A Novel Soft Switched Cycloinverter

A novel soft switched insulated-gate bipolar transistor (IGBT)-based cycloinverter, which is capable of converting voltage at the main frequency to voltage at high frequency, is proposed to improve the previously proposed pulse width modulation cycloinverter. An auxiliary switch, along with an inductor, is used to have simultaneous zero-current switching and zero-voltage switching for turn-on transitions of the IGBT in order to mitigate the internal losses and total harmonic distortion factor in the inverter. The principle of operation and design consideration are presented. The proposed cycloinverter is compared with a conventional hard switched cycloinverter, and it has been demonstrated that the losses have been reduced approximately 50% by this new switching technique and the efficiency of the inverter is increased significantly. A prototype of the cycloinverter is developed in the laboratory for verification of the simulation results. Experimental results are found in good agreement to the simulated results.