Current Harmonics Mitigation by Cascaded Multilevel Inverterbased SAPF during Unbalanced loading conditions

Abstract

Most of the non- linear loads in use today generate harmonics which have several detrimental effects on the power system. Shunt Active Power Filter(SAPF) is widely being employed due to its superior harmonic filtering capabilities. SAPF generates compensating currents that cancel or mitigate the harmonic currents produced by non- linear loads. In this research paper, a three-level Cascaded multilevel inverter based SAPF is presented and its performance is analyzed by using advanced Adaptive Neuro Fuzzy Inference System (ANFIS) controller. DC link capacitor voltages and percentage Total Harmonic Distortion (%THD) in source currents are measured at PCC for unbalanced loading conditions and results are presented.In this research, it is also proposed to employFive-Level and Seven-Level Cascaded Multilevel Inverters as VSI circuit for SAPF. Performance of these multilevel Shunt Active power filters is analyzed by ANFIS controller. Percentage Total Harmonic Distortion (%THD) in source currents measured at PCC and regulation of DC link voltage are observed. Instantaneous Active-Reactive power theory is implemented to compute reference compensating currents for all Shunt Active power filter models. Phase Disposition type Pulse Width modulation is chosen for generating gate pulses for VSI circuits of all Cascaded multilevel inverter configurations. Three-level, Five-level and Seven-level Shunt active power filter models are developed and simulated using MATLAB/ Simulink and results are compared.