Adaptive Hysteresis Band Based Fuzzy Controlled Shunt Active Power Filter

Conventional hysteresis current controllers have the disadvantage of a variable switching frequency. This paper proposes a fuzzy hysteresis band technique for the current control for shunt active power filter (SAPF). An active harmonic filter is used to eliminate current harmonics caused by nonlinear loads. The current control strategy utilizes using a selective Filter STF method to improve power quality through compensating harmonics and reactive power required by a nonlinear load. The power quality standard IEEE-519 states that the total harmonic distortion (THD) caused by electrical equipment gear should be within the agreeable range of 5%. The simulation model of the overall system is developed in MATLAB/Simulink environment. This strategy makes algorithm independent of load parameters. From analysis, it has been found that fuzzy hysteresis band technique proves to be effective in reducing the THD of the source current.