An 81 Level Inverter with Low Device Switching Frequency Operation

Abstract

This paper implements and analyses the effectiveness of a cascaded H bridge 81level inverter topology for low device switching frequency (LDSF). The conventional asymmetrical cascaded multilevel inverter topology used to evaluate the proposed fundamental frequency switching technique, which requires the minimum number of DC sources, power semiconductor switching devices and corresponding gate driver circuits as compared to other multilevel inverter topologies. The proposed technique applicable to other emerging multilevel inverter topologies also. High-frequency operation of power semiconductor switching deviceincreases the device temperature and limits the device switching frequencyin high power applications. So there is a need for compromise between device switching frequency and quality of converter output current is compromised based on the thermal constraints. In multilevel inverter topologies, no compromise required for seven or higher levels with the rated fundamental frequency. The proposed topology with the fundamental switching technique has been verified using a computer simulation program and the results are experimentally executed with prototype models.