Abstract—Hysteresis current control is one of the simplest techniques used to control the magnitude and phase angle of three phase shunt active filter injection currents for high speed compensation systems, primarily because of its simplicity of implementation, fast current control response, and inherent peak current limiting capability. However conventional fixed-hysteresis band control has a variable switching frequency throughout the fundamental period, and consequently the load current harmonic ripple is not optimum. Among the various adaptive hysteresis band techniques, analytical method is a regular and simple for solving misrules of fixed hysteresis band. But it requires good knowledge of the load parameters. This paper describes the application of fuzzy logic theory to the three-phase shunt active power filter for the power-quality improvement and reactive power compensation required by a nonlinear load under constant switching frequency. The advantage of fuzzy logic control is that it does not require a mathematical model of the system. Fuzzy hysteresis band techniques are employed to derive the switching signals. The novel adaptive hysteresis band current controller changes the hysteresis bandwidth according to modulation frequency, supply voltage, DC capacitor voltage and slope of the reference compensator current wave. Simulation results, obtaining using Matlab/Simulink, show the effectiveness of fuzzy logic controllers in optimizing the PWM technique of the active filter with constant switching frequency.

Index Terms—active power filter, fuzzy logic theory, constant switching frequency, harmonic compensation.

M.B.B. Sharifian is with the Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz, Iran. (Phone: +98 411 3294120).
Reza Rahnavard is with Azerbyjan Regional Electric Company, Tabriz, Iran.
Yousef Ebrahimi is with Tabriz Gas Station, National Iranian Gas Company, Tabriz, Iran.

Cite: M.B.B. Sharifian, R. Rahnavard, and Y. Ebrahimi, "Variable Hysteresis Band Current Controller of Shunt Active Filter Based Fuzzy logic Theory under Constant Switching Frequency," International Journal of Computer and Electrical Engineering vol. 1, no. 2, pp. 236-244, 2009.