Modeling And Simulation Of Passive Dynamic Harmonic Filter

Electricity is one of the most important energies in our country. But the quality of it has been worse, for more and more nonlinear loads connected to the power system lead to the imbalanced reactive power consumption and harmonic generation. So reactive power compensation and harmonic suppression are extremely urgent. The major reactive power compensation equipments have some shortages though effectual. Harmonic suppression is mostly to install the harmonic filters. The filters can also compensate the reactive power. Passive filters are more simple, convenient, inexpensive, with higher reliability and easier installation when compared with active filters. So passive filters have been extensively used. But they also have some performance deficiencies. For this reason, my project team points out to design a kind of passive dynamic harmonic filter based on SCR variable reactor. This article is to build the system simulation model of passive dynamic harmonic filter on MATLAB/Simulink, and verify the tuning reactive power compensation and harmonic suppression performance.After analyzing the topological structure and operation principle of the traditional passive harmonic filter, some performance deficiencies, especially the tuning performance, have been pointed out. In order to make up those deficiencies, the topological structure of a kind of passive dynamic harmonic filter based on SCR variable reactor has been proposed, and the principle of it has been analyzed.In order to verify the tuning reactive power compensation and harmonic suppression function, the system simulation model consisting of three phase power supply, nonlinear load and passive dynamic harmonic filter has been built on MATLAB/Simulink according to the system simulation structural diagram. So it has laid foundation to the simulation and analysis below.The simulation and analysis are done on the system simulation model of passive dynamic harmonic filter. During the simulation, firstly simulate and analyze the reactive power and harmonics of the system before filtering. Secondly determine the parameters of passive dynamic harmonic filters. Thirdly connect the filters to the system to simulate and analyze the effect of reactive power compensation and harmonic suppression. And at last analyze the tuning performance of the filters which include simulation and analysis of avoiding overcompensation and dealing with the capacity of the capacitor reduced.Simulation results show that on the fundamental frequency the passive dynamic harmonic filter can compensate the system’s reactive power and on the harmonic frequency it can absorb harmonics. At the same time it has tuning reactive power compensation and harmonic suppression functions:When overcompensated, the capacitors can be partly on-off and the inductance of the variable reactor can be adjusted so as to dynamically tune to avoid overcompensation; and it can dynamically adjust the resonance frequency of the filter after the capacity of the capacitor reduced so as to keep the precision of harmonic suppression unchangeable.