Closed-loop regulated power supply for ozone generation based on buck converter and current-fed push-pull resonant inverter

In this paper the design, implementation and experimental results of a high-voltage power supply for ozone generation are presented. The power stage is formed by a buck converter plus a current-fed parallel-resonant push-pull inverter. The buck converter is used to both regulate the output power against the line voltage variation, and to control the power delivered to the ozone generator (OG). The push-pull inverter assures safe operation of the OG by working at the parallel resonant frequency given by the high-voltage transformer plus OG characteristic. In this paper, the closed-loop operation of the proposed converter is analyzed and implemented as a method to compensate variations in the line voltage and in the OG. A low cost commercial UC3872 integrated circuit is used to control both the push-pull inverter and the buck converter, providing OG power control and regulation via buck converter duty cycle. Protections against short circuit and no load operation are also implemented. Experimental results for a 100 W prototype are shown and discussed.