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 parameterization of gate units and the substantial device de-rating are substantial disadvantages of state of the art converters with parallel connected IGBTs. A new, low expensive and automated delay time compensation method without additional current measurements was introduced in [1]. 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 cosφ and m_a values as in a converter for drives.