Silicon Carbide Based Three Phase Inverter With Higher;Efficiency, Power Capability and Power Density ForRenewable Energy Applications

Abstract

In this Project 3 Phase 4-Wire 2-Level neutral point clamped SiC MOSFET based Voltage Source Inverter (VSI) was carried out. VSI was operated at 30 kHz switching frequency using neutral air cooling Aluminium (Al) heat sink. While designed VSI makes 3 phase connection possible, mid-point of the capacitors allows fourth wire connection as a neutral point. Properly designed, the LCL supply filter is used instead of L and LC type filters in this work since it provides a much better suppression at the modulation frequency. As a switching method Sinusoidal Pulse Width Modulation (SPWM) method was preferred and open loop control strategy was applied. Thanks to the SiC based switching device, high switching frequency operation was realized with very low losses and also filter size was reduced dramatically because of high switching frequency. Grid connection and renewable energy source compatibility took into consideration when electrical parameters were chosen. Proper gate driver design was also cared and suitable gate driver was designed. High power density was obtained at low volume and mass. Approximately 2.35 kW power was produced in unit volume (decimetre cube) and more than %98.5 efficiency was obtained.