Improved high voltage pulse generator for automated insulator fault detection

Abstract

Insulators that have suffered invisible damage can cause catastrophic system failure. Detection of the fault through visual inspection is not possible. An automated non-destructive test method is preferred. We have developed a system capable of peak pulse voltage of > 50 kV with fast rise time and limited pulse energy coupled with a high speed FPGA processor to analyze the output voltage and current for potential insulator faults. This paper will discuss the design and test results of a high-voltage pulse generator with automated fault detection. This pulse generator has been improved using a new high-voltage solid state switch based on thyristors capable of >100 A/ns and >300 V/ns. Using this switch increased the efficiency by 25% versus an IGBT based switch. This paper will also discuss the design and test results of this new switch.