Normalized Sigmoid Function LMS Adaptive Filter based Shunt Hybrid Active Power Filter for Power Quality Improvement

This paper presents a normalized sigmoid function least mean square (NSF-LMS) based adaptive filtering method for shunt hybrid active power filter (SHAPF) for enhancement of power quality at the distribution level. The proposed adaptive filter is designed for the reference current generation and mitigation of current harmonics in the source, and for reducing the %THD to the IEEE-519 standard value. The performance of the SHAPF system with proposed NSF-LMS method is analyzed for steady-state as well as transient conditions. The passive power filter (PPF) is designed for 5th and 7th harmonic order. The simulations are performed using MATLAB/Simulink software, and the results are analyzed. The OPAL-RT digital simulator was used to run the simulations in real time, and the results were reported.