No abstract

This paper presents the analysis and the comparison study of a High-voltage High-frequency Ozone Generator using PWM and Phase-Shifted PWM full-bridge inverter as a power supply. The circuits operations of the inverters are fully described. In order to ensure that zero voltage switching (ZVS) mode always operated over a certain range of a frequency variation, a series-compensated resonant inductor is included. The comparison study are ozone quantity and output voltage that supplied by the PWM and Phase-Shifted PWM full-bridge inverter. The ozone generator fed by Phase-Shifted PWM fullbridge inverter, is capability of varying ozone gas production quantity by varying the frequency and phase shift angle of the converter whilst the applied voltage to the electrode is kept constant. However, the ozone generator fed by PWM full-bridge inverter, is capability of varying ozone gas production quantity by varying the frequency of the converter whilst the applied voltage to the electrode is decreased. As a consequence, the absolute ozone quantity affected by the frequency is possibly achieved.

Three-phase PWM AC-AC Matrix Converter using 9-sets of IGBT-Power Diode bi-directional switches as main power switching devices, given output voltages of 3, 6, and 9-pulses per half cycle, is synthesized to determine the required PWM switching waveforms for three-phase matrix converter circuit as well as the required PWM switching waveforms for the multiplexer/de-multiplexer circuit. Theses switching waveforms are used to design and construct the various pulses Three-Phase PWM AC-AC Matrix Converter. This converter can be divided by 6-modes and described in this paper. The converter is tested with passive load as well as induction motor load to measure output voltage and current waveforms at different frequencies of each modulation index. Experimental ratios of RMS output voltage and frequencies as modulation index varies for the case of passive load and induction motor load are plotted and compared with theoretical results. Both of them show to agree, and appear to be constant ratio (V/f constant) which is useful for speed control of an induction motor.