Low damping alternating-current high-voltage generator for detecting power equipment local discharge

Abstract

The invention discloses a low damping alternating-current high-voltage generator for detecting power equipment local discharge. The low damping alternating-current high-voltage generator comprises a high-power direct-current power supply connected with an alternating-current power supply, a high-voltage semiconductor switch connected with the direct-current power supply, an electric reactor unit connected with the high-voltage semiconductor switch, a resistance-capacitance divider parallelly connected with the electric reactor unit, and a capacitor unit parallelly connected with the resistance-capacitance divider. The low damping alternating-current high-voltage generator has the advantages that inductance equipment such as transformers and electric reactors can replace the electric reactor unit directly, or capacitors of large-capacity testing objects such as power cables can replace the capacitor unit, and local discharge detection can be performed on various power equipment by adjusting the inductor and capacitor elements in the main LC resonance circuit of the generator; the whole generator belonging to lossless local discharge low damping alternating-current high-voltage detecting devices is light, reliable in operation, high in safety, and the like; the generator is applicable to local discharge detection of various capacitance and inductance equipment, and suitable for field detection of various power equipment such as transformers, electric reactors, capacitors and cables.

Description

technical field [0001] The invention relates to a technology for detecting the insulation state of electric equipment and its application field, in particular to a high-voltage weakly damped AC voltage generator for partial discharge detection of electric equipment. Background technique [0002] Partial discharge detection and positioning test are important contents of on-site handover test and condition maintenance of power cables. For power equipment with a large capacitance, the volume and weight of the power frequency high-voltage power supply required for field tests are usually large, and transportation is difficult, making it difficult to meet the needs of field tests. In recent years, an advanced damped AC voltage testing technology has been more and more widely used in electric power enterprises. This kind of equipment is portable, easy to operate, has good equivalence with power frequency AC voltage, and is suitable for field tests of various large-capacity power ...

AI Technical Summary

Problems solved by technology

[0003] However, the current damped AC voltage test technology still has several technical problems to be solved in practical application: 1) The high-voltage semiconductor switch, the key component of the damped AC voltage generator, is in the LC series resonant circuit, and the current flow capacity of the semiconductor switch Restricts the further popularization and application of oscillatory wave testing technology

At the same time, the performance of the switch and its auxiliary circuits will also affect the oscillation waveform and the test effect; 2) The traditional damped AC voltage test system needs to use a high-voltage DC power supply to charge the main circuit capacitor and the device under test during the test, which makes the test The equipment has to withstand DC high voltage for a long time before being subjected to the damped oscillatory wave, which affects the equivalence of the damped oscillatory wave voltage and the partial discharge test results of the power frequency AC voltage

3) The traditional topology requires that the damped AC voltage test system must have a high-voltage DC power supply, and both ends of the air-core reactor need a high insulation design. These factors also increase the size and weight of the existing test equipment and reduce the device portability

4) The traditional damped AC voltage test system is only suitable for power equipment with large capacitance, and partial discharge testing cannot be carried out for low capacitance or inductive equipment

Images