The invention provides a novel resonant DC-link
soft switching inverter and a modulation method thereof, and relates to the technical field of inverters. The
inverter comprises an auxiliary resonant circuit, an
inverter bridge, a
load circuit and a DC power supply, wherein the auxiliary resonant circuit comprises a
bus switch tube, two auxiliary switch tubes, two auxiliary resonant inductors, a primary
resonant capacitor, two auxiliary resonant capacitors, an anti-parallel
diode of the
bus switch tube and four auxiliary diodes; the inverter bridge is of a three-phase bridge structure; the
load circuit is a three-phase
resistor-
inductance load; and various main power switch tubes of the inverter bridge work in manners of sine
pulse width modulation and complementary turn-on at a
phase difference of 180 degrees. According to the novel resonant DC-link
soft switching inverter, a zero-crossing reverse process of current of each auxiliary resonant
inductor is avoided, the service life of the inverter is prolonged, and the current stress of the auxiliary switch tubes of the inverter, the
conduction loss of the auxiliary resonant circuit and the switching losses of the
bus switch tube and the auxiliary switch tubes are effectively reduced.