Fuzzy logic controller for three-level shunt active filter compensating harmonics and reactive power

In this paper, the three-level inverter is used as a shunt active power filter, making use of the multi-level inverter advantages of low harmonic distortion, and reduced switching losses. This PWM inverter is employed as shunt APF compensating reactive power and suppresses harmonics drawn from a nonlinear load. Most previously reported three-phase active power filters are based on two-level inverters with conventional controllers requiring a complex and a complicated mathematical model. In order to overcome this problem a fuzzy logic controller applied and extended to a three level shunt APF is proposed. In this paper, fuzzy logic control algorithm is proposed for harmonic current and inverter dc voltage control to improve the performances of the three levels active power filters. The MATLAB Fuzzy Logic Toolbox is used for implementing the fuzzy logic control algorithm. The obtained results showed that, the proposed shunt active power filter controller have produced a sinusoidal supply current with low harmonic distortion and in phase with the line voltage. (C) 2009 Elsevier B.V. All rights reserved.