A multilevel power conditioning system for superconductive magnetic energy storage

The introduction of multilevel converters makes possible the use of pulse width modulation (PWM) converters and fast switching medium power devices like insulated gate bipolar transistors (IGBTs) for high-voltage, high-power applications, such as flexible ac transmission systems (FACTS). This paper proposes a five-level voltage source inverter (VSI)-chopper for a superconductive magnetic energy storage (SMES) power conditioning system (PCS). The circuit topology and operation principles are presented. The advantages of the proposed power conditioning system have been investigated and compared with present PCS including a traditional transformer coupled multi-pulse VSI-chopper topology. The validity of the system is verified by computer simulation.