Conducted emissions simulation technology for an inverter device integrated into the motor

In recent years, it has become essential to use simulation to design noise filters because the development of fast-switching devices has increased the noise in power electronics products. This paper proposes a simulation method for conducted emissions in inverter devices that does not require a highly accurate SPICE model of the switching devices. This paper focuses on an inverter device integrated into the motor that uses the grounding of the motor housing as the negative current path without the negative wiring harness between the inverter device and power supply. It is considered that only the differential mode noise contributes to the line impedance stabilization network (LISN) noise terminal voltage, because the noise propagated through the parasitic capacitance of the motor returns to the inverter through the ground plane. Each component in the test layout for the conducted emissions is modeled by actual measurement or electromagnetic field analysis and each equivalent circuit is integrated in LTspice, which makes the integration process simple or similar. The simulations results show that the LISN noise terminal voltage can be predicted with a measurement error of ± 6 dB in the 100kHz to 30MHz band.