Control of Hybrid Active Power Filter to Reduce Harmonics of 3-Phase Cap-Less Inverter

Abstract

Recently, material cost competitiveness in various fields, by applying a cap-less inverter technology that uses a small capacity film capacitor to the dc link, the harmonics of input current increase and the power factor decreases compared to the motor drive inverter that uses the existing large capacitor. The increase in harmonics must be installed by expanding the power facility capacity, and the installation of communication facilities sensitive to harmonics is limited. In addition, the decrease in power factor increases the reactive power component, which requires a large current compared to the actual operating capacity, and causes a problem of reducing the operating range of the product. The hybrid active power filter proposed in this paper reduces high order harmonics by applying L filter to the dc side of a 3 phase cap-less inverter for motor driving. The load harmonic compensation current for overall order harmonics through the active power filter. The input current harmonic is reduced by injecting with the current harmonic by inverting the phase. The IEC 61000-3-2 Class A of international harmonics regulations was met and verified using the proposed harmonic reduction system.