Research of the dead-time compensation based on the three-phase grid-connected inverter

Abstract

Time delay must be inserted in the switching signals to prevent the simultaneous conduction of two switching devices in the same leg of the inverter, however, this results in a decrease of the fundamental component and an increase of the odd-order except the triple-n harmonics of the output voltage of the inverter. The distortion of output voltage further distorts the output current in turn. This paper analyses the dead-time effect in detail under Space Vector Pulse Width Modulation (SVPWM), and presents a general computation method of the harmonics of the error voltage. On this basis, a dead-time compensation scheme is proposed. MATLAB simulations and experiments are carried out based on the three-phase grid-connected inverter. The results well demonstrate the effectiveness of the proposed strategy and proved that this system has the advantage of high power factor in the AC side and little harmonics pollution to the grid.