Voltage-based harmonic compensation using MCCF state estimation

Abstract

The majority of modern loads are based on power electronic devices, resulting in harmonic current emission. In consequence, increasing harmonic voltage levels are observed in distribution grids. Shunt active power filters (SAPF) can decrease the harmonic voltage distortion with a voltage-based harmonic compensation scheme. This paper presents a method for voltage-based selective harmonic compensation (SHC). Multiple complex coefficient filter (MCCF) state estimation is utilized for harmonic extraction. Stationary frame generalized integrators (SGI) provide control of the selected harmonic compensation. As the voltage-based SHC is implemented in stationary reference frame, computational efforts are reduced compared to synchronous reference framed SHC methods. In addition, the MCCF state estimator determines grid fundamental for robust grid synchronization in presence of imbalance and harmonic voltages, further decreasing computation requirements in the overall SAPF control. Simulation results validate the effectiveness of the proposed method.