HIGH VOLTAGE SQUARE WAVE AND SPWM WAVE GENERATOR

摘要

A high voltage wave generator circuit is provided for generating high voltage square-waves and SPWM-waves. The circuit comprises a plurality of stages, each stage including (a) an input connected to a DC source, (b) a first switch, (c) a second switch, (d) an energy storage device and (e) a wave shaping resistor, wherein the first switch charges the energy storage device and the second switch discharges the energy storage device. Each of the stages is operable to generate waveforms and the stages are connected in cascade, and the stages are configured such that (i) the first switches and the second switches of the plurality of stages are operable to switch substantially at the same time, and (ii) when the first switches are "ON" the second switches are "OFF" and vice versa. The circuit is configured such that by charging the circuit and sequentially switching all of the first switches and then the second switches substantially at the same time, the stages are operable to cumulatively generate as an output high voltage square-waves and SPWM-waves. An insulation test apparatus based on the wave generator is also provided. Also, a novel method for testing rotating machine insulation is provided.