Harmonic Analysis And Its Attenuating Method In Typical Power Supply System

Power quality as one of the important criterions for high-efficiency and safety operation of the utility grid can determine the cost-reduction and efficiency-improvement of the industrial production. The safety operation of the grid is even considered as one of the national security. Power electronic switches are widely used in industrial and civil areas, which will cause serious harmonic pollution to its distributed network due to its non-linear switching operation. Eventually, it will cause the electrical equipment operate under low-efficient condition, and even cause power failure in large areas.In this paper, the integration attenuation strategy is proposed to settle the problem of harmonic current and low-power fact of the distributed network caused by the 6-pulses and 12-pulses rectifier which are widely used in copper manufactories.Firstly, the brief induction of the causes of grid harmonics and the meanings of its attenuation is conducted in the first chapter. And the recent studies on harmonic attenuation strategies are also introduced in the first chapter. Secondly, the characteristics of the harmonic generation of the 6-pulses and 12-pulses rectifiers are analyzed by theoretical and simulating analysis. And the common and special characteristics are analyzed. Next, in order to extract the harmonic components with fast speed in the case of asymmetrical grid voltage, the discrete Fourier sliding iteration with p qi ?i sampling method is proposed for active filter equipment. Then, the integration attenuation strategy based on single tuning harmonics circuit and intelligent var compensator(IVC) is proposed for 6-pluses rectifier to tackle the problem of current harmonics and low power factor. Also, the integration attenuation strategy based on single tuning harmonics circuit and the active power filter is proposed for 12-pulses rectifier to tackle the problem of current harmonics. The simulation results confirm the feasibility of the proposed strategies. Finally, the summary is conducted in the last chapter.