1-phase Active Power Filter with modified sigma-delta modulator in control section

Abstract

The work presents conception of 1-phase shunt Active Power Filter (APF) based on the modified sigma-delta modulator (SDM). The modification depends on including in SDM the dynamic hysteresis comparator. Thank to this feature the resolution of SDM output bit stream is, theoretically, unlimited. As result it is possible to precise mapping of the APF input (power grid) current in the reference signal. Due to very high switching frequency of the power devices, in the output stage of APF the GaN E-HEMTs are included. In the work: APF basics, results of simulation tests, and possible practical arrangement of APF are presented.