will be described below.

When an input is applied to the first input terminal 1, the control circuit 5-1 operates so that a positive output is output to the primary coil winding start side (coded as Xn pieces) of the pulse transformer 6-1, and the pulse transformer Outputs are generated at the winding start sides (Xn pieces) of the secondary and tertiary coils 6-1.

This secondary coil output is the thyristor gate input circuit 8-
1 to the gate of the thyristor 9-1 in the operating direction, and since the tertiary coil output is input from the end of the tertiary coil winding of the pulse transformer 6-2 via the limiting resistor 7, the pulse The signal is output from the winding end side to the secondary coil of the transformer 6-2, and is applied as a non-operating direction input to the gate of the thyristor 9-2 via the thyristor gate input circuit 8-2.

Therefore, when thyristor 9-1 operates, thyristor 9-2 is locked at the same time. Similarly, when checking the operation of thyristor 9-2, thyristor 9-1 is locked.

Note that when inspecting the operation of the thyristor, for example when thyristor 9-1 is operating, a high impedance resistor (included in thyristor protection/detection circuit 10-2) that applies voltage between the anode and cathode of thyristor 9-2 is used. ), and when thyristor 9-2 is operating, the anode of thyristor 9-1
A high impedance resistor (
This is because voltage is applied to the trip coil 11 via the thyristor protection/detection circuit 10-1).

The current flowing through the trip coil is very small and does not actuate the pallet contacts.

Next, a case will be described in which inputs are applied to the first input terminal 1 and the second input terminal 2 during normal times when all inspections have not been performed. In this case, since it is an internal accident, thyristor 9-1
．． 9-2 act together to cause the breaker trip coil 11 to receive enough current to operate all of the pallet contacts. In this case, the output generated at the positive pole side (coil winding start side) of the tertiary coil of the pulse transformer 6-1, 6-2 is circulated through the limiting resistor 7, but due to the size of the limiting resistor 7 and the thyristor gate input. If the input impedance of circuits 8-1 and 8-2 is set appropriately, the gate input of thyretors 9-1 and 9-2 can be secured sufficiently, and a pulse transformer tertiary coil can be added for one inspection. However, there will be no problem.

Note that when checking the operation of the thyristor 9-1 or 9-2 by applying a check input to the 1 check input terminal 3 or 4, the input is not applied to the terminals 1 and 2 at the same time.
．． If the two signals are cross-locked, there will be no malfunction during the first inspection.

In other words, in this invention, this cross lock is determined by the determination element 14.
-1.14-2 is used.

The operation signal of determination element 14-1 is the lock signal of determination element 14-2, and the operation signal of determination element 14-2 is determination element 1.
By using the lock signal 4-1, the danger of simultaneous operations is prevented.

In the above embodiment, circuit insulation is provided by the pulse transformers 6-1 and 6-2, but an optical element such as a photocoupler is used instead of the pulse transformer.
- Operation direction output to thyristor gate circuit 8-1.8-2 with optical element output replaced with secondary coil output of 1.6-2 and thyristor 8-1 with optical element output replaced with tertiary coil output
．． If this is cross-connected as the non-operating direction output to 8-2 and the operating direction output is set to be thicker than the non-operating direction output, the same effect as the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, the inspection input/output circuits provided in the thyristor coupling circuit are connected in reverse to each other, and when the operation of the thyristor to be inspected is inspected, the other thyristor is simultaneously locked. Therefore, the breaker trip circuit and the entire thyristor control circuit can be inspected without installing a trip lock contact in the breaker trip circuit, and there is no need to worry about contact malfunction or contact failure. This has the effect of making the completely stationary trip circuit inspection device simple and inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a principle circuit diagram showing a conventional breaker trip circuit inspection device, and FIG. 2 is a principle circuit diagram showing a breaker trip circuit inspection device according to an embodiment of the present invention. 5-1.5-2...Ignition control circuit, 6-1.6-2°
°°Pulse transformer, 8-1.8-2...gate input circuit, 9-1.9-2...thyristor. 10-1.10-2... Thyristor protection/operation detection circuit, 11... Breaker trip coil. Note that in Figure 5, the same reference numerals indicate the same or equivalent parts. Figure 1

Claims (1)

[Claims] A breaker trip circuit in which a plurality of thyristors and trip coils of the breaker are connected in series, a protection/operation detection circuit that detects a drop in the voltage between the anode and cathode of each of the thyristors, and a gate input circuit of each of the thyristors. and a thyristor switching circuit comprising an ignition control circuit and a coupling circuit that couples both circuits with mutually insulated signals; A breaker trip circuit comprising: an input/output circuit for inspection, which is provided separately and independently for each, and is configured to lock the other thyristor at the same time when the operation of the thyristor to be inspected is inspected by connecting the thyristors with opposite polarities to each other; inspection equipment.