Research and implementation of harmonic detection and current compensation technology in active power filter

In recent years, with the wide application of modern power electronic equipments, harmonic pollution in electrical power system becomes more and more serious. As the primary means of harmonic suppression, active power filter(APF) has been drawing more and more attention. The working principle of APF is described in detail in this paper. And then a new control strategy is proposed to detect the harmonic current accurately and obtain good performance of current tracking, In this strategy, the fast fourier transform algorithm(FFT) method is used to detected the harmonic current, and the space vector pulse width modulation(SVPWM) current control method based on indeterminate frequency hysteresis is used to track the compensating current. The results of simulation and experiment have shown that it can greatly reduce the distortion rate of the grid current and restrain harmonic pollution of the grid.