Analytical Review on MLI based Active Power Filter to Reduce Harmonics for Improvement in Power Quality

Background: Poor power quality is serious problem in power system. The introduction of harmonics in power system makes its quality poor. This paper describes the analytical study of different topologies of Multi Level Inverter, switching techniques used for MLI, different Active Power Filters and their control strategies for compensating the harmonics. Method: Multi Level Inverter based shunt Active Power Filter has been used to reduce the amount of harmonics which enhances the power quality in distributed power system. Findings: Conventional inverters produce more harmonics in power system which can be reduced with the use of active power filters. Multi Level Inverter (MLI) in conjunction with Pulse Width Modulation reduces the harmonic contents and achieves sinusoidal signals without add-on circuitry. The output voltage provided by MLIs has small voltage steps, which results in good power quality and low harmonic components. The system is simulated using MATLAB/SIMULINK platform. Improvements: Line current distortion caused by the nonlinear loads and power electronic devices can be efficiently neutralized by shunt Active Power Filter both in transient and distortion voltage conditions.