Dead-time compensation scheme for adjustable dead-time controlled resonant snubber inverter

Abstract

Auxiliary resonant snubber inverters (RSIs) have been proposed a solution of demands for inverter, which are high efficiency and low EMI. In RSI, zero voltage switching (ZVS) on the inverter main switches is achieved by use of the auxiliary circuit; however, additional conduction loss increases simultaneously. The operating frequency of the auxiliary circuit in RSI can be reduced to a half of switching transition of a main switch when natural ZVS, in which ZVS can be achieved without using auxiliary circuit by using output current, is used. As a result, additional conduction loss can be suppressed. However, in this scheme, ZVS turn-on on main switch is failed near zero output current when dead-time was constant. As a solution for this problem, adjustable dead-time control scheme for RSI has been proposed; however, output current is distorted in low output power range. Thus, this paper proposes a dead-time compensation scheme for adjustable dead-time control. This paper shows the basic concept of the proposed compensation scheme. In addition, the effectiveness of the proposed scheme was verified through simulations using PSIM and experiments. As a result, it was verified that the proposed control scheme was able to improve THD without decreasing in efficiency.