DC link current in PWM inverters with unbalanced and nonlinear loads

A method is described for calculating the DC link currents of a three-phase inverter for unbalanced, balanced, linear and non-linear loads. The derived equations give the magnitude and phase of the mth DC link current harmonic in terms of the phase currents and the Fourier coefficients of the inverter phase voltage. The derived equations are validated using a 1 kW three-phase inverter with various balancedunbalanced linear and non-linear loads.