A soft-switching full-bridge inverter with high efficiency

Abstract

A Zero-Voltage-Switching (ZVS) PWM scheme for full-bridge inverter with active-clamping technique is proposed. The ZVS condition is analyzed and the ZVS PWM scheme is designed to realize zero voltage switching for both main switches and auxiliary switch in a large power range. The ZVS PWM scheme also adjusts the energy stored in resonant inductor with variation of load to reduce the circulating loss in light load range. The switching frequency is increased and the filter inductor is significantly reduced. The experiment on a 3kW prototype shows the realization of ZVS and high efficiency. Index terms-Zero voltage switching, full-bridge inverter, ZVS PWM

SiC full-bridge grid-tied inverter with ZVS-switching

“…6. This modulation scheme of full-bridge is similar to the FDM scheme at most of the time in a full cycle T s , except an interval of commutation from body diode to MOSFET [18].…”

“…The switching loss is lowered as the ZVS is achieved with a DPM scheme. ZVS PWM schemes based on the actively clamped inverter are introduced in [15][16][17][18]. In literature [19], ZVS performance of 1200V SiC MOSFET is evaluated with respect to 1200V Si IGBTs and 900V SJ-MOSFET.…”

Leakage current suppression for transformerless ZVS full-bridge inverter

“…1 and the parameters are shown in Table 1. Zero voltage switching is archived by the auxiliary resonant branch and the ZVS SPWM [7]. Comparing with the hard-switching PV inverters, the ZVS full-bridge inverter has higher efficiency and the switching frequency is increased to 100kHz.…”

“…V pv is the voltage of PV panels and V Cc is the voltage of the clamping capacitor in Fig. 1, which is approximate 40V in steady state [7]. Another three PWM voltage sources represent the drain-source voltage of main switches (S 1 , S 2 ) and the auxiliary switch S a .…”

“…In order to obtain higher efficiency and power density, soft-switching technique with higher switching frequency has potential in transformerless PV application. With the ZVS sinusoidal pulse width modulation (SPWM) proposed in [7], zero voltage switching is realized in a 3kW full-bridge inverter and the highest efficiency is 98.7%. The switching frequency is increased to 100kHz and the size of the inductor is reduced, which makes it high efficiency solution for PV inverter.…”