JPH05113470A - Short-circuit testing device for breaker - Google Patents

Abstract

PURPOSE:To obtain the titled device capable of carrying out the cutoff test of an asymmetrical alternating current. CONSTITUTION:The first and second current source capacitors Ci1 and Ci2, and the first and second current source reactors Li1 and Li2 are provided in a current source circuit 1. The first resonance circuit is constituted of the capacitor Ci1 and the reactor Li1, and the second resonance circuit by the capacitor Ci2 and the reactor Li2. The resonant frequency of the first circuit is set about two times of one of the second circuit, their frequencies are used as test frequencies, and the oscillating currents of the first and second circuits are superposed and supplied to a breaker Sp to be tested.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short circuit tester for a circuit breaker which conducts a synthetic short circuit test on the circuit breaker.

[0002]

2. Description of the Related Art In the synthetic short circuit test method specified in JEC-2300, a current source circuit for supplying a short circuit current to a circuit breaker under test and a voltage source circuit for supplying a transient recovery voltage and a recovery voltage are provided. After connecting the current source circuit to the circuit breaker under test and passing a short-circuit current through the circuit breaker, connect the voltage source circuit to the circuit breaker under test immediately before the zero point of the short-circuit current, and change the short-circuit current from the current source circuit to the voltage. Superimpose the current from the source circuit.

As a test device used in the synthetic short-circuit test method,
The device shown in FIG. 4 is known. In the figure, Ei is a current source charger consisting of a high-voltage DC power source, and the output voltage of this charger is the current source capacitor C via the switches S1 and S1 '.
applied to i. One end of the capacitor Ci is grounded, and one end of the current source reactor Li is connected to the non-grounded terminal of the capacitor Ci via the switch S2, the protective breaker BS and the closing switch MS. Reactor Li
The other end of is connected to one end of the auxiliary circuit breaker Sn, and the test circuit breaker Sp is connected between the other end of the auxiliary circuit breaker Sn and the ground. An arc extender Pa is connected between the connection point between the reactor Li and the auxiliary circuit breaker Sn and the ground. Ev is a voltage source charger composed of a high-voltage DC power source, and the output voltage of this charger is the voltage source capacitor Cv via the switches S3 and S3 '.
Is being applied to. One end of the voltage source capacitor Cv is grounded via a discharge gap G1 having a trigger electrode g,
The other end of the voltage source capacitor Cv is connected to one end of the voltage source reactor Lv via the discharge gap G2. The other end of the reactor Lv is connected to the non-grounded side terminal of the test circuit breaker Sp, and the transient recovery voltage adjusting resistor Re and the transient recovery voltage adjusting capacitor Ce are connected between the other end of the reactor Lv and the ground.
And a series circuit with is connected. A current transformer CT for detecting a short circuit current flowing through the circuit breaker under test is provided.
The output of T is a current zero detector DET for detecting the current zero.
Is being supplied to. The current zero detector DET is adapted to generate a trigger voltage when the zero of the current is detected, and this trigger voltage is supplied to the trigger electrode g.

In this example, the current source charger Ei, the switches S1 and S1 ', the current source capacitor Ci, and the switch S1.
2, the protection circuit breaker BS, the closing switch MS, the current source reactor Li and the auxiliary circuit breaker Sn.
Is configured. Also, the voltage source charger Ev, the switches S3 and S3 ', the discharge gaps G1 and G2, and the resistor Re
The voltage source circuit 2 is composed of the capacitor Ce and the capacitor Ce.

The resonance frequency of the series resonance circuit composed of the current source capacitor Ci and the current source reactor Li is set to the commercial frequency (50 Hz or 60 Hz). Similarly, the resonance frequency of the series resonance circuit constituted by the voltage source capacitor Cv and the voltage source reactor Lv is also set to the commercial frequency.

When the circuit breaker is tested by using the above short circuit tester, the switches S1 and S1 'are first closed for a certain period of time to charge the current source capacitor Ci. Then switch S
3 and S3 'are closed for a certain period of time to charge the voltage source capacitor Cv.

After the charging of the capacitors Ci and Cv is completed, the protective breaker BS and the auxiliary breaker Sn are closed, and a closing command is given to the closing switch MS. As shown in FIG. 5A, when the closing switch MS is closed at time to, the current source capacitor Ci starts discharging through the reactor Li and the test breaker Sp. At this time, resonance occurs in the resonance circuit composed of the capacitor Ci and the reactor Li, and as shown in FIG. 5 (A), the discharge current I that attenuates and oscillates at the commercial frequency flows through the test breaker Sp. After this discharge current flows, the test breaker Sp is opened at time t1 (opening time). Circuit breaker Sp
If the current is cut off successfully, the current is cut off at the current zero point appearing immediately after the opening time t1 or at the current zero point t2.

The trigger device DET detects the position immediately before the zero point of the current flowing through the circuit breaker from the output of the current transformer CT, and applies a pulsed trigger voltage to the trigger electrode g at the position immediately before the detected current zero point. give. When a trigger voltage is applied to the trigger electrode g, a discharge is generated in the discharge gap G1 and a discharge is generated in the discharge gap G1. As a result, the voltage source capacitor Cv is connected to the reactor Lv, and the capacitor Cv is connected to the reactor Lv.
A current flows through the test breaker Sp through v. When this current is cut off, the transient recovery voltage and the recovery voltage are applied between the poles of each phase of the test breaker Sp.

The arc extender Pa outputs a pulse voltage for extending the arc between the poles of the circuit breaker Sp under test when a current zero is detected from the output of the current transformer CT.

[0010]

The conventional short-circuit test device can only perform the breaking test of the symmetrical current I as shown in FIG. 5 (A), and the asymmetrical current I'shown in FIG. 5 (B). Asymmetrical AC current interruption tests such as a major loop interruption for interruption and a minor loop interruption for asymmetrical current I ″ shown in FIG. 5C could not be conducted.

An object of the present invention is to provide a short-circuit test device for a circuit breaker, which can also perform a breaking test of an asymmetrical alternating current.

[0012]

The present invention provides a current source circuit for supplying a short circuit current for a synthetic short circuit test to a circuit breaker under test,
The present invention relates to a short circuit tester for a circuit breaker, which comprises a circuit breaker under test and a voltage source circuit for supplying a transient recovery voltage and a recovery voltage for a composite short circuit test.

In the present invention, the first and second current source capacitors and the first and second current source capacitors are respectively connected in series to the current source circuit, and the first and second current source capacitors are connected in series.
And the first and second reactors forming the first and second resonance circuits together with the second current source capacitor, so that the resonance frequency of the first resonance circuit is substantially equal to the resonance frequency of the second resonance circuit. The oscillating currents of the first and second resonance circuits are superposed and supplied to the circuit breaker under test.

[0014]

As described above, the first and second resonance circuits are provided in the current source circuit, and the resonance frequency of the first resonance circuit is set to be approximately twice the resonance frequency of the second resonance circuit to set the test frequency. By superposing the oscillating current flowing through both resonance circuits and supplying it to the circuit breaker under test, the current flowing through the circuit breaker under test can be made to have an asymmetrical waveform, so an asymmetrical AC current breaking test is performed. be able to.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention. In FIG. 1, parts equivalent to those of the conventional test circuit shown in FIG. In this example,
The configuration of the voltage source circuit 2 is exactly the same as that of the conventional test device shown in FIG.

In the present invention, the current source circuit 1 has a first
Current source capacitor Ci1 and second current source capacitor Ci2
Are provided, and one ends of these capacitors are grounded. The non-grounded terminal of the capacitor Ci1 is a switch S11.
Is connected to one end of the current source charger Ei through a diode D1 and a diode D1.
It is connected to one end of a current source charger Ei through 12 and a diode D2. The other end of the current source charger Ei is grounded through the switch S1 '.

The non-grounded side terminal of the first current source capacitor Ci1 is also connected to one end of the first current source reactor Li1 through the switch S21, and the second current source capacitor Ci2.
The non-ground side terminal of is connected to one end of the second current source reactor Li2 through the switch S22. The other ends of the first and second current source reactors Li1 and Li2 are commonly connected,
It is connected to the protective circuit breaker BS. The first current source capacitor Ci1 and the first current source reactor Li1 form a first resonance circuit, and the second current source capacitor Ci2 and the second current source reactor Li2 form a second resonance circuit. Has been done. The resonance frequency of the first resonance circuit is set to twice the resonance frequency of the second resonance circuit, and the vibration current obtained as a result of combining the vibration current of the first resonance circuit and the vibration current of the second resonance circuit The frequency of is equal to the commercial frequency. Other points are the same as those of the conventional test apparatus shown in FIG.

When performing the asymmetrical AC interruption test of the circuit breaker by using the above-mentioned short circuit test apparatus, first, the switches S11 and S1 '
And are closed for a certain period of time to charge the first current source capacitor Ci1. Then, the switches S12 and S1 'are closed for a certain period of time to charge the second current source capacitor Ci2. After that, the switches S3 and S3 'are closed for a certain period of time to charge the voltage source capacitor Cv.

After the charging of the capacitors Ci1, Ci2 and Cv is completed, the switches S21 and S22 are closed, and further the protective breaker BS and the auxiliary breaker Sn are closed, and then the closing switch M is closed.
Give a close command to S. When the closing switch MS is closed at time t0, the first current source capacitor Ci1 is connected to the reactor Li1.
And the circuit breaker Sp under test, and the second power supply capacitor Ci2 is discharged through the reactor Li2 and the resonance circuit breaker Sp. At this time, resonance occurs in the first resonance circuit formed of the capacitor Ci1 and the reactor Li2 and the second resonance circuit formed of the capacitor Ci2 and the reactor Li2.
As shown in FIG. 3, the oscillating current i1 flows through the first resonant circuit, and the oscillating current i2 having a frequency half that of the oscillating current i1 flows through the second resonant circuit. Since the currents i1 and i2 flow through the test circuit breaker Sp in a superimposed manner, the waveform of the current flowing through the test circuit breaker Sp has an asymmetrical waveform like the current i1 + i2 in FIG.

As described above, since an AC current having an asymmetrical waveform flows through the circuit breaker under test, a predetermined asymmetrical AC current interruption test can be performed by selecting a portion of the asymmetrical current having a predetermined waveform. It can be carried out. For example, by giving a breaking command to the test breaker Sp at time t1 'in FIG. 3, a major loop break test as shown in FIG. 5 (B) can be performed, and at time t1 "in FIG. 5C, it is possible to perform a minor loop break test, where t2 'is the cutoff completion time when the major loop cutoff is successful, and t2 ".
Is the cutoff completion time when the minor loop cutoff is successful. Since the operation of the voltage source circuit 2 is the same as the conventional one, the description thereof will be omitted.

In the above description, the first and second current source capacitors Ci1 and Ci2 are sequentially charged, but if the capacity of the current source charger Ei is sufficient, the switch S
11 and S12 may be closed at the same time to charge the capacitors Ci1 and Ci2 at the same time.

In the above embodiment, the first and second current source capacitors Ci1 and Ci2 are charged to the same polarity. However, as shown in FIG. 2, the current source charger Ei and the first and second current sources are connected to each other. A changeover switch SW1, between the capacitors Ci1 and Ci2,
SW1 'may be provided to charge the first and second current source capacitors in opposite polarities.

[0023]

As described above, according to the present invention, the first and second resonant circuits are provided in the current source circuit and the first and second resonant circuits are provided.
Since the resonance frequency of the resonance circuit of 2 is set to be approximately twice the resonance frequency of the second resonance circuit as the test frequency, and the oscillating current flowing through both resonance circuits is superimposed and supplied to the circuit breaker under test, The current flowing through the circuit breaker under test has an asymmetrical waveform, which is advantageous in that a breaking test of an asymmetrical alternating current can be performed.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a main part of another embodiment of the present invention.

FIG. 3 is a waveform diagram showing a waveform of a current flowing through a current source circuit in the embodiment of FIG.

FIG. 4 is a circuit diagram showing a configuration of a conventional test circuit.

5A to 5C are waveform diagrams showing different breaking current waveforms.

[Explanation of symbols]

1 ... Current source circuit, 2 ... Voltage source circuit, Ei ... Current source charger, Ci1 ... First current source capacitor, Ci2 ... Second current source capacitor, Li1 ... First current source reactor, Li2 ...
Second current source reactor, Sp ... Test breaker, Ev ... Voltage source charger, Cv ... Voltage source capacitor, Lv ... Voltage source reactor.

Claims (1)

[Claims] 1. A current source circuit for supplying a short circuit current for a composite short circuit test to the circuit breaker under test, and a voltage source circuit for supplying a transient recovery voltage and a recovery voltage for a composite short circuit test to the circuit breaker under test. In the short circuit tester for circuit breaker, the current source circuit is connected in series to the first and second current source capacitors and the first and second current source capacitors, and the first and second current source capacitors are connected in series. And a first and a second reactor forming a first and a second resonance circuit together with the current source capacitor, and superimposing an oscillating current of the first and the second resonance circuit on the test breaker. A short circuit tester for a circuit breaker, characterized in that the resonance frequency of the first resonance circuit is set to be approximately twice the resonance frequency of the second resonance circuit.