Harmonic modeling of a vehicle traction circuit towards the DC bus

Different converters such as the traction inverter and DC/DC converter are connected to the dc bus of an electric or hybrid electric vehicle. Harmonic models of these devices towards the dc bus are needed to investigate different phenomena like the dc bus transients and ripples. A high-frequency harmonic model of a traction circuit, a drive system based on a three-phase inverter connected to an ac motor, is presented and explained. The model is extracted from an analytical approach developed for a three-phase inverter with a sinusoidal PWM controller. In addition to the analytical formulation, simulations and experimental results of a plug-in vehicle are provided to verify the spectrum of the dc bus waveforms.