Special withstand voltage testing device and method for power capacitor

Abstract

The invention discloses a special withstand voltage testing device and method for a power capacitor. The special withstand voltage testing device comprises a power supply, a voltage regulator, a transformer and a serial-parallel resonant circuit which is arranged at the other side of the transformer and corresponds to the voltage regulator; the serial-parallel resonant circuit comprises a serial compensation reactor, a parallel compensation reactor, a wave-modulating resistor, a silicon controlled rectifier trigger control device, a high voltage divider and a digital storage oscilloscope, wherein the serial compensation reactor is serially connected with a testing capacitor; the parallel compensation reactor is connected in parallel with the testing capacitor; the wave-modulating resistor is connected in series in the circuit; the silicon controlled rectifier trigger control device is connected with the wave-modulating resistor; the high voltage divider and the digital storage oscilloscope are connected at two electrodes of the testing capacitor; and the serial-parallel resonant circuit is grounded. The testing method provided by the invention has the benefits that: (1) the problem of slower voltage boosting of the general voltage regulator is solved by using a method for instantaneously changing a resonant parameter to generate a high voltage; (2) the time of withstanding a high voltage on a test product can be precisely controlled by controlling the on time of a silicon controlled rectifier; and (3) the test voltage is controlled precisely and the oscilloscope can be simultaneously triggered to collect test waveforms.

Description

technical field [0001] The invention relates to a power capacitor, in particular to a special withstand voltage test device and a test method for a power capacitor. Background technique [0002] Among all electrical equipment, the insulation working field strength of power capacitors is the highest. In the power transmission and transformation industry, in order to reduce the output and reactive power conversion of generators and transformers, and reduce the power loss of the power system, parallel power capacitor banks are generally used; in order to increase the transmission capacity of transmission lines, series compensation capacitor banks are generally used. Due to the special operating environment requirements of the series compensation device, special test items are required for the series compensation capacitor, one of which is to apply 1.35 U lim Power frequency voltage, continuous withstand time 300ms ~ 500ms. The characteristics of this test project are: high ...

AI Technical Summary

Problems solved by technology

If a conventional motor is used to control the boosting method of the coil of the voltage regulator, the boosting speed is generally 200V / s~500V / s, and the voltage rises to 1.35 from the time the switch is closed. U lim The required boost time may exceed the continuous tolerance time required by the test, and the continuous tolerance time cannot be precisely controlled

This method is difficult to meet the test requirements and truly reflect the actual withstand voltage level of the test product

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