JPS595871B2 - Test method for breaker - Google Patents

Description

[Detailed Description of the Invention] The present invention verifies the shear breaking performance of shiitake and new fields used for generator circuit protection when the alternating current component of the generator's short-circuit current attenuates faster than the direct current component. This relates to test methods for

The short-circuit current of a generator with a short-circuit current in which the alternating current component attenuates faster than the direct current component does not have a current zero point for several tens of cycles from the instant of the short circuit, as shown in FIG.

In such circuits, it is known from various studies that the arc resistance of the shield cutter used in the circuit is quite effective in speeding up the attenuation of the DC component in the event of a short circuit. However, as shown in Figure 2, in the short-circuit current of a generator in an ordinary short-circuit test facility, the attenuation of the DC component is faster than the attenuation of the AC component. It is not possible to verify the shearing performance.

In addition, an equivalent short-circuit test circuit as shown in Figure 4 is generally used as an equivalent testing device for Nishiya Nitta, in which the main AC generator 1 and the auxiliary DC power supply 8 are connected in parallel to energize the test sample or Nitta T. However, even if such test equipment is used,
It is difficult to verify the shear breaking performance of shiyashinden against the deflected short-circuit current shown in FIG. 1 above. That is, in Fig. 4, the main alternating current generator 1 is connected to the test tank 7 via the current limiting reactor 2, the protection switch 3, the closing switch 4, the auxiliary switch 5, and the DC A parallel circuit is provided that connects the power supply 8 to the test sample and the test sample T via the auxiliary power source 6, and the composite short-circuit current as shown in Fig. 3 is generated by the main AC generator 1 and the auxiliary DC power source 8. Even if the Nitta T is energized, there is no problem until the short circuit current is cut off by the test or Nitta T, but after the short circuit current is cut off, the restart voltage,
Considering the current distribution circuits of the two power sources, the current of the auxiliary DC power source 8 must be cut off at the same time as the test sample and Nitta T.

However, it is very difficult to control this reliably, and furthermore, in order to quickly cut off the auxiliary DC power supply 8 at the auxiliary shiya new field 6 shown in Fig. 4, it is necessary to limit this DC current. It has to flow. In this case, the test sample or disconnector 7 limits the auxiliary DC power supply current before cutting off the composite short-circuit current, so it cannot be used as a verification test for the test sample or the disconnector 7. Therefore, this invention does not limit the auxiliary DC power supply current,
Furthermore, this direct current is cut off at the same time as the current in the test sample or disconnector is cut off, and the short circuit current as shown in Figure 1 is
The aim is to speed up the attenuation of the DC component, forcefully create a current zero point, and verify whether the short-circuit current is successful or not.

FIG. 5 shows a test circuit for this purpose. Next, referring to FIG. 5, its circuit configuration and testing method will be explained.

In a general short-circuit test circuit, a test circuit or disconnector 7 is connected to the main alternating current generator 1 via a current limiting reactor 2, a protective shield disconnector 3, a closing switch 4, and an auxiliary shield disconnector 5. However, in the present invention, another auxiliary alternator 12 is further used in parallel with the test sample and the disconnector 7, so that the current limiting reactor 1
1. Connect the auxiliary circuit via the protective shield breaker 10, the make switch 9, the large current transformer 15, and the rectifier 14.

In such a device, the alternating current generators 1 and 12 are synchronized with an arbitrary phase difference by a phase adjustment device 13, so by appropriately selecting the phase difference,
The zero point of the AC short-circuit current on the primary side of the large current transformer 15 caused by the AC generator 12 can be controlled to match the short-circuit current of the sample under test or the disconnector 7. Furthermore, by cutting off the AC short circuit current on the primary side of the large current transformer 15, the rectifier 1 on the secondary side of the large current transformer 15
Since the DC current obtained through the breaker 4 can be interrupted immediately, the DC current is not limited by the protective circuit breaker 10. Therefore, as shown in Figure 3, the test method is to turn on switches 4 and 9 almost simultaneously to supply a composite short-circuit current to the test sample or disconnector 7, and after several cycles, The primary side short-circuit current of the large current transformer 15 is discharged by the protector and disconnector 10 at the estimated short-circuit current of the test circuit and the disconnector 7. It can be verified whether the test sample or the disconnector 7 can quickly interrupt a short circuit current as shown in FIG.

As described above, according to the present invention, the auxiliary alternator is connected in parallel to the main alternator through the transformer and the rectifier, thereby easily reducing the resistance of the shield breaker to AC short-circuit current including the direct current component. This allows you to verify performance.

[Brief explanation of the drawing]

Figures 1 to 3 show three examples of current waveforms after a short circuit in an alternator. FIG. 4 shows an example of a short circuit test circuit that can supply the short circuit current shown in FIG. . In the figure, 1 is the main AC generator, 2 is the current limiting reactor, 7 is the test sample or disconnector, 8 is the auxiliary DC power supply, 12 is the auxiliary AC generator, 1
3 is a phase adjustment device, 14 is a rectifier, and 15 is a transformer.

Claims (1)

[Claims] 1 A first circuit that connects the main alternator to the test sample or disconnector via the current limiting reactor, the closing switch, the protective shield or the disconnector, and supplies an AC short-circuit current to the test sample or the disconnector, and the auxiliary AC A second circuit is connected from the generator to the test sample or disconnector through the current limiting reactor, closing switch, protective shield, disconnector, large current transformer, and rectifier, and supplies DC current to the test sample or disconnector.
circuit, and a phase adjustment device capable of synchronously operating the main alternator and the auxiliary alternator at an arbitrary phase difference; A test method for a shield breaker, characterized in that a synthetic short circuit current is applied to open the protective shield or breaker of the second circuit simultaneously with the opening of the test circuit or breaker.