JP2010008304A - Method and device for ac withstand voltage test - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To apply a large voltage cross terminals without increasing a voltage to ground. <P>SOLUTION: A switch 7 including a pair of terminals and a capacitor 8 connected in parallel with the terminal are provided inside a switch device 6. A test AC voltage generator 1 and a test AC voltage generator 2 are connected to two external terminals of the switch device 6, respectively. A voltage is supplied to the primary side of the test AC voltage generator 1 connected to the one terminal via a voltage regulator 3 from a power generator 5, and a compensation reactor 4 is further connected thereto. The power generator 5 is directly connected to the primary side of the test AC voltage generator 2 connected to the terminal at the opposite side. The power generator 5 is connected so that a phase of the test AC voltage generator 2 at the terminal at the opposite side is shifted by 180 degrees from a phase of the output voltage of the test AC voltage generator 1 at the one terminal. The output voltage of the power generator 5 is commonly supplied as the primary side voltage of the test AC voltage generator 1 and the test AC voltage generator 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to an AC withstand voltage test method and apparatus between internal terminals of a gas-insulated switchgear, and in particular, conducts a withstand voltage test by applying a higher voltage than that at the time of an AC withstand voltage test between ground. It relates to a test method and apparatus that can be used.

The basic configuration of a gas-insulated switchgear includes a metal container that contains an insulating gas and is grounded, and a switch for opening and closing the current-carrying conductor, into which a current-carrying conductor to which a high voltage is applied is inserted. Have Some types of gas-insulated switchgear have capacitors arranged in parallel between the terminals of the switch.

In the conventional withstand voltage test between terminals according to the conventional standard for the gas-insulated switchgear having the above-described configuration, the test voltage value that must be verified between the terminals and the test voltage value that must be verified between the terminals are the same. Therefore, it was possible to carry out an AC withstand voltage test of the switchgear with one AC voltage generator for testing. Patent Documents 1 to 4 are known techniques showing such conventional AC withstanding voltage test methods and apparatuses.

As shown in FIG. 3, in these known art ground-to-ground AC withstand voltage tests, the switchgear 6 is connected to a single test AC voltage generator 1 with the switch 7 of the switchgear 6 closed. Voltage source 5
Through the voltage regulator 3 and connected to the primary side of the test AC voltage generator, and the compensation reactor 4
Is adjusted to minimize the primary current value, and an AC voltage is applied to the switchgear 6 to perform an AC withstanding voltage test between the ground.

The AC voltage-to-voltage test between terminals is performed as shown in FIG.
One is connected with the switch 7 of the switchgear 6 open, and the other terminal is grounded. The voltage source 5 is passed through the voltage regulator 3 and connected to the primary side of the test AC voltage generator, and the compensation reactor 4 is adjusted to minimize the primary side current value. The AC withstand voltage test between terminals is carried out by applying.

JP-A-6-213978 JP-A-6-269109 JP 2000-35457 A JP-A-2005-241297

By the way, in the conventional test method for the above-described test apparatus, when the inter-terminal test voltage value is larger than the test voltage value between the ground, a voltage of the same magnitude is applied between the ground,
There was a problem that the possibility of dielectric breakdown occurring between the ground and the ground increases. However, recently, a voltage higher than the test voltage between the ground may be required as the test voltage between terminals, and such a case cannot be handled by the conventional technology.

As a solution to this problem, the present inventors have connected a conventional test apparatus to one terminal and another test apparatus having the same configuration to the other terminal, and the voltages applied to both terminals are reversed. A test device was proposed that was in phase. Certainly, in such a device, although a high voltage could be applied between the terminals, it was found that there were the following problems depending on the type of switchgear.

That is, some large-capacity switchgear devices have capacitors connected in parallel with the terminals in order to equalize the voltage applied between the terminals and obtain a high cutoff performance. In such a device, when the circuit of FIG. 4 is connected to each terminal, current flows through the capacitor 8. As a result, the load viewed from one test circuit becomes a circuit including the circuit breaker and the other test circuit, and it is impossible to apply a voltage having an opposite phase between both terminals.

Moreover, in the test circuit, when the resonant capacitance of the compensating reactor 4 with respect to the ground of the test switchgear (load capacity of the test switchgear) is LC-resonated, the current of the power supply is reduced. Can do. That is, in general, the current phase of the reactor and the capacitor is shifted by 180 °, so that the current is reduced by resonating both.

Therefore, when a conventional test circuit is connected to both terminals, the L
It is necessary to adjust the balance between the two circuits by setting the circuit constants of the two circuits connected to both terminals so that C resonance occurs. However, there is a case where the voltage adjustment of one circuit is required at the time of the test. In such a case, the circuit constant of one circuit is changed, the balance with the circuit on the opposite side is lost, and the LC resonance is impaired. It is.

In order to eliminate the influence of the change in the circuit constant of one of the circuits, it is conceivable that the circuit is formed out of the resonance point. In this case, since LC resonance does not occur, a large amount of current flows. However, it is not preferable to flow a large current in the high voltage test apparatus. Therefore, simply connecting a conventional circuit to both terminals does not solve the problem.

The present invention has been proposed to solve the above-described problems of the prior art, and a first object of the present invention is to provide grounding between terminals without applying an overvoltage between grounding switchgears. An object of the present invention is to provide an AC withstanding voltage test method and apparatus for applying an AC voltage equal to or higher than a test voltage to perform a test.

The second object of the present invention is to secure LC resonance and reduce the current of the power source when applying an anti-phase alternating current between both terminals connected in parallel with a capacitor.
An object of the present invention is to provide an AC withstanding voltage test method and apparatus capable of easily controlling a voltage applied to one terminal without destroying resonance.

In order to achieve the above object, the present invention uses two test AC voltage generators, shares the power supply voltage on the primary side of the AC voltage generator, and changes the connection so that they are in opposite phases. The withstand voltage test is performed by applying an AC voltage having an opposite phase between terminals of the gas-insulated switchgear.

Of the two test circuits, one is controlled by the voltage regulator regardless of the common primary power supply voltage.
The test circuit can control the secondary output voltage, and the other can be a test circuit that directly controls the secondary output voltage using a common primary power supply voltage.

As a primary voltage source common to the two AC voltage generators, a large-capacity generator capable of flowing a large current and having a variable output voltage can be used.

Of the two test circuits consisting of two test AC voltage generators, the test circuit consisting of one test AC voltage generator is compensated with a compensation reactor so that the primary power supply current is minimized. The withstand voltage test circuit that directly controls the secondary output voltage with the voltage of the other generator output may be a test circuit configuration that does not use a compensation reactor.

Of the test circuits composed of the two test AC voltage generators, a voltage source is provided on the primary side of the AC voltage generator of the test circuit that controls the output voltage value using one inductive voltage regulator. To connect the voltage source only to the test circuit side that controls the secondary output voltage of the AC voltage generator with the other generator output, and to generate a reverse-phase voltage between the terminals. You can also.

According to the present invention, it is possible to apply a large voltage between the terminals without increasing the ground voltage by applying an anti-phase AC voltage between the terminals. In particular, in the case where a capacitor is connected in parallel with the terminals and the test AC voltage generator connected to one of the terminals has a test circuit configuration that does not use a compensation reactor, the state in which the occurrence of LC resonance is secured Thus, the voltage applied to the terminal on one side can be controlled, and an arbitrary differential voltage can be applied between the terminals.

In addition, when a capacitor is connected in parallel with the terminals, a voltage source is not connected to one terminal, but a current is passed from the voltage source to the circuit on the opposite side via the capacitor, so that the opposite side It is possible to generate an antiphase voltage in the circuit. In that case, since the voltage source only needs to be on one terminal side, the apparatus can be simplified.

Embodiments of an AC withstanding voltage test method and apparatus according to the present invention will be described below with reference to the drawings. 3 and 4 are denoted by the same reference numerals, and description thereof is omitted.

(1. First embodiment)
(1-1. Configuration)
A first embodiment of the present invention will be described with reference to FIG. In FIG. 1, the switchgear 6 includes a switch 7 inside, and a capacitor 8 is connected in parallel between the internal terminals of the switch 7. The test AC voltage generator 1 and the test AC voltage generator 2 are connected to two external terminals of the switchgear 6 respectively. A voltage is supplied from the generator 5 via the voltage regulator 3 to the primary side of the test AC voltage generator 1 connected to one external terminal, and a compensation reactor 4 is further connected.

The generator 5 is directly connected to the primary side of the test AC voltage generator 2 connected to the opposite external terminal. Further, the generator 5 has the phase of the output voltage of the test AC voltage generator 1 at one external terminal and the phase of the output voltage of the test AC voltage generator 2 at the opposite external terminal 1.
They are connected so as to be offset by 80 degrees.

(1-2. Action)
According to the first embodiment having such a configuration, the output voltage of the generator 5 is commonly supplied as the primary voltage of the test AC voltage generator 1 and the test AC voltage generator 2 and is used for the test. It acts to generate an AC high voltage on the secondary side of the AC voltage generator 1 and the test AC voltage generator 2.

Since the output voltage of the generator 5 is connected to the primary side of the test AC voltage generator 1 through the voltage regulator 3, the test AC voltage generator is changed even if the output voltage of the generator 5 changes. 1 of 1
An arbitrary voltage can be applied to the secondary side. Further, a compensation reactor 4 is connected to the primary side of the test AC voltage generator 1, and acts to reduce the primary current by generating LC resonance by adjusting the reactor capacity.

Since the generator 5 is directly connected to the primary side of the test AC voltage generator 2, the generator 5
It is possible to control the secondary output voltage of the test AC voltage generator 2 with the output voltage. Since the test AC voltage generator 2 has a circuit configuration in which the compensation reactor 4 is not connected, the primary current is increased, but the circuit has a low impedance configuration, so that the generator output fluctuations and the test AC voltage generator are 1 is very difficult to be influenced by the other test circuit including 1 and hardly affects the other circuit, so that the voltage control of the test AC voltage generator 1 and the test AC voltage generator 2 can be easily performed. Can do.

(1-3. Effect)
As described above, in the first embodiment, since the primary power supply of the test AC voltage generator 1 and the test AC voltage generator 2 is common, the voltage phase on the output side is changed to about 180 degrees by changing the connection. It becomes possible to shift. Accordingly, it is possible to apply an AC voltage having an opposite phase between the external terminals of the switchgear 6.

Since the voltage regulator is installed in the test AC voltage generator 1, the output voltage value of the test AC voltage generator 1 and the output voltage value of the test AC voltage generator 2 can be controlled separately. It becomes. Since the voltage applied between the terminals of the switchgear 6 can be evaluated as a difference voltage between the AC voltages having opposite phases, it is possible to carry out a withstand voltage test of an AC voltage having a terminal voltage larger than the ground voltage.

(2. Second Embodiment)
(2-1. Configuration)
Next, a second embodiment of the AC withstanding voltage test apparatus according to the present invention will be described with reference to FIG. In FIG. 2, the generator 5 is connected only to the test AC voltage generator 2 and has a circuit configuration in which no voltage source is connected to the voltage regulator 3 connected to the primary side of the test AC voltage generator 1. .

(2-2. Action)
According to the second embodiment, the circuit of the test AC voltage generator 1 has a circuit configuration in a resonance state such that the primary side current becomes the minimum value. When a current is passed through the secondary circuit of the test AC voltage generator 1 through the capacitor 8, a reversely excited current flows through the primary side of the test AC voltage generator 1. The current generated on the primary side flows to the inductive voltage regulator 3, and a voltage having an opposite phase is generated in the voltage regulator 3. When the voltage is generated in the voltage regulator 3, an antiphase voltage is generated on the secondary side of the test voltage regulator 1, and an antiphase AC high voltage is applied between the terminals of the switchgear 6.

(2-3. Effect)
As described above, according to the second embodiment, the withstand voltage test in which an AC voltage having an opposite phase is applied between the terminals of the switchgear 6 is applied to the generator 5 in one of the two test AC voltage generators. By taking a connected circuit configuration, an AC withstand voltage test can be easily performed. Because the circuit configuration is simple, it is possible to install a second test AC voltage generator even if only one test AC voltage generator is usually owned, without requiring large-scale power supply construction. become. In addition, since the voltage can be controlled by the induced voltage regulator 3 without connecting a voltage source, an arbitrary difference voltage can be applied between the terminals.

The figure which shows the circuit structure of the alternating current withstand voltage test method of 1st Embodiment of this invention. The figure which shows the circuit structure of the alternating current withstand voltage test method of 2nd Embodiment of this invention. The figure which shows the conventional earth-to-ground alternating voltage withstand voltage test circuit structure. The figure which shows the conventional inter-terminal alternating voltage withstand voltage test circuit structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Test AC voltage generator 2 ... Test AC voltage generator 3 ... Voltage regulator 4 ... Compensation reactor 5 ... Generator 6 ... Switching device 7 ... Switch 8 ... Capacitor

Claims (7)

In the AC withstanding voltage test method between terminals of gas insulated switchgear,
Two AC voltage generators for testing are used, the power supply voltage on the primary side of the AC voltage generator is shared, the connection is changed so that each has an opposite phase, and the opposite phase is between the terminals of the gas insulated switchgear. An AC withstand voltage test method, comprising applying an AC voltage to perform a withstand voltage test. 2. The AC withstanding voltage test method according to claim 1, wherein the gas-insulated switchgear has a capacitor connected in parallel with the terminals. Of the two test circuits consisting of two test AC voltage generators, one is a test circuit that can control the secondary output voltage by the voltage regulator regardless of the common primary power supply voltage. 3. The AC withstanding voltage test method according to claim 1, wherein the other is a test circuit that directly controls the secondary output voltage with a common primary power supply voltage. 4. A large-capacity generator capable of flowing a large current and having a variable output voltage is used as a primary side voltage source common to two AC voltage generators. The AC withstanding voltage test method according to any one of the above items. Compensation reactor that compensates for the primary power supply current to be minimized for a test circuit composed of one test AC voltage generator out of two test circuits composed of two test AC voltage generators 5. The AC circuit according to claim 1, wherein the test circuit that directly controls the secondary output voltage with the voltage of the other generator output does not include a compensation reactor. Withstand voltage test method. Of the two test circuits comprising two test AC voltage generators, a voltage source is provided on the primary side of the AC voltage generator of the test circuit that controls the output voltage value using one inductive voltage regulator. The voltage source is connected only to the test circuit on the side that controls the secondary side output voltage of the AC voltage generator with the other generator output without being connected. AC withstanding voltage test method according to item. In the AC voltage test device between the terminals of gas insulated switchgear with a capacitor connected in parallel with the internal terminal of the switch,
Two test AC voltages that apply a common power supply voltage on the primary side of each AC voltage generator to the two terminals of the switch and apply an AC voltage of opposite phase between the terminals so that they have opposite phases. Connect the generator,
Of the two test AC voltage generators, one is a test circuit that can control the secondary output voltage by a voltage regulator regardless of the common primary power supply voltage, and the other is a common primary. An AC withstanding voltage test apparatus characterized in that the test circuit directly controls the secondary output voltage with the power supply voltage on the side.

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