20kV振荡波测试系统的研制

Development of a 20kV Damped Oscillating Voltage Generator

本文研制了一种可用于6/10kV电缆局部放电测量的20kV阻尼振荡波测试系统,并提出一种新型的基于IGBT(Insulated Gate Bipolar Transistors)串联的高压开关结构,其由多路IGBT串联组成,集成于一个直径为60cm的圆形印刷电路板上。为了增强本系统的应用范围同时符合IEC60060-3的要求,本文结合磁矢位法(MVPM),精确计算并设计了适当的空心电抗器参数及结构。最后在实验室条件下对本系统进行相关测试,试验结果表明本系统可用于6/10kV电力电缆局部放电检测及定位。

This paper describes the design and development of a 20kV rated damped oscillating voltage （DOV） generator that can detect the partial discharge condition in 6/10kV power cables. A complete system using a novel high-voltage switch consisting of a series of connected insulated gate bipolar transistors （IGBTs） is designed and tested. The switch consists of 10 identical IGBT switch units, a multiple output isolated power supply system and a trigger unit. Physically, it is a 60cm diameter fan-shaped printed circuit board （PCB）. To coordinate the various tested objects and to comply with the IEC 60060-3 standards, an air-core inductor is calculated to precisely fit the most general application conditions using the magnetic vector potentials method （MVPM）. A laboratory prototype is assembled and tested. Waveforms illustrating the performance of the IGBT switch and the output of the DOV are presented. Finally, an application-oriented test demonstrates that the scheme can successfully complete the partial discharge （PD） test and PD location test for a cable sample.