Parallel connection of multiple resonant inverters to drive high-power high-intensity discharge lamps

This paper presents the analysis and design of a new configuration of a resonant inverter suitable for high-intensity discharge (HID) lamp ballast applications. The proposed inverter results from the parallel connection of three class D LC_P resonant inverters, sharing the total load current. In this way, a reduction of the conduction losses is achieved. The regulation is implemented at constant frequency, modifying the phase displacement of the drive signals of one inverter section with respect to the others. High efficiency dimming operation at around 50% of full power is achieved canceling one of the non-controlled phases