A novel single-switch resonant power converter for renewable energy generation applications

This paper develops a novel single-switch resonant power converter for renewable energy generation applications. This circuit topology integrates a novel single-switch resonant inverter with zero-voltage-switching (ZVS) with an energy-blocking diode with zero-current-switching (ZCS). The energy-blocking diode with a direct current (DC) output filter filters the output stage of the novel single-switch resonant inverter. Only one active power switch is used for power energy conversion to reduce the cost of active power switches and control circuits. The active power switch is controlled by pulse-width-modulation (PWM) at a fixed switching frequency and constant duty cycle. When the resonant converter is operated at discontinuous conduction mode (DCM), the inductor current through the resonant tank could achieve ZCS of the energy-blocking diode. Accordingly, a high energy conversion efficiency is ensured. Operating principles are derived and analyses are carried out based on the equivalent circuits for the proposed power converter under different operating modes. The operating principles of the converter were verified using a 32.4W, 70kHz experimental PV-powered load system. Given an appropriately chosen circuit parameters, the active power switch can be operated with zero-voltage switching and a measured energy conversion efficiency of the proposed topology of 97.3% can be achieved. Experimental results demonstrate a satisfactory performance of the proposed topology, which is especially suited to the energy conversion applications in renewable energy generation systems.