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It is well known that the passive filters can be used to improve the harmonic pollution problems in the industrial systems which contain non-linear loads. However, some parallel resonant points could be produced by the filters and the system impedance. If some frequencies of harmonic currents are near the parallel resonant frequencies, the harmonic current amplification problems will take place. This could damage some equipment. Thus, a complete passive filter design scheme that considers the variation of system impedance is proposed in this thesis. The harmonic flows, voltage distortions, and effect on each component (transformers, capacitor banks, filters) will be obtained by this program. If the potential problems of harmonics are examined in advance, the customers will easily use harmonic loads and filters. Besides, this thesis also describes the relationships between the filter''s parameters and the filter characteristics, and particularly in the second order damped filters. The applications in practical filter design are also proposed. At last, the protection schemes of filter are included in the design. The electromagnetic transients program (EMTP) is applied to the simulations of transients during the switching of filters. These procedures will enforce the design process of filters. This thesis studies two practical cases of filter design. One is a plastic plant and the other is a metal factory. These two industrial systems respectively are with rectifiers and arc furnaces. Simulation results indicate that the proposed method could not only solve the amplification problems but also reduce the harmonic pollution and improve the power quality.
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