Equipment Development And Engineering Application Of Shunt Hybrid Active Power Filter For Low Voltage

With the background of grid harmonic issue in a large Copper Co., Ltd, HeFei,the paper aims at studying on a power quality control device to suppress theharmonics in low voltage distribution network, which combines the passive filter withactive filter, taking the advantage of passive filter low-cost, simple structure, andusing the active filter to achieve harmonic current real-time tracking and dynamicsuppression; as a result of multiple harmonics suppression at the same time; so thisequipment improves the power quality of low-voltage distribution network greatly.Firstly, this paper presented the causes of harmonics in low voltage distributionnetwork, analyzed the disadvantages of harmonic current and the significance ofharmonic suppression; compared the methods of harmonic suppression both here andabroad, mainly described the development of the power filter.Secondly, a detailed theoretical analysis and simulation had been carried out todeal with the harmonic issue of this enterprise, with which the rectifier harmoniccontent and power factor had been calculated; the paper proposed two sets ofsolutions both combined passive power filter (PPF) with the active power filter (APF).Simultaneously, the parameters of the solutions had been set to analyze the overalleffect of simulation and harmonic amplification characteristics, the results verifiedthe feasibility and practicality.Thirdly, two methods of harmonic current real-time detection algorithm werepresented, which are the most commonly used in active power filter. This paperfocused on the theoretical analysis of two different control methods, showing the ruleof picking the current inner loop PI controller and the impact of selecting parametersKPand KIon system performance analysis. Taking the fluctuations of the grid voltageinto account, it provided a specific way to achieve deadbeat control method based onthe composite correction. The simulation result proves the validity and reliability ofthe proposed methods.Fourthly, on engineering application background of APF, the integral part of thesystem was recommended; the performances of the system under two different controlstrategies were compared; and the hardware design and the software design weregiven respectively. The anti-interference and the problem of heat dissipation duringthe experiment were elaborated. Lastly, a harmonic control device was developed due to those design ideas, with which the grid current distortion rate of the mill wasreduced; the correctness of the design ideas was verified; and the goal of designingwas reached.Fifthly, in connection with the problems in lab design, this paper carried outsome solutions and made a detailed introduction, from detection to solution,experimental demonstration had been carried out. It also proved the rationality andvalidity of the proposed solutions.The practice has proved that the proposed design effectively can reduce the gridcurrent distortion rate and improve the power factor; the device is low-cost, easy toprotect, and stable in operation, which brings the significant economic and socialbenefits to the enterprise. At the same time the design ideas and engineeringexperience are useful references for the practical process of the grid active powerfilter for low voltage distribution.