Abstract: It is composed of a three-phase three-level inverter 1, three single-phase five-level inverters 2, each of which is connected in series with an output of each phase of the three-phase three-level inverter 1, and pulse width modulation control means 8 provided for each phase which supplies gate pulses to the three-level inverter 1 and the single-phase five-level inverter 2 of the relevant phase.

Abstract: A compact, inexpensive, large-capacity ozone generator with increased ease of apparatus maintenance. An ozone power supply includes an n-phase inverter for obtaining an AC voltage having a predetermined frequency and outputting an n-phase AC voltage waveform; n reactors and an n-phase transformer for converting an n-phase AC voltage to a high AC voltage; n high-voltage terminals for outputting the n-phase high AC voltage; and a low-voltage terminal having a common potential. Ozone generator units are electrically divided into n pieces within a discharge chamber. Each ozone generator unit includes n high-voltage electrode terminals and one low-voltage electrode terminal, common to all ozone generator units. Each ozone generator unit supports an n-phase AC discharge to generate ozone.