JPH0634028B2 - Switchgear test method and device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a test device for verifying the breaking performance of a switchgear, and more particularly to a switchgear tester used in a power factor improving capacitor bank circuit.

[Technical background of the invention]

It is important for the switchgear used in the power factor improving capacitor bank circuit to prevent re-ignition from occurring with respect to the voltage applied between the electrodes of the switchgear after the circuit current is cut off. The reason is that if re-ignition occurs between the electrodes after the circuit current is cut off, a surge voltage is generated, which causes a ground fault, which may lead to an interphase short circuit.

Therefore, in order to prevent re-ignition from occurring in the switchgear used in such a circuit, its breaking performance must be sufficiently verified.

By the way, it is the most preferable to verify the breaking performance of the switchgear in an actual load circuit to determine its suitability, but in recent capacitor bank circuits, the capacity of the capacitor bank is increasing, Along with this, the range in which the three-phase test facility can verify the breaking performance based on the actual load is naturally limited.

Therefore, as a method of verifying the breaking performance equivalent to that in the case of using the three-phase actual load test facility in the past, 1
As introduced in the technical report “Small current switching test method” published by the Institute of Electrical Engineers of Japan in January, a test method that verifies whether or not re-ignition occurs after the circuit current is cut off is adopted. There is.

This test method aims to enable verification of the breaking performance of a large lead power factor current to be equivalent to that in an actual load circuit with a relatively small capacity equipment. A test circuit is composed of a current source circuit for supplying a specified current to the test device) and a voltage source circuit for applying the recovery voltage after the current is cut off. A voltage equivalent to that at the time of cutting off the advance power factor current is applied.

FIG. 4 shows a configuration example of such a conventional synthesis test circuit.

As shown in FIG. 4, both ends of the EUT 4 are connected to the current source power source 1 through the reactor 2 and the auxiliary switchgear 3 in series, and the voltage source power source 5 is connected with the auxiliary switchgear 6 and the capacitor 7 in series. The delay power factor current is supplied from the current source power source 1 to the EUT 4, and the leading power factor current is supplied from the voltage source power source 5 to the EUT 4, and the delay power factor current and the leading power factor current are The recovery voltage after the combined current is cut off by the auxiliary switchgear 3 and the EUT 4 is made equal to that at the time when the power factor current is cut off.

Next, in the test circuit having such a configuration, the operation for verifying the cutoff performance of the DUT 4 will be described with reference to the phenomenon waveform at the time of the test shown in FIG.

In FIG. 4, when a command is given to the auxiliary switchgear 3 and the EUT 4 and both of them are turned ON, the current source power supply 1 delays the EUT 4 via the reactor 2 and the auxiliary switchgear 3. Power factor current 8 flows. When the auxiliary switchgear 6 is turned on, a power factor current 9 flows from the voltage source 5 to the DUT 4 via the auxiliary switchgear 6 and the capacitor 7. Therefore, the combined current 10 of the delayed power factor current 8 and the advanced power factor current 9 flows through the EUT 4. In such a state, if a cutoff command is given to the auxiliary switchgear 3 and the EUT 4 respectively, and they are cut off at the same time, the gap between the EUT 4 advances from the voltage source 5 side and the current is cut off. An inter-electrode voltage equivalent to is applied. In this case, the voltage between contacts is
If the three-phase switchgear is a three-phase switchgear, the voltage condition equivalent to the interrupting first phase is used.
A switchgear with a higher dielectric strength is used.

As described above, the switchgear determines whether re-ignition occurs between electrodes in the actual load circuit by verifying whether the EUT 4 can withstand the voltage between contacts after current interruption. can do.

[Problems of the background art] However, when the switchgear verified by such a test circuit is used in a general power factor improving capacitor bank circuit, the switchgear which has a series reactor connected to the capacitor bank circuit is used. When the capacitor bank circuit is turned on at the maximum voltage phase, the high frequency component may be superimposed on the circuit current when the voltage is turned on, and the maximum peak value may flow about 5 times the circuit current. In addition, as shown in FIG. 6, a capacitor bank circuit in which a series reactor is not connected, or a series reactor having a small impedance is connected, and a power supply is already supplied via a transformer 13 by another switching device 16. When there is a capacitor bank 14 turned on on the 12 side, when the capacitor bank 15 installed in parallel with the capacitor bank 14 in the same system is turned on by the switchgear 17, it is superimposed on the circuit current 18 flowing from the power source 12 side to the switchgear 17. A high-frequency inrush current 19 flows in from the capacitor bank 14 side. Therefore, the peak value of the high-frequency inrush current 19 is very large as compared with the circuit current 18, and the frequency is also high, so there is concern that the switching device 17 may be interrupted.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and its purpose is to verify the breaking performance in consideration of the high-frequency inrush current superimposed on the circuit current when the switchgear is turned on in a relatively small capacity facility. It is intended to provide a test method for a switchgear and a device therefor.

[Summary of the Invention] In order to achieve such an object, the present invention superimposes a high-frequency inrush current on a combined current of a lagging power factor current and a leading power factor current that flows when the EUT is turned on, and applies the current to the EUT after the current interruption. It is characterized by verifying whether or not re-ignition occurs depending on the recovery voltage that is applied.

Example of Invention

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

FIG. 1 shows an example of a circuit configuration for explaining a test method for a switchgear according to the present invention and a device therefor. The same parts as those in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted. The different parts will be described.

In this embodiment, as shown in FIG.
(In the circuit shown in the drawing), a capacitor 20 charged by the power supply 23 through the rectifier 22, a reactor 21, and an auxiliary switchgear 24 are connected in series to both ends of the EUT 4, and an inrush current source circuit is newly added. To do. Then, a command circuit 31 for giving a closing command and a cutting command to the auxiliary opening / closing devices 3, 6, 24 and the DUT 4 is provided.

Next, in the test circuit having such a configuration, the operation in the case where the switchgear used in the capacitor bank circuit is used as the test device 4 to verify its breaking performance will be described with reference to the phenomenon waveforms shown in FIG.

In the test circuit shown in FIG. 1, the parallel capacitor bank 1 shown in FIG.
Charge to a voltage equivalent to the terminal voltage of 5. In such a state, when the auxiliary switchgear 24 is closed by the closing command output from the command circuit 31, the charging voltage of the capacitor 20 is applied between the electrodes of the test device 4 via the reactor 21. In this state, when the EUT 4 is closed by the closing command output from the command circuit 31, the high-frequency inrush current 2 flows from the capacitor 20 via the auxiliary switchgear 24 and the reactor 21.
5 flows to the EUT 4. When the auxiliary switchgear 3 is turned on by the closing command output from the command circuit 31 at the same time as or immediately after the high-frequency inrush current 25 starts to flow to the EUT 4, the current source power source 1 for the current adjusting reactor 2 and the auxiliary switchgear. After 3, the delay power factor current 26 flows to the EUT 4.
Further, when the auxiliary switchgear 6 is turned on by the closing command output from the command circuit 31, a forward power factor current 27 flows from the voltage source power source 5 through the auxiliary switchgear 6 and the capacitor 7 to the DUT 4. Therefore, the cutoff current flowing through the EUT 4 is the combined current 28 of the delayed power factor current 26 and the advanced power factor current 27, and the high frequency inrush current 25 superimposed on this. Here, after the auxiliary switchgear 24 of the inrush current source circuit is cut off by the cutoff command from the command circuit 31, the auxiliary switchgear 3 and the EUT 4 are simultaneously cut off by the cutoff command output from the command circuit 31. A voltage 29 is applied from the voltage source power supply 5 between the electrodes of the container 4. In this case, needless to say, the auxiliary switchgear 3 needs to have a higher dielectric strength than that of the DUT 4.

In this way, as in this embodiment, the high frequency inrush current 25 is superposed on the combined current 28 of the delayed power factor current 26 and the leading power factor current 27 that flows when the EUT 4 is turned on, and the voltage source power source 5 outputs the current after the current interruption. Since the recovery voltage 29 is applied between the electrodes of the EUT 4, if it is verified whether re-ignition occurs with respect to the recovery voltage 29 between the electrodes, the breaking performance considering the high-frequency inrush current is considered. Testing is possible.

Next, another embodiment of the present invention will be described.

In the above embodiment, the capacitor 20 in the inrush current source circuit is used.
The charging circuit is connected to the power source 23 with the rectifier 22 having a unidirectional polarity. However, because of the charging polarity of the capacitor 20 as shown in FIG. 3, the rectifiers 22a, 22b for + and-charging are charged. By providing the polarity switching disconnecting switch 30 for switching between them, the number of poles of the inrush current can be switched. Further, if the polarity switching disconnector 30 can be operated remotely, the efficiency of the test can be improved.

The test circuit shown in FIG. 1 can be implemented in the same manner as described above even if a part of the configuration thereof is as follows.

(A) Normally, since the switchgear has a three-phase integrated structure, if one phase is used as the test device 4 and the other two phases are used as the auxiliary switchgear 3, 6, the opening / closing control can be facilitated. Can be done.

(B) In the test circuit shown in FIG. 1, the power sources of the current source circuit, the voltage source circuit, and the charging circuit were directly connected to each device,
If this is connected to each device via a transformer, a wide range of tests can be performed with a low-voltage power supply.

Further, in the case where the power source 1 is connected to each device via a transformer as in the item (b), it is possible to provide a reactor on either the primary side or the secondary side of the transformer.

(D) In the test circuit shown in FIG. 1, the auxiliary switchgear 3
When the EUT 4 is cut off, the cutoff performance for any arc time can be verified by controlling the cutoff phase.

〔The invention's effect〕

As described above, according to the present invention, the high frequency inrush current is superimposed on the combined current of the delayed power factor current and the leading power factor current flowing when the EUT is turned on, and the recovery voltage is applied between the electrodes of the EUT after the current interruption. By verifying whether or not re-ignition occurs by applying a voltage, it is possible to perform a switching performance test that considers the high-frequency inrush current that is superimposed on the circuit current when the switchgear is turned on in a relatively small capacity facility. An apparatus test method and the apparatus can be provided.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment for explaining a switchgear test method and device therefor according to the present invention, FIG. 2 is a phenomenon waveform diagram during test of a test device in the embodiment, and FIG. FIG. 6 is a diagram illustrating the configuration of a charging circuit according to another embodiment of the present invention,
FIG. 4 is a circuit configuration diagram for explaining a conventional switchgear test method and its device, FIG. 5 is a phenomenon waveform diagram when a test of the EUT is conducted in the test circuit, and FIG. 6 is a switchgear. It is a circuit block diagram for demonstrating the problem when a device is applied to the circuit with a parallel capacitor bank. 1 ... Current source power supply, 2, 21 ... Reactor, 3, 6,
24 ... Auxiliary switchgear, 4 ... EUT, 5 ... Voltage source power supply, 7, 20 ... Capacitor, 22 ... Rectifier, 23 ...
... power supply, 31 ... command circuit.

Claims (5)

[Claims] 1. A delayed power factor current supplied from a current source power source to a test switchgear by supplying a high-frequency inrush current from a charging circuit having a capacitor charged in advance to a predetermined voltage, and simultaneously or immediately thereafter. And a progressive power factor current supplied from a voltage source power supply, and then the charging circuit is cut off, and then the test opening / closing device is cut off at the same time as the current source power supply is cut off. A test method for a switchgear in which an inter-electrode voltage equivalent to that when the current is cut off is applied between the electrodes of the switch. 2. A current source circuit, which is connected to both ends of the test opening / closing device via auxiliary switchgear devices, and which supplies a predetermined delay power factor current to the test opening / closing device, and the test opening / closing device. A power source is connected to both ends of the test opening and closing device via a supplementary switchgear and a voltage source circuit for supplying a predetermined advance power factor current to the test opening and closing device, and an auxiliary switchgear at both ends of the test opening and closing device. An inrush current source circuit connected to a capacitor charged by a charging power source and supplying a high-frequency inrush current to the DUT, and an auxiliary switching device for the inrush current source circuit when the DUT is turned on. At the same time as or immediately after the closing command is given, the closing command is given to the auxiliary switchgear of the current source circuit and the voltage source circuit, respectively, and before the test switchgear is cut off, the auxiliary switchgear of the inrush current source circuit is provided. Sha Test apparatus of the switchgear, characterized in that a command circuit for providing a command. 3. A switchgear test apparatus according to claim 2, wherein the current source circuit is one in which a power source, a reactor and an auxiliary switchgear are connected in series to the test switchgear. 4. The switchgear test apparatus according to claim 2, wherein the voltage source circuit is a test switchgear in which a power source, a capacitor and an auxiliary switchgear are connected in series. 5. The capacitor of the inrush current source circuit connected to both ends of the test opening / closing device via the auxiliary opening / closing device is connected to the charging power source so that the charging polarity can be switched. The switchgear testing device according to.