Design aspects of paralleled three-phase DCM boost rectifiers

The interleaved operation of paralleled boost rectifiers reduces the amplitude of the input current ripple and increases its effective frequency. As a consequence, the size and volume of the input EMI filter can be reduced. This work provides a detailed analysis of the fundamental component of the input current ripple of the interleaved system along with curves that facilitate the input EMI filter design. It also presents an equivalent circuit model that is valid at low frequency and can be used to design the voltage loop control. The experimental results are provided for a prototype rated at 220 V input phase voltage, 8 kW, 40 kHz, and 800 V output voltage. The harmonic distortion of the paralleled system complies with IEC 61000-3-2 Class A standard.