The Theory And Application Research Of Shunt Hybrid Active Power Filter

As the traditional harmonic canceling tool, Passive Power Filter(PF) is replacing by some new equipments for its several insuperable disadvantages, such as the more possibility of resonancing with power ner and the simplex filtering perfonmance. Hybrid Active Power Filter(HAPF), combined the merits of Active Power Filter(APF) and PF, is becoming the researching focus of harmonic eliminating and reactive power compensating equipments. Based on the project of harmonics suppression and Var compensation in a copper foil factory in Jiang Xi province, this dissertation expands the structure, principle, detection and control method of HAPF, as well as the optimum design means of main parameters and some important realizing technologies. The emphasis and achievement of the paper mainly manifests in the following aspects:1. By the establishment of the universal electric model, the thesis carries on an comparative investigation into the filtering principle based on several kinds of basic control strategies and presents a viewpoint that we should choose the best control stratege by detailed analysis of the local situation to minimizing the negative influence of filtering performance, which caused by power parameters fluctuation.This paper presents the universal electric model based on the detailed analysis of the configuration of the several normal HAPF. It helps to the uniform research of different sort HAPF. By the establishment of the electric model, this paper carries on an investigation into the harmonic filtering principle of shunt HAPF based on several kinds of its accepted basic control strategies. Further more, a comparison research, which focuses on the influence of shunt hybrid active power filter operating performance, produced by different control strategies, is put forward considering the change of power network parameters . The conclusion may help to the optimized choice of the basic control strategy under the complex operating mode and guarantee the security operation of the whole system.2. The dissertation analyses the reason and its affect of HAPF system time delay. Based on it, a series means of minimizing the influence which caused by this delay is put forward to improve the performance of the filter.The research shows the system time delay exists in every part of digital signal processing flow. In it the delay caused by digital signal distribution is the most important one. This dalay is not only negative to the filtering performance but also easy to magnify some high harmonics. At the same time it would influence the PWM modulation based on sawtooth wave. Taking it as the foundation, this paper also presents some methods to reduce the delay and gives a introduction about the methods applying in HAPF. The ways include selecting the high speed A/D chips and microprocessor, adopting the current and voltage transformers which have the function of phase compensation, improving sampling frequency and compensating the dead-time effect. Furthermore, applying signal forecast method is another effective way to minimize its bad influence.3. According to the necessary analysis of frequency dividing control in HAPF, this dissertation presents a fuzzy-PI control method based on generalized integrator. In this way a effective frequency dividing control method, which simplified the frequency dividing detection part in the control flow, is realized.By the analysis of the special configuration characters a conclusion is put forward that a frequency dividing control method should be adopted in HAPF. Because the active part of HAPF is connected with Passive filters directly or there are some another parallel Passive ones in the circuit, it is unnecessary to control some certain orders harmonics. Moreover, the amplitude changes and phase excursions are not same between the different order harmonics during the process of compensated harmonics injecting. Ground on the above principles, this paper presents a fuzzy-PI control method based on generalized integrator to realize the frequency dividing control of HAPF. In this mean generalized integrator is used for frequency dividing integral and fuzzy arithmetic is for adjusting PI coefficients timely. Compare with other kinds of control methods, the proposed one is more simple and easier realization. The shorter response time and higher control precision are also the advantages of it. Simulation and experiment shows the method can meet the harmonic suppressing requirement of the HAPF controller.4. Based on the project of harmonic suppression and Var compensation project, this paper presents a way of system parameters design and a typical applying blue print in HAPF. As the example of resonance injection HAPF, this paper puts forward a series design methods of configuration and parameters in large capacity HAPF. In them fuzzy and genetic algorithm are introduced to implement the optimal design of multi-object.According to the research result of filtering principle, signal dection, control method and parameter designing means in HAPF, the dissertation brings forward a series of applying blue print which is right suitble for the large capacity harmonic suppression and reactive power compensation project. Based on the project in a copper foil factory in Jiang Xi province, the paper contains several key technologies in implement HAPF, which including design simulation, equipment selection, software and hardware design. It would help to the spreading application of HAPF in china.