Type-2 Fuzzy Logic Controlled Three-level Shunt Active Power Filter for Power Quality Improvement

This article proposes a three-level shunt active power filter for power quality improvement using a type-2 fuzzy logic controller (T2FLC). The reference compensating current is extracted using the P-Q theory. The majority of works previously reported are based on two-level inverters with a conventional Proportional integral (PI) controller, which requires rigorous mathematical modeling of the system. In this paper, a T2FLC controlled three-level active power filter is proposed to overcome the problem associated with PI controller. The T2FLC algorithm is applied for controlling the DC-side capacitor voltage as well as the harmonic currents of the three-level active power filter. The active power filter with a T2FLC is simulated in MATLAB Simulink environment (The Math Works, Natick, Massachusetts, USA). The simulated response shows that the proposed shunt active power filter controller has produced a sinusoidal supply current with low harmonic distortion and in phase with the source voltage. To verify the simulated response, a prototype model of inverter has been developed, and the control pulses for the active power filter are generated using a dSPACE1104 (dSPACE GmbH, Paderborn, Germany) controller. The experimental results demonstrate that the T2FLC greatly improves the transient performance of the three-level active power filter.