Study On Harmonic Current Prediction Algorithm And Technique Of Shunt Active Power Filter

A lot of power electronic equipment and nonlinear loads have been widely applied to each industry of the production and life. At this point, the power system harmonic pollution is increasingly serious. For high power quality requirements, the study of harmonic suppression has a great theoretical and practical significance.Active power filter (APF) is the most effective means of power harmonic suppression which has a better dynamic performance, more compensation functions and doesn’t resonate with the power system compared with passive power filter. At present, the study of APF topology, harmonic current detection and compensation current control method is the main direction of APF research.The object of this study is a three-phase three-wire shunt active power filter. Based on the system structure features, obtain electrical mode of APF. Analyze the main factors which affect the APF system performance. Subsequently set up APF mathematical mode to establish the mathematical relationship of the system parameters. Calculate the range of capacitance and inductance parameters in the main circuit.Harmonic suppression has a high requirement on APF system real time, but the system generates inevitable delay in the harmonic digital harmonic detection and control. System delay would have serious influence on the APF compensation performance. The most effective measure to reduce the system delay influence is the harmonic current prediction algorithms in signal processing. According to the three-phase instantaneous reactive power theory, this paper proposes a harmonic current prediction algorithm for APF. Design every aspect the algorithm step by step based on the whole idea. Then, build the Simulink mode of APF on the MATLAB software platform. Simulation results show that harmonic current prediction algorithm could speed up the system response and reduce the delay impact on system.Finally, on the basis of APF mathematical mode and simulation mode set up APF experimental prototype. Analyze and design APF system hardware platform and software programming to achieve harmonic current prediction technique. Experimental results show that harmonic current prediction technique could reduce the harmonic distortion and improve the system dynamic compensation ability.