Role of PI/Fuzzy Logic Controlled Transformerless Shunt Hybrid Power Filter using 6-Switch 2-Leg Inverter to Ease Harmonics in Distribution System

Background/Objective: The intention of this paper is to propose a Transformerless Shunt Hybrid Power Filter (TSHPF) using 6-Switch 2-Leg Inverter (SSTL) to enhance the power quality in distribution systems. Methods/Statistical Analysis: The TSHPF comprises of SSTL inverter and passive filter coupled to Point of Common Coupling (PCC). Here SSTL inverter acts as Shunt Active Filter (SAF). The DC bus voltage in SSTL inverter is retained by using PI/Fuzzy controller. To generate switching pulses in inverter linear control method is used. Here a TSHPF incorporated with fuzzy controller is developed and comparative analysis is made w.r.t conventional PI controller. Findings: The proposed system is simulated in MATLAB/ SIMULINK for both control strategies. Simulation results shows that compared to PI, by including fuzzy controller the total harmonic distortion is reduced from 8.64% to 3.40%. Improvement: The PI controller is not feasible because explicit mathematical model is needed. Hence, fuzzy controller based TSHPF is much efficient for enhancing the power quality.