Harmonic Resonance Research Of Power System Based On Model Analysis Method

The harmonic is the pollutant of electricity environment, and it must affects the entire electricity environment, furthermore affects the place far from the harmonic source, in which harmonic resonance is possibly one of major effects. When the harmonic resonance comes into being, the harmonic current or the harmonic voltage are magnified to several times, produces the over-current and the over-voltage, forms superheat, and makes the capacitor shelf partial discharging to increase, the acceleration insulation older, possibly causes the equipment damage, and the protection and the automatic device operates by mistake, system out of control, then endangers the system safety movement. This paper investigates the problems because of harmonic resonance.This paper mainly aimed at the electrical network resonance which caused by harmonic, and has carried on the simulation and the confirmation in the three-phase electrical power system. It summarizes single-phase model and the three-phase harmonic model of various electrical elements in the electrical network, with emphasis discussed each kind of wiring transformer model and the admittance matrix, summarizes the electrical power system node admittance matrix formation.According to the model analysis theory which literature [7] proposed, in which the single-phase harmonic resonance model analysis has founded, this paper extended to the three-phase electrical power system resonant model analysis, separately discussed the computation of model indexes and the participation factor when one-phase, two-phase or three-phase harmonic resonance occurs.This paper builds the model in the simulation platform provided with MATLAB to carry on the simulation analysis, establishes the three-phase model of the Xichang sub-electrical network, accurately and simply obtains the impedance-frequency curve of the Xichang sub-electrical network, and the accurate resonance frequency can be founded in the curve. Because the electrical network includes traction transformer substation and the compensation capacity, it carries on analysis before and after the compensation ploughed into, contrastively obtains influence to the entire electrical network of compensation of the traction transformer substation. According to three-phase harmonic resonance model and node admittance matrix analysis which this paper infers, it obtains the diagonal eigenvalue matrix and the left eigenvector matrix, and gains the resonant information, from this the area's size and the intensity influenced by harmonic resonance can be seen. It provides the passive filter design with certain references. The analysis results indicated that, the three-phase harmonic resonance model method can provide some reference information for the three-phase electrical power system resonance, and the further research can be conducted.