JPS58182569A - Verifying method of small leading current breaking performance of circuit breaker - Google Patents

Abstract

PURPOSE:To obtain an interelectrode dielectric breakdown voltage of a circuit breaker under operation in opening state at plural points, by applying one shot of impulse voltage with a >=10ms long trailing edge once after the breaker is opened. CONSTITUTION:To obtain a >10ms long trailing edge, at an impulse voltage generating device 10, the values of a neutral point resistance 17 and a trail edge adjusting resistance 19 are made large, and the device 10 is provided with a charging switch 15, and after an capacitor 16 is charged up to a specific voltage, the opening point of the switch 15 is made different. When electrodes start parting at time T1 and a impulse voltage with a >=10ms long trailing edge is applied at time T2, an interelectrode dielectric breakdown occurs at point P1. If a discharging circuit is oscillatory, a discharging current is oscillatory and a current zero point is obtained. Then, a circuit breaker 3 obtains dielectric recovery and the voltage is applied again from the generating device for the impulse voltage with the long trailing edge to apply a voltage shown by point S2 to the breaker, causing a dielectric breakdown shown by point P2. Then, dielectric breakdowns occur similarly as shown by points P3-P6 to obtain plural measurement points by applying one shot of the impulse voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for verifying the advanced small current interrupting performance of a circuit breaker, and more particularly to a method for verifying the advanced small current interrupting performance of a breaker using a long-wave tail impulse voltage generator.

The equivalent circuit for verification testing of the advanced small current breaking performance of a conventional circuit breaker is shown in Figure 1. That is, a test breaker 3 is connected between the AC power supply 1 and the capacitor 2. The AC power supply 1 includes an internal impedance 4 such as a generator and a transformer.

When conducting a test as shown in FIG. 1, a generator is used, which has the disadvantage of requiring a large amount of testing cost and time for circuit configuration.

SUMMARY OF THE INVENTION An object of the present invention is to provide a test method for testing the advanced small current breaking performance of a circuit breaker without using a short-circuit generator.

The present invention uses an impulse voltage generator with a wave length of 10 ms or more in order to verify the advanced small current breaking performance of the breaker without using a short-circuit generator. That is,
After opening the circuit breaker, a long wave tail impulse voltage is applied, and with one application, the interelectrode breakdown voltage of the circuit breaker in operation is obtained at multiple points. Since the impulse voltage has a long wave tail of 10 ms or more, breakdown voltages at multiple points can be obtained at once.

An embodiment of the present invention will be explained below with reference to FIG.

The long wave tail impulse voltage generator 10 of 10 ms or more is
Positive and negative polarity DC charging power supplies 11, 12, charging resistor 1
3, 14, a charging switch 15, a capacitor 16, a neutral point resistor 17, a discharge gap 18, and a wave length adjustment resistor 19. An electric trigger electrode 20 and a trigger generator 21 are provided in the discharge gap 18 at the lowest stage.

The operating principle of this impulse voltage generator 10 is almost the same as that of the conventional device, but in order to obtain a long wave tail of 10 ms or more, the value of the neutral point resistor 17 and the value of the wave length adjustment resistor 19 are increased, and the charging The difference is that a switch 15 is provided and the switch 15 is opened after charging the capacitor 16 to a predetermined voltage.

The wavefront length of the impulse voltage can be controlled by the values of the wavefront adjustment resistor 22 and capacitor 23 that are attached externally.

The test breaker 3 is connected to the capacitor 23 either directly or via a certain impedance. Even if you connect directly, the second
As shown in the figure, a residual inductance 24 and a resistance 25 are present.

The operating principle of the present invention is shown in FIG.

Assume that the characteristic of the distance l between poles of the test circuit breaker 3 versus time t is as shown in FIG. The distance l between poles in a completely open state is Lo. It is assumed that the time characteristic of the dielectric breakdown voltage between the electrodes during opening of the test circuit breaker 3 is 30 in FIG.

The gap between the electrodes begins to open at time T1, and when a long wave tail impulse voltage of 10 ms or more is applied at time T2, the gap between the electrodes first undergoes dielectric breakdown at P1. After dielectric breakdown, the charge in the capacitor 23 is discharged through the circuit breaker 3, but if the discharge circuit is made oscillatory, the discharge current becomes oscillatory as shown in FIG. 5, and a current zero point is obtained. Here, the breaker 3 recovers its insulation, and voltage is applied again from the long wave tail impulse voltage generator, and as shown in FIG. 4, the voltage S2 is applied to the breaker 3, causing dielectric breakdown at P2.

After that, the same phenomenon is repeatedly obtained, and dielectric breakdown occurs as shown in P3 to P6. By connecting P1 to P6, the time characteristics of the dielectric breakdown voltage between the electrodes can be obtained. That is, if a normal impulse voltage generator is used, only one measurement point, such as P5, can be obtained, but if it is used as in this embodiment,
A plurality of measurement points P1 to P6 are obtained by applying one impulse voltage. Here, the longer the wave tail length of the impulse voltage is, the better; however, since the advance small current breaking performance of the breaker is determined by the characteristics in the region of 10 to 40 ms from the start of opening, a minimum of 10 ms is required.

According to this embodiment, a long wave tail impulse voltage generator of 10 ms or more can be used for the verification test of the advanced small current breaking performance of the breaker, so that multiple dielectric breakdown voltage characteristics between the breaker poles can be measured by applying a single impulse voltage. You can find points.

FIG. 6 is a circuit diagram according to another embodiment of the present invention. Second
In the figure, one side of the test breaker is grounded, but in Figure 6, a DC voltage of opposite polarity to the long wave tail impulse voltage is applied. DC high voltage power supply 40 is resistor 41,
It is connected to one side of the breaker 3 via a capacitor 42.

In this example, the circuit conditions are more similar to the test for the small lead current of the circuit breaker.

According to the present invention, a long-wave tail impulse voltage generator of 10 ms or more is used for the verification test of the advanced small current breaking performance of the breaker, so there is no need to use a short-circuit generator that incurs a large amount of testing costs. .

[Brief explanation of drawings]

Fig. 1 shows an equivalent circuit for verifying the advanced small current breaking performance of a conventional circuit breaker, Fig. 2 shows an equivalent circuit for testing using a long-wave tail impulse voltage generator to which the method of the present invention is applied, and Figs. FIG. 6, which is a diagram explaining the operating principle, is a test equivalent circuit according to a modification of the present invention. 3... Breaker, 15... Charging switch, 1
6... Capacitor, 18... Discharge gap, 1
9...Wavelength tail adjustment resistor, 22...Wavelength adjustment resistor, 23...Capacitor. Agent Patent Attorney Takahashi ■

Claims (1)

[Claims] 1. Ground one end of the breaker or apply a DC voltage, and connect it to the other end for 10 m after the breaker starts to open.
1. A method for verifying the advanced small current breaking performance of a circuit breaker, the method comprising applying an impulse voltage with a long wave tail of s or more to obtain interpole dielectric breakdown characteristics of the circuit breaker during closing.