The Research On Parallel Three-Phase Four-Wire Active Power Filter

With the improvement of China’s economic strength and rapid industrial processes, thehigh-power electronic devices are widely used in the industry gradually, and as a result theharmonic pollution has become a serious problem. The harmonic control problem quicklybecome a focus topic，therefore the harmonic has become a key factor in the power system.The economic technology is developing at a high rapid, at the same time, the reactive currentand the harmonic current injecting the power system can not be ignored due to the high-powerelectronic devices.Base on this situation, this paper will research power quality problem, study in depth,simulate and do some experiment. It will dig out huge market application potential to realizeharmonic control by introducing the active power filter in the power system. Therefore thereare some factors to be worthy of researching in depth, such as how to choose the control algo-rithm, set the parameters, improve the performance effectively, reduce the economic costs andhow to play to the strengths of the active power filter.Firstly this paper carefully elaborates the harmonic hazards to power system and harmo-nic treatment measures, describes the development status and prospects of the active power a-ctive filter, and introduces classification of active power filter according to different criteria;Secondly, the basic principles and topology of the active power filter is introdued, and it com-pares and analyzes its functional from the DC side, while its three control modes is studied indepth discussion.This paper focuses on harmonic current detection and harmonic control of three-phasefour-wire power system. It has compared the p-q current detection algorithm with the ip-iqcur-rent detection algorithm based on instantaneous reactive power theory, beside theses, thispaper introduces adaptive prediction algorithm (FIR) and combines with the ideal equivalentmodel of the FBD algorithm to solve the three-phase four-wire current detection of power sy-stem. Finally, this paper selects the current hysteresis control to generate the command currentsignal.By studying the traditional theory, the paper also puts up with the new insights that it co-mbine the adaptive prediction (FIR) algorithm with FBD algorithm to detect the harmonic cu-rrent and compensate reactive power to ensure the stability of the power quality.Finally, this paper sets up the simulation model of the parallel three-phase four-wire acti-ve power filter in the MATLAB and chooses the control strategy and the harmonic currentdetection algorithm. The result shows that the feasibility and effectiveness of this design.