Harmonic sources in the city distribution system

More and more nonlinear loads are being put into city distribution systems. They inject a large mount of harmonics, especially the third, the fifth and the seventh. The harmonic level in the city distribution systems is increasing. In this paper, the harmonic behavior of five kinds of typical harmonic sources (trolleybus converter station, arc furnaces, fluorescent lamps, microcomputers, and TV sets) in the city distribution systems are described according to analysis and measurement, the harmonic effects on the distribution systems, the generators and other electric equipment are introduced, and the harmonic elimination ideas are presented.