Design a single-phase active power filter using indirect control scheme for photovoltaic system

During recent years due to the policy making at the international level as well as the policies adopted by the Ministry of Energy of Iran at the domestic level, the use of small photovoltaic generators has received priority by the household subscriber. Because such generators shown on-linear behavior resulting from uncertainty of the sunlight radiation, designing and employing active filters for them seems necessary. Accordingly, a single-phase parallel active filter has been designed for compensating the current and voltage harmonics of a photo voltaic system. The filter has been engineered through in direct method and for the adjustment of reference flow amplitude-that regulates the DC capacitor´s voltage-a PI controller has been used. Also for controlling the output current of the parallel active filter with the lowest ripple, the hysteresis band current controller has been employed. In order to obtain a sinusoidal wave with reasonable THD, a passive low-pass filter has been used. Finally, the effects of the explained control pattern for the single-phase active filter and the photo voltaic system have been simulated using Matlab/Simulink software. Results from the simulation show that both voltage and current harmonics´ values have considerably been improved and in some cases have been decreased about 80 percent.