LCL Filter Design for Three Phase AC-DC Converters Considering Semiconductor Modules and Magnetics Components Performance

Abstract

LCL filters are commonly adopted to attenuate the current harmonics produced by Pulse Width Modulation (PWM) Voltage Source Converters (VSC). Due to the nature of LCL filters, several combinations of L and C can deliver the attenuation required by the standards. The optimal configuration is generally evaluated, considering power density, costs, and filter efficiency. This paper shows that semiconductor efficiency should also be considered as an important design variable. It is shown that the AC ripple across the converter side inductor can reduce, to a certain extent, the overall semiconductor losses, when commercial IGBTs and the respective anti-parallel diodes are used. Reduced losses have benefits in terms of semiconductor module lifetime, chip area and cost reduction, and simplification of cooling requirements. Higher AC ripple, however, negatively affect the filter losses. Nonetheless, inductive components are typically much less critical in terms of losses dissipation and lifetime than semiconductors.