Three-phase 200 kVA UPS with IGBT consisting of high power factor converter and instantaneous waveform controlled HF PWM inverter

A description is given of a three-phase 200 kVA UPS (uninterruptible power supply). In this UPS, both the input converter section and the output inverter section utilize an IGBT (insulated gate bipolar transistor) as a main semiconductor switching device. Compared with the conventional type of UPS using bipolar junction transistors, this UPS provides an equivalent efficiency in spite of having an approximately 10 times higher switching frequency. As a result, the new UPS is of a compact, lightweight, low-acoustic noise, and high performance design, resulting in reduced input harmonic current (less than 5% THD) and also a reduced output voltage distortion (less than 8% THD) under a nonlinear load.<<ETX>>