Surge voltage suppression methods for three-phase to single-phase matrix converter

This paper discusses surge voltage suppression methods in order to design a large capacity three-phase to single-phase matrix converter which is used in AC-DC converters. In order to reduce the surge voltage, the design criteria based on the flow chart of a laminated bus bar (LBB) for the three-phase to single-phase matrix converter is clarified to achieve the lowest stray inductance. As a result, the maximum stray inductance of the LBB for 200-V, 50-kW is achieved to 59 nH in simulation and 58.3 nH in experiment. Besides, when the surge voltage exceeds the tolerance, a snubber capacitor is used in order to limit the surge voltage. In this paper, the design method of the snubber capacitor is also proposed. Concretely, the relationship among snubber capacitance, surge voltage and turn-on loss is derived. As the result, it is confirmed that the surge voltage becomes 231 V when the output current is 310 A by experiment. Thus, the design method of snubber capacitor to suppress the surge voltage is validated.