Theory Research Of The Voltage Type Unified Power Quality Controller (upqc)

With each kind of electric appliance equipment popularization, the dependence on electrical energy is more and more serious.Because of the electric appliance equipment diversification, non-linear load in electrical network increases day by day and cause serious influence on electrical energy quality. In order to meet the users needs, improveing electrical energy quality which the electrical power system provides, has already become the electric power research work important content. In the existing technical scope, there are very many methods possible to enhance the electrical energy quality. We can compensate the overtone and the idle current in the electrical network by using active electric power filter (APF),which is simple quickly and the results are precise and highly effective,and which is the present most effective method.This article has conducted preliminary research in view of the influence on electrical energy quality on each kind of factor and brief analysis has been made to inhance the electrical energy quality.Simple discussion has been carried on the active electric power filter development course and the research at present.The active electric power filter development course and the research present situation has also been carried on the simple discussion,which is the key point in electrical power system research at present. Mixed active electric power filter,which is called unified power quality controller (UPQC), has been launched the detailed analysis to its topology and the compensation characteristic in this article.Research has been conducted to the voltage and the load current process in the UPQC compensation system.Based on the main circuit topology, the parallel part have been carried on the function decomposition and the corresponding mathematical model has been established respectively.After the research discovery, the prerequisite to the accurate compensation in the electrical power system is wether the overtone and idle current can be precisely examined in Electrical power system. Therefore, how to precisely examine the overtone and the idle current has been carried on the key introduction in this article.However,many voltages are assymetrical in electrical network,and precisely examinations to distortion profile are very difficultly in the distortion situation.Only the overtone examination method based on the Park transformation can examine,which also does not need to the three-phase voltage to carry on the phase-lock or the bandpass filter. Thus this article mainly uses this method. How to choose the control method is the UPQC key technologie. Detailed introduction and the contrast have been carried on in his article to merits and shortcomings of each kind of control methods used commonly at present,including the voltage, the electric current follow-up control as well as directed current the side voltage control strategy. In the article stagnates the link comparison control method is used in the parallel part, but the triangular wave comparison control method is used in the series connected part.In this article,based on the main circuit topology,corresponding parameter has been calculated,simultaneously low pass filter (LPF)has been designed.And optimized choice unified the MATLAB simulation software has been carried on to each data, finally the simulation to UPQC has been carried on according to the data which isexamined by using the MATLAB simulation software. The simulation result discoveres UPQC can be the very good realization to the load input voltage and the input current integrated control.The examination and the control method used in this article are extremely effective.