The Study On The Grid Harmonic Control And Reactive Compensation Technology

At present, because more and more power electronic equipments are used in thepower system, which cause the harmonic pollution of power system getting worse andworse, meanwhile a great many reactive power is cost. The active power filter has agood performance in the compensation of dynamic harmonic current, which can meetthe harmonic and the reactive current at the same time, so more and more attention ispaid to it. This paper is just the study of the compensation of the harmonic and thereactive current for the active power filter.Firstly, this paper describes the work principle of the shunt active power filterand establishes the mathematical model according the switch function. Then, do theresearch of the detection method of harmonic and reactive current. The accuracy andthe real-time have an important effect on the compensation effect. Based on thereactive power theory, the traditional current detection method has been proposed inthe paper. Due to the error exist in the situation of asymmetric voltage, an improvedmethod of detecting harmonic and reactive current has been used. The theoreticalanalysis and simulation study shows the possibility of detecting the harmonic andreactive current accurately. Again, in the current control of APF, combined with theadvantages between the space vector control method and hysteresis current control,the hysteresis current control method based on optimal voltage space vector is used,the method has a good dynamic response speed, also reduce the switch frequency. Thecompensation effect is good.The paper design the system hardware circuit by using the DSP(TMS320F2407)as the control chip, analysis from the main circuit and control circuit and also drawthe flow chart of the main part of the software in system. Finally, modeling the entiresystem according MTALAB7.0, the simulation results show that the designed systemmeets the requirements of harmonic and the reactive current compensation.