JPH0461312B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for verifying the advanced small current shearing performance of a shield breaker, particularly the advanced small current shearing performance of a shield breaker using a long-wave tail impulse voltage generator. Regarding the verification method.

The equivalent circuit for the verification test of the advanced small current shear breaker performance of the conventional sheath breaker was as shown in Figure 1. That is, a test sample or disconnector 3 is connected between the AC power source 1 and the capacitor 2. The alternating current 1 includes 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 test 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 shearing performance of a shunt breaker without using a short-circuit generator.

The present invention uses an impulse voltage generator with a wave tail length of 10 ms or more in order to verify the advanced small current shearing performance of the shedding breaker without using a short-circuit generator. In other words, after opening the breaker, a long-wavelength impulse voltage is applied, and with a single application, the dielectric breakdown voltage between the electrodes of the breaker during opening operation can be obtained at multiple points. be. Impulse voltage is 10ms
Because of the above long wave tail, breakdown voltages at multiple points can be obtained at once.

Here, the wave tail length is defined as the time between the (conventional) origin of the impulse voltage wave and the half-wave high point of the wave tail of the impulse voltage. (Showa
July 15, 1951), pages 38 to 40 and pages 78 to 78
See page 79. For switching impulse voltage, it is also called half-wave height time. ) An embodiment of the present invention will be described below with reference to FIG. The long wave tail impulse voltage generator 10 of 10 ms or more has positive and negative polarity DC charging power sources 11, 1.
2, charging resistors 13, 14, charging switch 15,
It is composed of a capacitor 16, a neutral point resistor 17, a discharge gap 18, and a wave length adjustment resistor 19. An electric trigger electrode 2 is installed in the lowest discharge gap 18.
0 and a trigger generator 21 are provided.

The operating principle of this impulse voltage generator 10 is described in the above-mentioned "Insulation Test Method Handbook", page 40.
As described on pages 65 and 81 to 88, the multistage capacitor 16 is charged and the discharge gap 18 is
This is almost the same as the conventional device that generates high voltage by connecting charged capacitors 16 in series using The difference is that the value of the resistor 19 is increased and a charging 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 sample or disconnector 3 is connected to the capacitor 23 directly or via a certain impedance. Even if they are directly connected, residual inductance 24 and resistance 25 exist as shown in FIG.

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

Assume that the characteristics of the distance l between poles of the test sample and the disconnector 3 with respect to time t are as shown in FIG. The distance l between poles in a completely open state is L ₀ . Assume that the time characteristic of the dielectric breakdown voltage between the electrodes during the test or during opening of the disconnector 3 is 30 in FIG.

The gap between the poles begins to open at time T ₁ , and when a long wave tail impulse voltage of 10 ms or more is applied at time T ₂ , first
At P ₁ , dielectric breakdown occurs between the electrodes. After dielectric breakdown, the charge of 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 Figure 5, and the current zero point is obtained. It will be done. Here, the insulation of the shield breaker 3 is restored, and voltage is applied again from the long-wave tail impulse voltage generator, and as shown in Figure 4, the voltage _S2 is applied to the shield breaker 3, causing dielectric breakdown at _P2 . become.

Then the same phenomenon is obtained repeatedly, P ₃ ~ _{P 6}
Dielectric breakdown occurs as in By connecting P ₁ to _{P 6} , the time characteristics of the breakdown voltage between the electrodes can be obtained. In other words, if a normal impulse voltage generator is used, only one measurement point, such as P ₅ , can be obtained, but with this embodiment, multiple measurement points P ₁ to _{P 6} can be obtained at one measurement point. It is obtained by applying an impulse voltage of 2 times. Here, the longer the wave tail length of the impulse voltage is, the better; however, a minimum of 10 ms is required since the advanced small current shear breaker performance is determined by the characteristics in the region of 10 to 40 ms from the start of contact opening.

According to this embodiment, a long-wave tail impulse voltage generator of 10 ms or more can be used for the verification test of advanced small current shearing performance of the shingle breaker. Dielectric breakdown voltage characteristics can be determined at multiple points.

FIG. 6 is a circuit diagram according to another embodiment of the present invention. In FIG. 2, one side of the test sample or disconnector is grounded, but in FIG. 6, a DC voltage of opposite polarity to the long-wave tail impulse voltage is applied. A DC high voltage power supply 40 is connected to one side of the shield breaker 3 via a resistor 41 and a capacitor 42.

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

As described above, according to the present invention, a long-wave tail impulse voltage of 10 ms or more is applied to the other end of the test sample or disconnector after the start of opening, and a small current flows through the test sample or disconnector. Since it is possible to verify the disconnection performance of the test specimen or disconnector, there is no need to use a conventional short-circuit generator. The insulation voltage can be verified at multiple points. As a result, test equipment becomes cheaper and
Breakdown voltages at multiple points can be obtained at once, significantly reducing test time.

[Brief explanation of the drawing]

Figure 1 is an equivalent circuit for verifying the advanced small current shield breaking performance of a conventional shield breaker, Figure 2 is an equivalent circuit for testing using a long wave tail impulse voltage generator to which the method of the present invention is applied, and Figures 3 to 5 6 is a diagram explaining the operating principle of the present invention, and FIG. 6 is a test equivalent circuit according to a modification of the present invention. 3...Shiya disconnector, 15...Charging switch, 1
6...Capacitor, 18...Discharge gap, 19
...Wavelength tail adjustment resistance, 22...Wavelength adjustment resistance,
23... Capacitor.

Claims (1)

[Claims] 1. In the case of verifying the progress of a test sample or disconnector's small current shedding performance, one end of the test sample or disconnector is grounded or a DC voltage is applied, and the other end of the test sample or disconnector is grounded or a DC voltage is applied. An impulse voltage generator connected to the circuit generates an impulse voltage with a wave length of 10 ms or more, which is related to the interelectrode dielectric breakdown characteristics during opening of the circuit breaker, after the test sample or circuit breaker begins to open. At the same time, the electric charge of a capacitor whose one end is connected between the other end of the test sample or disconnector and the impulse voltage generator and the other end is grounded is caused by dielectric breakdown between the electrodes of the test sample or disconnector. A method for verifying the progressing small current breaker performance of a breaker, characterized in that an oscillatory discharge current is discharged between the poles of the test sample or breaker after each test.