Digital Current Controller with Fixed Switching Frequency based on Controlled-type Soft-switching Inverter

Variable switching frequency is an unsolved problem in controlled-type soft-switching inverter. This paper presents two controlled-type soft-switching current modulations capable to achieve fixed switching frequency, one is by the combination of hysteresis control and triangular carrier control, the other is by variable hysteresis bandwidth. Meanwhile, a prototype of a single-phase full-bridge inverter and its digital control method have been designed and tested under the two fixed switching frequency modulations. Experimental results are given to demonstrate the validity and feasibility.