Frequency domain analysis and evaluation of differential mode input current for three-phase DCM boost rectifiers with different control strategies

By using frequency domain analysis, it is possible to predict the low and high frequency harmonics of the differential mode input current of three-phase DCM boost rectifiers. This analysis is applied to three different modulation strategies, which are the constant duty-cycle control, the harmonic injection method and the variable switching frequency control. The results can be used to design the differential mode EMI input filter and to observe the PFC capabilities of DCM rectifiers. The theoretical approach is validated by time domain simulation and practical results.