High-frequency leakage current that may cause serious conducted EMI problems flows through an inverter system. The paths of the leakage current are stray capacitors that are formed inside of motors, cables and IGBT modules.
This paper proposes a new IGBT module that realizes low conducted emission noise by flipping the IGBT chip of lower-voltage-side to decrease its stray capacitance. The leakage current flowing through the low-noise IGBT module becomes small, since the stray capacitor is a main path of the current. Through an experiment, it is clarified that the conducted emission level is reduced by 13dB at a maximum when the low-noise IGBT module is applied to a resonant-type inverter.