JPS5828545B2 - Synchronous verification circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synchronization verification circuit used for synchronously connecting AC circuits of different systems.

Conventionally, as this type of device, one shown in FIG. 1 has been used.

In the figure, 1a is the AC main circuit of system A, 1b is the AC main circuit of system B, 2a is an instrument transformer (hereinafter referred to as PO) connected to the AC main circuit of system A, and 2b is an instrument transformer connected to the AC main circuit of system A. System B
Connect to the AC main circuit of: PT, 3a is the circuit protection fuse connected to BT of system A, 3b is the circuit protection fuse connected to FT of system B, 4 is the synchronization verification circuit breaker, and 5 is the synchronization verification indicator. , 6 is a synchronization verification indicator light, 7, 7 is a voltmeter, 8. a is a frequency meter, 9 is a synchronous verification circuit bus, 9R is a reference bus in the synchronous verification circuit bus 9, 9S is a combined bus in the synchronous verification circuit bus, and 9E is a ground bus in the synchronous verification circuit bus 9. , 10 is a breaker connected between the AC main circuits of systems A and B.

According to the above-mentioned conventional synchronous verification circuit, the currents of different systems,
The voltages are P and T2a provided in the system A AC main circuit 1a and the system B AC main circuit 1b, respectively.

2b is led to the synchronization verification circuit bus 9 through the synchronization verification circuit switch 4 of the protection fuses 3a and 3b, and the ground sides of RT are both connected to the ground bus 9E of the synchronization verification circuit bus 9, and the system A BT, is connected to the reference bus 9R, and PO of system B is connected to the additional bus 9S.

Now, when the synchronization verification circuit switch 4 is turned on, the voltmeters 7, 7 and the frequency meters 8, 8 indicate the circuit status of each system, and the synchronization indicator 5 indicates the above-mentioned A.

B, voltage phase difference between two systems on the reference side (for example, A system side)
Indicates whether another system (for example, system B) is "advanced" or "lags" in comparison with the current system.

In addition, the indicator light 6 connected between the reference bus 9R and the combined bus 9S is turned on by the cross current of the synchronization verification circuit bus 9 when a voltage difference or phase difference occurs between the A and B systems. .

Therefore, when turning on the circuit breaker to the AC main circuits 1a and Ib of both the A and 8 systems, the power source of the other system (for example, the B system) is turned off so that the voltage and frequency are equal to the voltage and frequency of the reference side (for example, the A system). The voltage and frequency of both systems A and B must be adjusted by operation.

However, at this time, even if the voltages and frequencies of both systems match, if the phases are out of sync, the synchronization indicator 5 will indicate the phase difference.
The indicator light 6 does not stop at the "0" position, and the amount of light increases as the phase difference increases.

However, if the above conditions become the same phase, the phase difference of the synchronization indicator 5 becomes "0" and the indicator light 6 also turns off, so the AC main circuits of systems A and H are connected via the breaker 10. Can be connected.

Further, after the circuit breaker 10 is turned on, the synchronization verification circuit switch 10 is normally turned off to stop the operation of the synchronization verification circuit.

Since the conventional synchronous verification circuit is configured as described above, for example, when one of the opposing AC circuits of both systems is not charged, when the circuit is configured with the synchronous verification circuit switch 4 turned on. If the AC circuit on the charging side is the A system, then the A system AC main circuit 1a is connected to BT, 2a, the reference bus 9R1 indicator light 6, the additional bus 98. )? A circuit for charging the B system AC main circuit 1b is configured through T and 2b.

As a result, the AC main circuits of both systems 1 a t 1 b are charged with the breaker 10 in the "off" state, and the current capacity to charge the AC main circuits 1 a t 1 b of both systems is determined. In some cases, there were defects that could cause the protective fuse to break, or cause electric shock during inspection or adjustment.

The present invention has been made in order to eliminate the drawbacks of the conventional ones as described above, and even when a synchronous verification circuit is configured when one of the AC main circuits is not charging, it is possible to prevent charging from the synchronous verification circuit to the main circuit. The aim is to provide a circuit that can prevent this.

An embodiment of the present invention will be described below with reference to FIG. 2. In the figure, 11 is a winding of a voltage detection electromagnetic relay provided between the reference bus 9R and the ground bus 9E, 11a is a contact of the relay,
12 is a coil of a voltage detection electromagnetic relay provided between the merging bus 9S and the ground bus 9E, 12a is a contact of the relay 12, and all other symbols are the same as in FIG. 1.

According to the above configuration, first, as a circuit verification means, the synchronization verification circuit switch 4 is closed to configure a synchronization verification circuit, and if both AC main circuits ia and lb are charged, PT, 2a
, 2b, the circuit protection fuse 3 a y 3 b, and the synchronization verification circuit switch 4 to charge the synchronization verification circuit bus 9 .

As a result, the voltage detection electromagnetic relay windings 11 and 12 are both excited, and the contacts 11a and 11b of the relays 11 and 12 are
are both closed to form the six indicator light circuits of the synchronization verification circuit, and the synchronization verification circuit becomes operational.

Next, when the AC main circuit 1a of system A is charging and the AC main circuit 1b of system B is not charging, the synchronous verification circuit switch 4
When the system A AC main circuit 1a is closed, P, T,
2a, circuit protection fuse 3a, synchronization verification circuit breaker 4
Although the reference bus 9R is charged via the system B AC main circuit 1b, the additional bus 9S is not charged because the system B AC main circuit 1b is not charged.

At this time, the voltage detection electromagnetic relay winding 11 on the reference bus 9R side is excited and its contacts 11a are closed, but the voltage detection electromagnetic relay winding 12 on the combined bus 9S side is not excited and its contacts 12a is open, and the indicator light 6 of the synchronization verification circuit
No circuit is configured.

Therefore, there is no need to reverse charge the non-charging AC main circuit 1b via the circuit of the indicator light 6.

Note that one end of the voltmeter 7 and frequency meter 8 is connected to the ground bus 9E.
It is clear that reverse charging from this circuit is impossible.

Further, the synchronization verification method is exactly the same as the conventional example described above.

In the above embodiment, the case where there is one indicator light 6 is shown, but
There may be a plurality of indicators, and it is also possible to use other indicating instruments.

Further, the voltage detection electromagnetic relay may be provided in the AC main circuit, and as long as its contacts 11a and 12a are located in series with the indicator lamp 6, there is no particular order.

Furthermore, it goes without saying that the same effect can be obtained even if the voltage detection electromagnetic relay is replaced with another semiconductor element or the like.

As described above, according to the present invention, by providing an electromagnetic relay for voltage detection in the synchronization verification circuit and inserting its contact between the AC main circuits of both systems, reverse charging is prevented, making it inexpensive and safe. This has the effect of making it possible to construct circuits.

[Brief explanation of drawings]

FIG. 1 is a conventional synchronization verification circuit diagram, and FIG. 2 is a synchronization verification circuit diagram showing an embodiment of the present invention. In the drawings, the same reference numerals indicate the same or corresponding parts. 1a: System A AC main circuit, 1b: System B AC main circuit, 2
a: System A AC circuit instrument transformer, 2b: System B AC circuit instrument transformer, 3a: System A circuit protection fuse, 3b
: System B circuit protection fuse, 4: Synchronous verification circuit switch,
5: Synchronization verification indicator, 6: Synchronization verification indicator light, 7: Voltmeter, 8: Frequency meter, 9: Synchronization verification circuit bus, 9R: Reference bus in the synchronization verification circuit 9, 9S: Synchronization verification circuit 9
9E: Ground bus in the synchronization verification circuit 9, 10: Breaker, 11: Electromagnetic relay for detecting voltage on the 9R bus side, 11a: Electromagnetic relay electrical connection for detecting voltage on the 9R bus side. , 12: Electromagnetic relay for detecting the voltage on the 9s bus side,
12a: Electromagnetic relay connection for detecting the voltage on the bus side of the 9s bus.

Claims (1)

[Claims] 1. A comparative test by connecting a plurality of alternating current circuits of different systems through voltage transformers and switches, respectively, and transferring electric quantities such as frequency, voltage, and phase between the alternating current circuits. In the synchronization verification circuit, a relay element is provided between each synchronization verification circuit bus bar of this synchronization verification circuit, and an indicator and each contact of each of the above relay elements are connected in series between each positive polarity phase. Synchronous verification circuit. 2. The synchronization verification circuit according to claim 1, wherein the relay element is provided between the reference bus, the combined bus, and the ground bus of the synchronization verification circuit.