Design of a three-phase 70 kW Current Source Inverter for Photovoltaic Applications Using a New 1.7 kV Full-SiC Voltage Bidirectional Power Module

Nowadays, the availability of high-voltage Silicon Carbide (SiC) devices makes possible to redesign the classical multi-stage DC-AC photovoltaic (PV) converters in order to reduce inverter complexity and costs, while improving reliability. Having this in mind, the Current Source Inverter (CSI) is proposed. In this paper, the operation of a new 1.7 kV full-SiC voltage bidirectional power module suitable for PV CSI applications is discussed. From experimental switching characterization results, the tradeoff between switching losses and EMI behavior is analyzed. Then, based on the estimation of semiconductor efficiency and thermal limits, the main design guidelines for a 70kW (60kHz) CSI are given. Furthermore, the inverter operation is discussed under two different grid voltage levels (690 Vac and 800 Vac).