WO2018042516A1

WO2018042516A1 - Mechanical switch testing method and testing device therefor

Info

Publication number: WO2018042516A1
Application number: PCT/JP2016/075328
Authority: WO
Inventors: 優平橋本; 健作宮崎; 小山　博; 和長金谷; 網田　芳明
Original assignee: 株式会社東芝
Priority date: 2016-08-30
Filing date: 2016-08-30
Publication date: 2018-03-08

Abstract

Provided are a mechanical switch testing method and a testing device therefor for verifying the interruption capability of a mechanical switch used in a direct current circuit breaker. The testing method uses the testing device, which is equipped with a current source circuit A and a voltage source circuit B, to verify the interruption capability of the mechanical switch 1 used in the direct current circuit breaker, the method comprising supplying a current from the current source circuit A to the mechanical switch 1, opening the mechanical switch 1, stopping the current supply from the current source circuit A to the mechanical switch 1, and, after a predetermined time has elapsed, applying a return voltage from the voltage source circuit B to the mechanical switch 1.

Description

Test method and test apparatus for mechanical switch

Embodiments of the present invention relate to a test method and a test apparatus for verifying the breaking performance of a mechanical switch used for a DC circuit breaker.

In DC systems such as DC transmission systems, DC circuit breakers are used to interrupt system faults. As a direct current circuit breaker responsible for system protection from a short circuit accident of a direct current system, for example, a hybrid direct current circuit breaker including a mechanical switch and a semiconductor circuit breaker connected in parallel to the switch is used. As shown in FIG. 3, this type of DC circuit breaker 119 includes a semiconductor circuit breaker 122 and a protective lightning arrester 123 connected in parallel to a normal energization unit composed of a mechanical switch 120 and a load commutation device 121. Composed.

Japanese Patent Laid-Open No. 2015-056389 International Publication No. 2014/064000

In the DC circuit breaker 119 described above, normally, a DC current is passed through the mechanical switch 120 and the load commutation device 121 to detect the occurrence of a short circuit accident, and then the load commutation device 121 passes the current path through the semiconductor circuit breaker. 122. After the fault current completely flows to the semiconductor circuit breaker 122, the fault current is interrupted by the semiconductor circuit breaker 122, and the DC system that suppresses the generated recovery voltage by the protective lightning arrester 123 is protected.

Here, the process from the occurrence of a short circuit accident to the interruption of the accident current will be described with reference to FIG. When a short circuit accident occurs in the DC system at time (a), the energization current i1 of the mechanical switch 120 starts to increase. When occurrence of a short circuit accident is detected at time (b) and a short circuit accident current interruption command is sent to the DC circuit breaker 119, the mechanical switch 120 starts to open, and the time between the terminals of the mechanical switch 120 is Until (d), an arc is generated and current continues to flow.

From time (c) to time (d), the fault current is transferred to the semiconductor circuit breaker 122 by the load commutation device 121, and the current i2 increases in the circuit breaker 122. Then, at time (d), the transition of the energization path is completed, the mechanical switch 120 is not energized, and the fault current continues to flow through the semiconductor circuit breaker 122 until time (g).

At time (e), the semiconductor breaker 122 starts to cut off the accident current, and the capacitor of the snubber circuit in the semiconductor breaker 122 is charged, whereby the voltage V between the terminals of the DC breaker 119 starts to rise. Thereafter, at time (f), the inter-terminal voltage V reaches the operation start voltage of the protective lightning arrester 123 connected in parallel to the semiconductor breaker 122, and the current i3 starts to flow through the lightning arrester 123.

And after interruption | blocking by the semiconductor circuit breaker 122 is completed at the time (g), as for the electric current which flows into the protective lightning arrester 123, the voltage V between terminals reaches a recovery voltage peak value at the time (h), and time (i ) Continue to flow until the voltage suppression is finished.

As described above, the DC circuit breaker protects the system from accidents in cooperation with mechanical switches and semiconductor circuit breakers.

By the way, it is necessary to confirm that the DC circuit breaker as described above has the interruption performance necessary for accident interruption of the DC system. In the case of the hybrid type DC circuit breaker as described above, conventionally, a test method for evaluating the breaking performance of the entire DC circuit breaker is known.

However, there is no known test method for evaluating the responsibilities required for a mechanical switch used in a DC circuit breaker alone, and the circuit breaker performance must be tested for the entire DC circuit breaker. . For this reason, there is a problem that it is difficult to find out which configuration causes the failure due to the DC circuit breaker.

A DC circuit breaker test method according to an embodiment of the present invention is made to solve the above-described problems, and is a mechanical switch that verifies the breaking performance of a mechanical switch used in a DC circuit breaker. It is an object of the present invention to provide a test method for a vessel and a test apparatus therefor.

In order to achieve the above object, the mechanical switch testing method of the present embodiment is used for a DC circuit breaker for verifying the breaking performance by using a test apparatus including a current source circuit and a voltage source circuit. A test method for a mechanical switch, wherein current is supplied from the current source circuit to the mechanical switch, the mechanical switch is opened, and current is supplied from the current source circuit to the mechanical switch. And a recovery voltage is applied from the voltage source circuit to the mechanical switch after a predetermined time has elapsed.

Further, the mechanical switch test device of the present embodiment is a mechanical switch test device used for a DC circuit breaker, and a current source circuit for supplying a current to the mechanical switch, A voltage source circuit that applies a recovery voltage to the mechanical switch, the current source circuit supplying a current to the mechanical switch, the current supply unit, and the mechanical switch And a switch provided in parallel with the current supply unit. The resistor is provided in series between the current supply unit and the current supply unit.

It is a circuit diagram which shows the structure of the testing apparatus of the mechanical switch used for the DC circuit breaker concerning this embodiment. It is a figure which shows the electric current and voltage waveform in the test method of this embodiment. It is a figure which shows the structure of a DC circuit breaker. It is a figure which shows the electric current and voltage waveform in the test method of a DC circuit breaker.

[1-1. Constitution]
Below, the test method of the mechanical switch which concerns on this embodiment, and the test apparatus used for the test method are demonstrated, referring FIG.1 and FIG.2. FIG. 1 is a circuit diagram illustrating a configuration of a test device for a mechanical switch according to the present embodiment.

The test device of the mechanical switch 1 is a device that tests the breaking performance of the mechanical switch 1 to be tested. The mechanical switch 1 is a device that has a physical contact made of a conductor or the like, and switches between a conductive state and a cut-off state by the contact of the contact. This mechanical switch 1 is a switch used for a DC circuit breaker, and is a switch that constitutes a DC circuit breaker that is connected in parallel with a semiconductor circuit breaker and blocks a direct current. Examples of the direct current system in which the direct current circuit breaker is used include direct current power transmission systems such as long-distance power transmission and between electric power companies, direct current distribution such as buildings and large commercial facilities, and direct current systems such as electric railways.

As shown in FIG. 1, the test device for the mechanical switch 1 includes a current source circuit A, a voltage source circuit B, and a control unit (not shown) for controlling these circuits A and B. The said control part is connected with the current source circuit A and the voltage source circuit B, and controls the connection or interruption | blocking timing of the component of each circuit A and B. FIG. The current source circuit A and the voltage source circuit B are connected in parallel to the mechanical switch 1 to be tested.

The current source circuit A is a circuit for supplying an accident current and supplies current to the mechanical switch 1. The current source circuit A includes a short-circuit generator 2, a protective circuit breaker 3, a closing switch 4, a reactor 5, an auxiliary circuit breaker 6, a resistor 7, a surge absorber 8, and an opening / closing switch 10.

The short-circuit generator 2 is a generator that generates a short-circuit current, and is a current supply unit that supplies current equivalent to an accident current to the mechanical switch 1. The short circuit current generated from the short circuit generator 2 is an alternating current. The short-circuit current generated in the short-circuit generator 2 is output to the mechanical switch 1 via the reactor 5 connected in series to the short-circuit generator 2.

A protective circuit breaker 3 and a closing switch 4 are provided between the short-circuit generator 2 and the mechanical switch 1. The input switch 4 is a switch for connecting the short-circuit generator 2 to the test circuit, and switches between connection and disconnection of the short-circuit generator 2 to the mechanical switch 1 to be tested. The protective circuit breaker 3 is a circuit breaker that blocks AC short-circuit current flowing in the current source circuit A. The protective circuit breaker 3 cuts off at the current zero point of this AC short-circuit current.

The auxiliary circuit breaker 6 is connected in series with the short-circuit generator 2 and switches between connection and disconnection between the mechanical switch 1 and the short-circuit generator 2 to be tested. The auxiliary circuit breaker 6 is a mechanical circuit breaker having a contact made of, for example, a conductor. When the auxiliary circuit breaker 6 is in the on state, current can be supplied from the short-circuit generator 2 to the mechanical switch 1, and when the auxiliary circuit breaker 6 is in the break state, the current source circuit A is mechanically opened and closed. It can be separated from the vessel 1.

The resistor 7 is provided in series between the short-circuit generator 2 and the mechanical switch 1. Here, the resistor 7 is provided between the auxiliary circuit breaker 6 and the mechanical switch 1. The surge absorber 8 is provided in parallel with the mechanical switch 1 and is connected to the auxiliary circuit breaker 6. The surge absorber 8 absorbs a surge that occurs when the auxiliary circuit breaker 6 is interrupted. The surge absorber 8 includes a resistor 8a and a capacitor 8b connected in series. The capacitor 8b absorbs the surge through the resistor 8a and facilitates the interruption by the auxiliary circuit breaker 6.

The open / close switch 10 is a switch that branches between the short-circuit generator 2 and the resistor 7 and is provided in parallel with the short-circuit generator 2 and the mechanical switch 1. The energization path of the current source circuit A is switched by opening / closing the open / close switch 10. That is, if the open / close switch 10 is in the open state, the current source circuit A is one closed circuit to which the configurations 1 to 7 can be connected. If the open / close switch 10 is in the closed state, the configurations 1 to 5 and 10 are One closed circuit that can be connected.

The voltage source circuit B is a circuit for applying a recovery voltage, and applies a recovery voltage to the mechanical switch 1. More specifically, the voltage source circuit B applies a DC voltage corresponding to the DC circuit breaker rated peak value between the terminals of the mechanical switch 1 that has been opened. The voltage source circuit B includes a voltage source capacitor 12, a charging device 11, a start switch 13, a reactor 14, a resistor 15, and a capacitor 16.

The voltage source capacitor 12 is a DC capacitor serving as a voltage source for the voltage source circuit B. The voltage source capacitor 10 applies a recovery voltage to the mechanical switch 1 via the reactor 14 when the start switch 13 is in the on state. The voltage source capacitor 10 has a capacity for supplying a part of a short-circuit current at the time of a system fault in a DC system provided with a DC circuit breaker provided with the mechanical switch 1. The recovery voltage may be used in combination with another capacitor for adjusting the transient recovery voltage.

The charging device 11 is a device that is connected in parallel with the voltage source capacitor 12 and charges the voltage source capacitor 12. The start switch 13 is a device that switches on and off the voltage application from the voltage source capacitor 12.

The voltage source circuit B includes a transient oscillation circuit (LCR circuit) using the voltage source capacitor 12 as a DC voltage source. That is, the reactor 14, the resistor 15, and the capacitor 16 are connected in series to the voltage source capacitor 12, and constitute a transient vibration circuit. This transient vibration circuit adjusts the voltage applied to the mechanical switch 1 by generating a transient phenomenon. For this reason, the recovery voltage applied to the mechanical switch 1 by the voltage source circuit B is a high-frequency voltage.

The capacitor 16 is a voltage adjusting capacitor that adjusts the voltage supplied by the voltage source capacitor 12. Here, the capacitor 16 is a capacitor that is used in combination with the voltage source capacitor 12 to adjust the voltage applied to the mechanical switch 1 when a DC system fault occurs.

[1-2. Test method]
A test method for the mechanical switch 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 2 is a waveform diagram of an accident current flowing through the mechanical switch 1 to be tested and a voltage applied between the terminals of the mechanical switch 1.

First, at the start of the test, the mechanical switch 1, the protective circuit breaker 3, and the auxiliary circuit breaker 6 are closed, and the closing switch 4, the open / close switch 10, and the start switch 13 are open. The short-circuit generator 2 is in an excited state at a predetermined voltage in advance, and the voltage source capacitor 12 is in a state charged to a predetermined voltage by the charging device 11.

As shown in FIG. 2, when the closing switch 4 is closed at time (a), the magnitude of the AC current supplied from the short-circuit generator 2 is adjusted by the reactor 5 and the resistor 7, and the mechanical switch 1. Is supplied with an alternating current.

Next, at time (b), the mechanical switch 1 and the auxiliary circuit breaker 6 are opened. This opening is performed, for example, until the alternating current supplied by the short-circuit generator 2 reaches its peak. Since both the mechanical switch 1 and the auxiliary circuit breaker 6 are devices having mechanical contacts, an arc is generated between the terminals of the mechanical switch 1 and the auxiliary circuit breaker 6 even when the circuit is opened. The current continues to flow between the terminals until time (d).

At time (d), the accidental current from the short-circuit generator 2 is transferred from the auxiliary circuit breaker 6 and the mechanical switch 1 to the open / close switch 10 by closing the open / close switch 10, and the auxiliary switch 10. No current flows through the circuit breaker 6 and the mechanical switch 1. This is because a resistor 7 is provided between the auxiliary circuit breaker 6 and the mechanical switch 1, and a current flows to the switch 10 having a lower resistance. At this time (d), the current supply from the current source circuit A to the mechanical switch 1 is stopped.

By closing the start switch 13 of the voltage source circuit B at a time (e) after a lapse of a predetermined time from the time (d) at which no current flows to the mechanical switch 1, the voltage source capacitor 12, the reactor 14, the resistance 15 and a voltage having a frequency determined by the capacitor 16 are applied to the mechanical switch 1. Here, the time from time (d) to time (e) is the time when a system failure occurs in a DC circuit breaker equipped with a mechanical switch 1 and a semiconductor circuit breaker provided in parallel with the mechanical switch 1 used in the DC system. This is the time corresponding to the time when current flows only through the circuit breaker. In other words, it is a time during which no current flows and no voltage is applied to the mechanical switch 1.

Then, after the voltage is applied to the mechanical switch 1 as described above, the voltage peak value is reached at time (h). Thereafter, after the voltage is lowered, the voltage source circuit B is stopped and the test is terminated.

In the above implementation process, the arc energy applied between the terminals of the mechanical switch 1 from time (b) to time (d) and the voltage between the terminals of the mechanical switch 1 applied after time (e) are DC. The performance of the mechanical switch 1 can be evaluated by making it equal to or greater than the arc energy applied between the terminals of the mechanical switch and the voltage applied between the terminals in the event of a system failure.

The arc energy here is multiplied by the voltage V applied between the terminals of the mechanical switch 1, the current I flowing through the mechanical switch 1, and the time t during which the voltage V and the current I are supplied. It is electric energy (P = V * I * t).

In FIG. 2, the current corresponding to the accident current is supplied by the short-circuit generator 2 so as to rise toward the peak of the AC current. However, since the arc energy required for the mechanical switch 1 can be supplied, the AC current You may supply the electric current equivalent to an accident electric current so that it may fall from a peak. For example, the mechanical switch 1 and the auxiliary circuit breaker 6 are opened at the timing when the AC current falls from the peak (time (b)), and the open / close switch 10 is closed at the timing when the AC current reaches the current zero point (time (d)). Anyway. In this case, the resistor 7 and the open / close switch 10 need not be provided in the current source circuit A. Even if arc conduction occurs in the mechanical switch 1 and the auxiliary circuit breaker 6 between time (b) and time (d), the arc also disappears at the current zero point of the alternating current, so the current and voltage are mechanically switched. This is because it is not supplied to the container 1 and there is no need to shift the energization path.

Further, the recovery voltage waveform applied between the terminals of the mechanical switch 1 is not limited to the waveform of FIG. That is, the time from the time (e) when the start switch 13 is closed to the time (h) when the voltage peak value is reached, and the voltage peak value are applied between the terminals of the mechanical switch at the time of the DC system fault. It is sufficient if the voltage can be simulated. For example, a waveform that rises linearly to the voltage peak value from time (e) to time (h) and then falls may be used.

[1-3. effect]
(1) The test method for the mechanical switch 1 according to the present embodiment is a mechanical switch used for a DC circuit breaker for verifying the breaking performance using a test apparatus including a current source circuit A and a voltage source circuit B. This is a test method for the device 1, supplying current from the current source circuit A to the mechanical switch 1, opening the mechanical switch 1, and stopping supply of current from the current source circuit A to the mechanical switch 1. The recovery voltage is applied from the voltage source circuit B to the mechanical switch 1 after a predetermined time has elapsed.

Thereby, it is possible to evaluate the breaking performance of the mechanical switch 1 used in the DC breaker. That is, when the mechanical switch 1 constitutes a DC circuit breaker together with a semiconductor circuit breaker connected in parallel with the switch 1, when the DC circuit breaker is actually used, Since a current flows through the semiconductor circuit breaker and the current is interrupted by the semiconductor circuit breaker, there is a time during which no current flows through the mechanical switch 1 and no voltage is applied. In this respect, according to the test method of the present embodiment, the time when the current and voltage are not supplied to the switch 1 after the mechanical switch 1 is cut off can be reproduced. The interruption | blocking performance of the mechanical switch 1 itself incorporated can be detected.

As a result, conventionally, it was only possible to evaluate the breaking performance of the entire DC breaker, and when breaking by the breaker failed, it took time to investigate which component device caused the failure. However, according to the test method of the present embodiment, it is possible to test the breaking performance of the mechanical switch 1 alone, which is a component device thereof, so that it is possible to shorten the time required for investigating the cause. In addition, since the insulation performance between the electrodes of the mechanical switch 1 after the arc energization is restored over time, the burden on the improvement of the insulation performance between the electrodes of the mechanical switch 1 should be reduced. There is also an advantage that can be.

The fault current supplied to the mechanical switch 1 is such that the arc energy applied between the terminals of the mechanical switch 1 is equivalent to or greater than the arc energy applied between the terminals of the mechanical switch 1 in a DC system fault. Therefore, it is not necessary for the current source circuit A to supply a direct current that flows to the direct current system in a steady state. Since the voltage source circuit B only needs to apply a voltage corresponding to the recovery voltage after interruption of the fault current, it is sufficient to provide a transient vibration circuit with a simple configuration including a capacitor, a reactor, and a resistor in the test apparatus. Therefore, if a general AC circuit breaker high power test facility such as a short circuit generator is provided, a test apparatus for evaluating the performance of the mechanical switch 1 alone can be obtained without using a semiconductor circuit breaker. There is no need to prepare a site for capital investment or equipment placement, and there is an economic advantage.

(2) The current source circuit A supplies an alternating current descending from the peak to the mechanical switch 1, opens the mechanical switch 1 until the alternating current reaches the current zero point from the peak, and the alternating current is the current zero point. At this point, the current supply to the mechanical switch 1 is stopped.

This makes it possible to relatively easily supply and stop an alternating current, so that the breaking performance of the mechanical switch 1 can be easily tested.

(3) The current source circuit A supplies an alternating current to the mechanical switch 1, opens the mechanical switch 1 until the alternating current reaches its peak, and then switches from the current source circuit A to the mechanical switch 1. The current supply was stopped. As a result, the breaking performance of the mechanical switch can be tested in a manner that simulates the actual occurrence of an accident in which the current increases, so that the breaking performance can be more accurately evaluated.

(4) The test device for the mechanical switch 1 according to the present embodiment is a test device for the mechanical switch 1 used in a DC circuit breaker, and a current source circuit that supplies current to the mechanical switch 1 A and a voltage source circuit B that applies a recovery voltage to the mechanical switch 1, and the current source circuit A includes a short-circuit generator 2 that supplies current to the mechanical switch 1, and a short-circuit generator A resistor 7 provided in series between the mechanical switch 1 and the mechanical switch 1, and a switch 10 provided in parallel with the short-circuit generator 2, branching between the short-circuit generator 2 and the resistor 7, I was prepared to.

As a result, the machine is generated when the semiconductor circuit breaker used for the DC circuit breaker is interrupted between the time after the current is supplied to the mechanical switch 1 by the current source circuit A and the time when the recovery voltage is applied by the voltage source circuit B. Since it is possible to provide a time simulating that current and voltage are not supplied to the type switch, the breaking performance of the mechanical switch 1 alone used in the DC circuit breaker can be tested.

[2. Other Embodiments]
In the present specification, a plurality of embodiments according to the present invention have been described. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof, as long as they are included in the scope and gist of the invention.

As other embodiments, the above-described test method may be realized by providing a control unit, or the switches of the circuits A and B may be turned on or off by an operator. When the control unit is provided, the control unit is a computer having a recording medium in which a program for sequence management is stored, and by executing the program, each device of each of the circuits A and B has a predetermined timing. To output a connection or disconnection command.

Instead of the short-circuit generator 2 of the above embodiment, a current supply unit that supplies current to the mechanical switch 1 using an LC resonance circuit may be configured.

DESCRIPTION OF SYMBOLS 1 Mechanical switch A Current source circuit 2 Short circuit generator 3 Protective circuit breaker 4 Input switch 5 Reactor 6 Auxiliary circuit breaker 7 Resistance 8 Surge absorption part 8a Resistance 8b Capacitor B Voltage source circuit 11 Charging device 12 Voltage source capacitor 13 Start switch 14 Reactor 15 Resistor 16 Capacitor

Claims

A test method for a mechanical switch used in a DC circuit breaker for verifying a breaking performance using a test device including a current source circuit and a voltage source circuit,
Supplying current from the current source circuit to the mechanical switch;
Open the mechanical switch,
Stopping the current supply from the current source circuit to the mechanical switch;
Applying a recovery voltage from the voltage source circuit to the mechanical switch after elapse of a predetermined time;
Test method for mechanical switches characterized by
The current source circuit supplies an alternating current descending from a peak to the mechanical switch,
Open the mechanical switch until the alternating current reaches the current zero point from the peak,
Stopping the current supply to the mechanical switch when the alternating current reaches the current zero point;
The method for testing a mechanical switch according to claim 1.
The current source circuit supplies an alternating current to the mechanical switch,
Opening the mechanical switch until the peak of the alternating current and stopping the current supply from the current source circuit to the mechanical switch;
The method for testing a mechanical switch according to claim 1.
A test device for a mechanical switch used in a DC circuit breaker,
A current source circuit for supplying current to the mechanical switch;
A voltage source circuit for applying a recovery voltage to the mechanical switch;
With
The current source circuit is:
A current supply for supplying current to the mechanical switch;
A resistor provided in series between the current supply unit and the mechanical switch;
A switch branched between the current supply unit and the resistor, and provided in parallel with the current supply unit;
An apparatus for testing a mechanical switch, comprising: