In order to improve performance of the inverter

a single-phase full bridge energy-saving inverter with auxiliary circuits in parallel with main switches is proposed.Limited monopole SPWM(Sinusoidal Pulse Width Modulation) is applied in the inverter.Only one main switch and one auxiliary switch need be controlled in every switching period.The duty cycle of the auxiliary switch is constant.Setting threshold of resonant current need not be designed to control the auxiliary switch.During the process of commutation in every switching period

the voltage across the resonant capacitor in parallel with the main switch decreases to zero and zero-voltage turning-on of the main switch can be achieved.All the components in the auxiliary circuit are not in series with DC(Direct current) bus

which can effectively reduce the conduction loss of auxiliary circuit.The working principle is analyzed in detail

and the experimental results show that the main switch and auxiliary switch can realize soft-switching.Therefore

the topology can effectively reduce the switching losses and improve efficiency of the inverter.