Study Of Advanced Control Algorithm And Its Application In Active Power Filter

The extensive use of power electronic equipment makes harmonic pollution is becoming increasingly serious, harmonic content of the electric network is increasing, resulting in the deterioration of power quality. Active Power Filter (APF) can track and compensate the harmonics of the changing frequency and amplitude, and compensation characteristics is not influenced by electric network impedance, possessing good filtering properties, which plays an important role in governance of the harmonic pollution in the electric network.This paper takes the three-phase shunt active power filter as the research object, firstly traditional detecting method for harmonic current based on theory of instantaneous reactive power, theoretical analysis and simulations is presented. Because instantaneous reactive measures have some advantages, this paper present theoretical analysis of detecting method based on Madaline and FFT. On the base of this, simulation research for these two methods is presented. The simulation results show that these two methods have very good real time characteristic and better measurement accuracy. Detection algorithm is simple and easy to adjust and achieve.Since APF is a non-linear and intensive coupling system, and hard to build a mathematical model precisely, it makes big potential for the advanced control technology applications. This paper design High Order Differentiator Feedback Controller (HODFC), Fuzzy Neural Network Controller (FNNC) and Sliding Mode Variable Structure Controller (SMVSC) based on advanced control strategy, and applied these three controllers to DC voltage control system of APF respectively. The simulation results show that excellent control effects of both harmonic current suppression and maintain DC voltage stability compared to traditional PI control measures, with the feasibility and effectiveness on APF control. Hence, applying the advanced control technology to APF benefits the APF compensation performance.TMS320LF2407 of DSP chip as a control core, this paper introduces the design solution of APF digital control system, and design hardware circuits and software control process of the whole control system.