The Detection And Treatment Of Power System Harmonics

With the fast economic development, a mass of power electronic equipments are accessed as resulting in the harmonics in power system. On the other hand, precise instruments and digital equipments provoke higher requirements on power quality. Therefore, the detection and effective treatment of power system harmonics is of great significance.The dissertation introduces the related definitions, adverse effects of the harmonics and the main control measures, analyzes thoroughly the structure, classification and operating principle of Power Filter and Active Power Factor, compared the advantages and disadvantages of all kinds of filter. Afterwards, the paper discusses the harmonic detection methods, controlling methods, and designing the main circuit of Active Power Factor and other respects in detail. As for the harmonic detection, the thesis discusses the p-q harmonic detecting methods and ip,iq harmonic detecting methods and proposes a new harmonic detecting method based on Least Mean Square(LMS) which improves the performance of accuracy and real-time. As for the harmonic treatment, this thesis analyzes control strategy of Active Power Factor, control methods of current tracking control circuit, voltage control method of DC side. Based on the theoretical analysis, a simulation model of parallel hybrid Active Power Filter using MATLAB simulation platform has already been established, and the optimal design of this type of filter has also been realized by a series of simulation. The simulation results show that the parallel hybrid Active Power Filter can quickly detect and effectively the harmonics in power system.