Breadth-First Search Leakage Tolerant Commutation Method for Matrix Converters in Three-Phase Solid State Transformers

A leakage tolerant commutation method is proposed that enables the use of matrix converters in Solid State Transformers with three-phase high/medium frequency isolation transformers. Typical commutation methods for matrix converters such as two and four step commutation methods are not suitable in the presence of leakage inductances since they do not allow the recirculation of the leakage energy, this means that when using such methods it is necessary to use snubbers and clamping circuits to mitigate potential overvoltages on the transformer. The proposed commutation method does not require any additional circuitry and is suitable for multiphase converters. A systematic description of the process is provided along with simulation results that validate the proposed commutation method.