Replacing silicon IGBTs with SiC IGBTs in medium voltage wind energy conversion systems

This paper proposes replacement of silicon (Si) IGBT based multilevel inverters and interleaved boost converters with simpler power electronic topologies, using silicon carbide (SiC) power semiconductor devices, in medium voltage wind energy conversion system (WECS). For medium voltage WECS of 3-6kV and 2-5MW multilevel inverters and interleaved boost converter topologies are used. Simpler topologies like two level inverters and boost converters cannot be used. The main reason being non-availability of silicon IGBTs for higher blocking voltages at required current and switching frequency. In recent years SiC power devices have been developed which can block several kilovolts, conduct high currents at high switching frequencies. But the main challenge in their use is high cost. This paper proposes for medium voltage, SiC based WECS can be made cost comparable with existing silicon IGBT based systems by using simpler power electronic topologies. In this paper a detailed comparison is presented between SiC based boost converter and two level voltage source inverter, respectively with Si based interleaved boost converter and multilevel inverter. All four systems are simulated in SIMULINK environment for 3 KV, 2.15 MW WECS. Simulations results are presented and calculations are discussed.