Experimental considerations on adjustable dead-time controlled three-phase resonant snubber inverter

Resonant snubber inverter (RSI) uses lossless snubber commutation, which can achieve zero voltage switching (ZVS) turn-on in main switches without using auxiliary circuit, in order to gain high efficiency. However, in these schemes, ZVS turn-on in main switches without using auxiliary circuit fails near zero output current range. As a solution of this problem, adjustable dead-time control, which can avoid the failure of ZVS turn-on in main switches near zero output current range, has been proposed. In previous work, adjustable dead-time control has not been applied to three-phase RSI. Thus, in this paper, adjustable dead-time control was applied to three-phase RSI. In addition, the effectiveness of adjustable dead-time control is shown by comparing between the adjustable and the fixed dead-time control in simulations using PSIM and in experiments. As a result of simulations and experiments, it was verified that adjustable dead-time control scheme could apply to three-phase RSI. In addition, ZVS turn-on in the main switches achieved at near zero output current condition by use of the scheme. Efficiency on adjustable dead-time is higher than that on fixed dead-time in low output power.