Considerations for Inverter Topology Selection and Limitations in Active Power Filtering Applications

Abstract

This paper presents a modular inverter structure utilizing hybrid SiC MOSFET based active neutral point clamped inverter for active power filter (APF) applications. An FPGA-based digital controller is developed. One major factor in APF applications is the harmonic current capability of the system at higher order harmonics. Commercial products often have a derating curve for higher order harmonic ratings. This paper presents a case utilizing SiC MOSFETs to increase the switching frequency and reduce the LCL filter size. The presented approach is shown to extend the harmonic current capability up to twice in comparison with conventional IGBT-based systems.