Operation and Control of Converters Having Integrated Capacitor Blocked Transistor Cells

Abstract

Converters having Integrated Capacitor Blocked Transistor (ICBT) cells provide a new method to transfer high power in medium voltage or high voltage systems. One ICBT cell operates as a single switching device, series-connected ICBT cells operate as a single high-voltage device without suffering from large additional losses or the requirement of fast balancing controls. Converters with ICBT cells have the modularity and scalability like Modular Multilevel Converters but require much lower cell capacitances. The operation of converters with ICBT cells are analyzed. Different switching states and commutation sequences are presented. Based on the results, control methods are proposed to achieve desired converter outputs, low cell capacitor voltage ripples and cell capacitor voltage balance. The operation and control of converters having ICBT cells are demonstrated by simulation results in PLECS and LTspice.