JPH11205924A - switchboard - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To perform a power failure test of a partial load without causing a power failure of the entire plant even during plant operation. SOLUTION: A switch 3c provided for each load for performing a power failure test and provided in the middle of a cable connecting between the load and the power bus 6, and exciting coils 3a and 3b for electromagnetically turning on / off the switch. Circuit breaker 3, a switch 3c for controlling the energization of the coils 3a and 3b to open and close the switch 3c, and a switch 4 provided between the corresponding switch 4 and the corresponding circuit breaker 3 to cut off the switch 4. The test target selection switch 5 that controls the energization of the coils 3a and 3b of the circuit breaker 3 on the energization path that bypasses the switch 4 when the space between the switches 3 is released, and the energization path that bypasses the switch 4 by the switch 5 is selected And a power failure generating means for controlling the exciting current flowing through the current path to release the switch 3c and cut off the power supply to the load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power receiving and distribution system for a plant having a plurality of loads, and more particularly, to a continuous power failure test for a partial load without a continuous power failure or a momentary power failure even during plant operation, and a momentary power failure. The present invention relates to a switchboard capable of performing a test.

[0002]

2. Description of the Related Art In a plant having a plurality of loads, a continuous power failure test or an instantaneous power failure test of a partial load is required without stopping the entire plant even during plant operation.
FIG. 3 is a single-line diagram of a typical switchboard used for a power receiving and distributing facility of a plant. The switchboard includes an A-system switchboard and a B-system switchboard having different power receiving systems. The distribution board 1 of the A system includes motors A33, AA34,
C35, CC36 and other loads are connected,
Motors B37, BB38 and other loads are connected to the switchboard 1 of the B system.

[0003] These motors serve as electric loads for driving pumps provided corresponding to the motors. For example, three pumps provided in parallel in a water supply system or a condensate system are respectively connected to motors A33, B37, and A33. C35, and three pumps provided in parallel in the same system are driven by motors AA34, BB38, and CC36, respectively. The motors A33, AA34, C35, CC36,
It is assumed that the operation of B37 and BB38 is as follows.

Normally, two motors A33, C35 and B37 are operated and one is spare, and similarly, motors AA34, CC36 and B37 are used.
Normally, two B38s are operated and one B38 is used as a spare. However, the motor A33, C35, B
If one of the 37 or the motors AA34, CC36, and BB38 is operated by one unit or zero units, the other motor must also be operated by one unit or zero units. (The discharge capacity of the pumps in the parallel configuration needs to be the same).

Here, the motors A33, AA34, B3
7, when the power distribution board 1 of the B system is out of power while the BB 38 is operating, the motors C35 and CC36 should start automatically as a standby machine, but one of the motors C35 and CC36 does not start automatically due to a failure or the like. In such a case, the above operation causes the other once started motor to be automatically stopped again. In this state, when the power distribution board of the system B recovers from the power failure within a predetermined time thereafter, the motors B37 and BB38 are automatically started again so as to operate the two systems. For loads with complex interlocks as described above, not only check on the desk but also perform continuous power failure and instantaneous power failure tests, and check whether the behavior of each load is as expected in the design. It is necessary to check carefully. In addition, since the interlock is complicated as described above, in addition to those that clearly require a continuous power failure test and an instantaneous power failure test, there is a possibility that an interaction not expected in the design may occur between the loads, A continuous power failure test and an instantaneous power failure test for the entire plant are required.

Therefore, conventionally, a continuous power failure test and an instantaneous power failure test method are performed as follows. That is, conventionally, when a continuous power failure test is performed, for example, by turning off the on / off switch of the power receiving circuit breaker 31 during power reception of the switchboard of the A system in FIG. Check whether the behavior is as designed. Further, when performing the instantaneous power failure test of the plant, a test device for the instantaneous power failure test is manufactured and connected to the power receiving circuit breaker 31 during the test,
In response to the ON / OFF signal from the test device, the power receiving circuit breaker 31 during power receiving is cut off for a certain period of time assumed in the design, and it is confirmed whether the behavior of all loads in the plant is as designed.

[0007]

When the interlock of a part of the load is changed after the start of operation of the plant, it is necessary to repeat the continuous power failure test and the instantaneous power failure test of the load. However, the conventional test was configured to be performed only when the plant operation was stopped, such as during periodic plant inspections. An instantaneous power outage will occur, disturbing other loads that are not under test. Therefore, conventionally, when a continuous power failure test or an instantaneous power failure test is performed during plant operation, a test apparatus is manufactured for each individual load and the test is performed. Therefore, when the interlock of some loads is changed after the start of plant operation, only a continuous power failure test or an instantaneous power failure test can be performed for each load. There is a problem that can not be confirmed. In order to confirm the soundness of the interlock between each load, etc., it is conceivable to manually open and close multiple circuit breakers at the same time and perform a test. And it is practically difficult.

In particular, in a nuclear power plant, since the entire plant cannot be stopped for testing, there is a demand for a method for performing a reliable test by continuously or instantaneously interrupting a partial load. .

It is an object of the present invention to provide a switchboard which enables a continuous power failure test or an instantaneous power failure test of a partial load without a continuous power failure or an instantaneous power failure of the entire plant even during the operation of the plant.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a switch which is provided for each load to be subjected to a power failure test and which is provided in the middle of a cable connecting between the load and the power bus, and which electromagnetically connects the switch. A circuit breaker having an exciting coil for turning on / off, an on / off switch provided for the circuit breaker to control the energization of the exciting coil to open / close the switch, and a corresponding on / off switch and a corresponding cutoff A test object selection switch provided between the ON / OFF switch and the circuit breaker for controlling energization to an exciting coil of the circuit breaker through an energizing path bypassing the ON / OFF switch when the space between the ON / OFF switch and the circuit breaker is released; When the energizing path bypassing the on / off switch is selected by the test target selection switch, the exciting current flowing through the energizing path is controlled to release the switch for a set time and cut off the power supply to the load. Blackout When the energizing path bypassing the ON / OFF switch is selected by the test power outage generating means and / or the test object selecting switch, the exciting current flowing through the energizing path is controlled to continuously release the switch, and This is achieved by providing a power failure generating means for a continuous power failure test that interrupts power supply to the load.

With the above configuration, the power failure can be caused by the power failure generating means only for the load accommodated in the circuit breaker in which the test target selection switch has been turned on, without causing a power failure in the entire plant.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of a switchboard according to one embodiment of the present invention. The switchboard 1 shown in FIG. 1 is provided with a circuit breaker unit 2 for each load, which supplies three-phase AC power to a plant load and cuts off the supplied power.
The circuit breaker unit 2 includes a circuit breaker 3 and an on / off switch 4.
And a test target selection switch 5. Circuit breaker 3
An opening / closing section 3c provided in the middle of the three-phase wiring for connecting between the power supply bus 6 and the output cable 7 to the plant load, for opening and closing the three-phase wiring, and the opening / closing section 3c in the closed state are detached. And a closing coil 3a which closes the opening / closing section 3c which is in the open state. The on / off switch 4 includes an on / off switch 4a provided in the middle of the wiring for supplying the exciting current to the closing coil 3a, and an on / off switch 4b provided in the middle of the wiring for supplying the exciting current to the tripping coil 3b.

The test object selection switch 5 is provided in the present embodiment, and includes a connection between the switch 4a and the closing coil 3a and a connection between the switch 4b and the tripping coil 3a.
two switches 5 for simultaneously turning on and off the connection to
a-1 and 5a-2, and two switches 5b-1 and 5b-2 which are simultaneously turned on and off, wherein the switches 5a-1 and 5a-2 are turned off when turned on, and the switches 5a-1 and 5a-2 are turned off when turned off. Switch 5b- that turns on switches 5a-1 and 5a-2
1, 5b-2. The switches 5b-1 and 5b-2 are turned on when a load connected to the circuit breaker unit 2 is selected as a test target, thereby turning off the switches 5a-1 and 5a-2 to switch the other path. To allow the excitation current to be supplied to the coils 3a and 3b.

In this embodiment, a power failure generating circuit 10 is provided in the switchboard 1 in addition to the above-described circuit breaker unit 2 provided for each load. In the power failure generation circuit 10, switches 16a and 13a provided in the middle of wiring for supplying an exciting current to the coils 3a and 3b bypassing the switch 4 are connected in series to the switches 5b-1 and 5b-2, respectively. When the switch 5b of the circuit breaker unit 2 to which the load to be tested is connected is turned on and the load is selected as the test target, the exciting current flows through the coils 3a and 3b of the circuit breaker unit 2 in a path bypassing the switch 4. Supply is possible.

The power failure generating circuit 10 includes auxiliary relays 13,
16 and timed operation instantaneous return relays 12, 14, and 15 are provided in parallel, and a continuous power failure / instantaneous power failure switch 11 is provided in the middle of a path for supplying current thereto. The switch 11 has switches 11a-1 and 11a-2 for an instantaneous power failure test that are turned on and off at the same time, and a switch 11b for a continuous power failure test that is turned on and off separately therefrom.
When the switch 11a-1 or the switch 11b is turned on, current is supplied to the relays 12 and 13 through the switch 11a-1 or the switch 11b.
Operates, the switch 13a is turned on. When the relay 12 operates, the current supply to the relay 13 is cut off, for example, one second after a set time after the operation starts, and the switch 13a is turned off.

When the switch 11a-2 is turned on, a current is supplied to the relay 14 through the switch 11a-2, and the relay 14 turns on the switch 14a after a preset time T. When the switch 14a is turned on, a current flows through the switches 11a-2 and 14a,
6 and the switch 16a is turned on. Relay 1
5 shuts off the current supply to the relay 16 after a set time, for example, 1 second after the current is supplied, and turns off the switch 16a. The above-mentioned time T and one second are for the following description, and these are set to arbitrary values.

A method for performing an instantaneous power failure test and a continuous power failure test using the switchboard 1 having the above configuration will be described. Now, in a state where power is supplied to the load to be subjected to the instantaneous power failure test (the switch 3c is in the closed state), the switch 5b-1 of the test target selection switch 5 of the circuit breaker unit 2 to which the load is connected. , 5b-2 are manually turned on, the switches 5a-1 and 5a-2 are turned off.
c maintains the closed state. Here, the switch 11 for the instantaneous power failure test of the changeover switch 11 is used to perform the instantaneous power failure test.
When a-1 and 11a-2 are manually turned on, as shown in FIG. 2A, the relay 13 is excited at the same time as the turn-on and the switch 13a is turned on, and the exciting current is reduced by the switch 13a.
→ Switch 5b-2 → Flow to trip coil 3b, switch 3c
Is released, and the power supply to the load is cut off. Immediately thereafter (one second after the above example), the switch 12a operated by the relay 12 is released, and the excitation of the relay 13 is cut off, so that the switch 13a is turned off, and the trip coil 3b is turned off.
The supply of the exciting current to the switch is cut off (the open state of the switch 3c is maintained). When the time T elapses after the switches 11a-1 and -2 are turned on, the relay 14 turns on the switch 14a, and current is supplied to the relays 15 and 16 so that the switch 1
6a turns on. As a result, the exciting current is
6a → the switch 5b-1 → the closing coil 3a, and the switch 3c is closed. Immediately thereafter (one second after in the above example), the relay 15 turns off the switch 15a and turns off the relay 1
When the switch 16a is turned off, the supply of the exciting current to the input coil 3a is cut off (the switch 3c is kept closed).

As described above, the power supply to the load is interrupted only during the time T, and it is possible to confirm the interlock or the like due to the instantaneous power failure.

When performing a continuous power failure test of the load, the switch 11b of the changeover switch 11 is manually turned on. As a result, as shown in FIG.
a is closed, the switch 3c is released, and immediately thereafter (after one second in the above example), the supply of the exciting current to the trip coil 3a is interrupted. The open state of the switch 3c is continued even when the switch 11b is turned off, and a continuous power failure state is set. When the power supply to the load is restarted, the selection switches 5b-1 and -2 are turned off (5a-1 and -2 are turned on).
The switch 4a is turned on. This reloading of the load needs to be performed in consideration of the load balance.

Although the power failure generating circuit 10 may be constituted by hardware, it is constituted by software,
The CPU provided in the switchboard 1 can also execute the above-described process of the continuous power failure test and the process of the instantaneous power failure test. Further, these test processing functions of the switchboard can be transferred to a computer provided in the control room and executed to execute the process. A configuration for controlling hardware (such as a circuit breaker) is also possible.

[0021]

According to the present invention, a continuous power failure test and a momentary power failure test of a partial load can be performed without a continuous power failure or a momentary power failure of the whole plant even during the operation of the plant, and a more reliable plant can be constructed. This makes it possible to perform a load test and an interlock test with high reliability in a nuclear power plant.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a switchboard according to an embodiment of the present invention.

FIG. 2 is a time chart of the power failure signal generation circuit shown in FIG.

FIG. 3 is a single-line connection diagram of a typical switchboard.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... switchboard, 2 ... breaker unit, 3 ... breaker, 3a ...
Switch closing coil, 3b ... Switch trip coil, 3c
... Open / close unit, 4 ... On / off switch, 5 ... Test target selection switch, 6 ... Bus, 7 ... Output cable, 10 ... Power failure signal generation circuit, 11 ... Continuous power failure / instantaneous power failure switch, 12,
14, 15 ... timed operation instantaneous return relay, 13, 16 ...
Auxiliary relay.

Claims (3)

[Claims] 1. A switch provided at each load for performing a power failure test and provided on a cable connecting between the load and the power bus, and an exciting coil for electromagnetically turning on / off the switch. A circuit breaker, a breaker provided corresponding to the breaker, an on / off switch for controlling the energization of the exciting coil to open / close the switch, and a breaker provided between the corresponding breaker and the corresponding breaker. A test object selection switch for controlling energization of an exciting coil of the circuit breaker through an energization path bypassing the on / off switch when the gap between the on / off switch and the circuit breaker is released; and the on / off operation by the test object selection switch. A power failure generating means for an instantaneous power failure test for controlling the exciting current flowing through the current path when the current path bypassing the switch is selected, releasing the switch for a set time and interrupting power supply to the load; Prepare A switchboard characterized by that. 2. A switch provided for each load to be subjected to a power failure test, a switch provided in the middle of a cable connecting between the load and the power bus, and an exciting coil for electromagnetically turning on / off the switch. A circuit breaker, a breaker provided corresponding to the breaker, an on / off switch for controlling the energization of the exciting coil to open / close the switch, and a breaker provided between the corresponding breaker and the corresponding breaker. A test object selection switch for controlling energization of an exciting coil of the circuit breaker through an energization path bypassing the on / off switch when the gap between the on / off switch and the circuit breaker is released; and the on / off operation by the test object selection switch. A power failure generating means for a continuous power failure test for controlling the exciting current flowing through the power supply path when the power supply path bypassing the switch is selected to continuously release the switch and cut off the power supply to the load; To prepare Switchboard characterized by the following. 3. A switch provided for each load for performing a power failure test, a switch provided in the middle of a cable connecting between the load and a power bus, and an exciting coil for electromagnetically turning on / off the switch. A circuit breaker, a breaker provided corresponding to the breaker, an on / off switch for controlling the energization of the exciting coil to open / close the switch, and a breaker provided between the corresponding breaker and the corresponding breaker. A test object selection switch for controlling energization of an exciting coil of the circuit breaker through an energization path bypassing the on / off switch when the gap between the on / off switch and the circuit breaker is released; and the on / off operation by the test object selection switch. A power failure generating means for an instantaneous power failure test for controlling an exciting current flowing through the current path when the current path bypassing the switch is selected, releasing the switch for a set time, and interrupting power supply to the load; The test When the energizing path bypassing the on / off switch is selected by the target selection switch, the exciting current flowing through the energizing path is controlled to continuously release the switch and cut off the power supply to the load. A power distribution panel comprising: a test power failure generating means; and a means for selecting any one of the instantaneous power failure test power failure generating means and the continuous power failure test power failure generating means.