Fundamentals of a new family of auxiliary resonant snubber inverters

Several auxiliary commutated soft-switching inverters proposed in the past can be grouped into a new family of auxiliary commutated RSIs (resonant snubber inverters). The purpose of this paper is to explore the fundamentals for the whole family of the auxiliary commutated RSIs. With topological study and experimental data, the paper describes (1) basic principle of auxiliary resonant circuit operation that affects the device switching and (2) features of different auxiliary resonant commutation techniques. The paper also proposes (1) resonant circuit design criteria based on dv/dt and di/dt limits and (2) variable timing control adaptive to load current to improve the inverter efficiency. Experimental results are provided to verify the concept of zero crossing control, dv/dt and turn-off energy reduction, and efficiency improvement with the variable timing control technique.