Voltage ripple analysis based on DC-link current harmonics for Voltage Source Inverters

The voltage ripple is the predominant dc-link capacitor design parameter in automotive traction voltage source inverters. Therefore, the reduction of the voltage ripple results in the decrease of the dc-link capacitance. In this research, the voltage ripple dependencies are analyzed for the space vector and the discontinuous space vector modulation, which lays a foundation in reducing the capacitance size based on new control methods. Hence, the dc-link current harmonics are analyzed for different sets of operating points and their effects on the voltage ripple are explained. Furthermore, the similarity of the dc-link rms current for these two modulation schemes is described.