Sinusoidal Current Operation of Delay-Time Compensation for Parallel-Connected IGBTs

The parallel connection of IGBTs is being applied in various low-and medium-voltage converters. The selection of the devices, the manual parametrization of gate units, and the substantial device derating are substantial disadvantages of state-of-the-art converters with parallel-connected insulated-gate bipolar transistors (IGBTs). A new, low-expensive, and automated delay-time compensation method without additional current measurements was introduced in the 2011 IEEE Energy Conversion Congress and Exposition. This paper briefly reviews the structure and function of this new scheme, shows the extension of the scheme for three parallel-connected IGBTs, and investigates the performance of the new delay-time compensation principle for sinusoidal current operation at different cos phi and m(a) values, as in a converter for drives.