JPS6012587B2 - Switchgear durability test equipment - Google Patents

Description

[Detailed description of the invention] The present invention relates to a durability testing device for a switch.

For example, in a so-called frequent opening/closing Z device, such as a switch for a condenser bank, which opens and closes several times a day under actual use conditions, it is necessary to conduct an opening/closing durability test tens of thousands of times with a full load. This test is possible to some extent by using a so-called short-circuit generator and a capacitor bank. However, from a practical point of view, it is extremely wasteful to use a short-circuit generator only for opening/closing tests over tens of thousands of times, and it cannot be said to be a sufficient test in terms of performance. For this reason, some kind of equivalent test device that can replace the short-circuit generator is required.

The problem with equivalent test equipment that uses this kind of high pressure is
It can be said that the question lies in how to actually achieve usage conditions close to 2. First, let's take a look at the actual usage conditions. FIG. 1 shows switching current waveforms when a condenser bank is opened and closed by a switch in an actual system, but the diagram only shows one phase of the three-phase current for convenience. In the same figure, if the switch is closed at the closing point, the closing current flows due to the preceding arc before the contacts of the switch make mechanical contact.The closing current continues after the contacts make contact. It is superimposed on the flowing AC current with a frequency of about 200Hz.The size of this transient current is 4 to 5 times larger than the AC current, and when using a large capacity capacitor bank, it also has a frequency of about 200Hz. The arc extinguishing chamber is consumed by the generation of such a transient current.On the other hand, when the switch is cut off, an arc is generated at the same time as the contact is opened, and then at the zero current point, that is, the cutoff point. The current in the cosodenser bank at that time is at most IKA, and it is also a leading power factor, so the arc time (opening point to breaking point) does not exceed 0.5 cycles.The above is the actual system. These are the terms of use.

Therefore, the present invention provides a switch durability testing device that can perform a durability test of the opening/closing operation of a switch under conditions closest to such usage conditions. FIG. 2 is a circuit diagram showing one embodiment of the present invention.

In the figure, 1 is an AC power supply, 2 is a capacitor connected to this AC power supply 1 via a resistor 3 and a rectifier 4, and its capacitance value is made equal to the value of one phase of the capacitor bank in the actual system. . 5 is a first reactor connected to one end of this capacitor 2, and this also has an inductance of the same value as the series reactor used in the actual capacitor bank.

6 is a first auxiliary switch connected in series with this first reactor S, and 7 is two fixed saddle points a? The other end of the first auxiliary switch 6 is connected to its fixed contact a.

Is one end of 8 a switching disconnector? This is a test switch whose terminal is connected to the movable contact c of the capacitor 2 and whose terminal end is connected to the other end of the capacitor 2.

Further, reference numeral 9 denotes a transformer having an AC power source 10 connected to its primary side, and one end of its secondary side being the capacitor 2 of the test switch 8.
The end of the switch is connected to another fixed contact b of the switch/disconnector mist through a predetermined second reactor switch and second auxiliary switch switch 2. Next, the operation of this embodiment will be described. The first auxiliary switch 6 is open, and the second auxiliary switch 2 and the side of the secondary switch are open.With the switching disconnector closed and the fixed contact A side turned over, the capacitor 2 is charged to a voltage of E. .E is the phase voltage peak value of the actual system. After charging capacitor 2, the test switch base is turned on. Then ~
This test switch 8! A transient current as shown in Fig. 3 flows, but this is simply the alternating current component removed from the input current waveform of the actual system shown in Fig. 3. That is, although the pre-arc time of the switch is shorter than the time required for the AC current to become sufficiently large, it can be said that even if the AC power source component during the pre-arc time is missing, the two are equivalent in terms of energy. Immediately after the test switch 8 has been turned on, the first auxiliary switch 6 is opened. This is to limit the discharging of the charge in the capacitor 2 to the minimum necessary level and to facilitate repeated charging. Further, following the interruption of the first auxiliary switch 6, the sliding door disconnector 7 is moved to the opposite contact b side, and the second
Insert the auxiliary switch turtle 2 and open the 2nd reactor military wealth - 2nd
A current of the same value as the commercial frequency capacitor current of the actual system is passed through the circuit of the auxiliary switch switch 2 - the test switch 8, and the mysterious switch is cut off. In that case, even if the voltage E2 on the secondary side of the t-transformer 9 is selected to be considerably lower than that of the actual system due to equipment considerations, the arcing time of the switch at this time is 0.5 cycles as described above. Since it is as follows, the arc energy when the switch is cut off can be made equivalent to the actual system. That is, the arc energy when the switch is cut off is different from that when it is turned on, and can be easily achieved with a low voltage power source with a lag power factor. By repeating the above operation a necessary number of times and checking the insulation recovery characteristics of the test switch as needed during the process using a predetermined test method, it is possible to carry out a reliable durability test of the test switch.

Note that the first auxiliary switch 6 can be omitted.

As described above, according to the present invention, not only can the transient current at the time of closing, which is an important element in the durability test of this kind of switch, be realized in the most realistic form, but also the current at the time of breaking the switch can be realized in an actual manner. This can be achieved, so to speak, it is possible to reliably test the durability of the switch.

Furthermore, as can be seen from the fact that the test equipment does not use a short-circuit generator, it has excellent effects such as low production costs and low test implementation costs. FIG. 2 is a waveform diagram showing the flowing switching current waveform, FIG. 2 is a circuit diagram showing one embodiment of the present invention, and FIG. 3 is a waveform chart showing the operation thereof.

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... Rectifier, 8... First reactor, 6... First
Auxiliary switch y... W switching disconnector, 8... Test switch,
9...Trance: Takashi 1...Second reactor: Turtle 2...
Second auxiliary switch. *Figure 1: fins, scales, scales: 3

Claims (1)

[Claims] 1. A capacitor with a predetermined capacitance value charged to a predetermined voltage value, and a first reactor with a predetermined inductance value connected between both ends of the capacitor together with a test switch;
A first disconnector inserted into the discharge circuit of the capacitor consisting of the test switch and the first reactor, and a second disconnector and a second reactor having a predetermined inductance value in the test switch. A durability test device for a switch having an AC power source connected to the switch via the AC power supply for supplying a predetermined current to the switch under test.