Sensorless adaptive control of resonant snubber inverter for photovoltaic applications

This paper proposes a new adaptive control technique of the auxiliary branch of the resonant snubber inverter for photovoltaic (PV) applications. By varying the turn-on time of the auxiliary branch based on the load current, the auxiliary resonant current is reduced without the need for any additional components, decreasing the circulating losses and improving system efficiency. An analysis of the resonant snubber inverter operation is discussed. Different control strategies of the auxiliary branch are compared. A 600 W prototype is built to verify operation of the adaptive control technique and to measure the performance improvements. The measured peak and weighted California Energy Commission (CEC) efficiencies are 98.16% and 97.56%, respectively.