A Study On Harmonic Restraint Of The Power Supply & Transmit Electricity System In Guangyuan City

With the quick development of the industry and agriculture, the category of electric power system gradually increases. Consumers successively plunged a large number of silicon controlled commuted devices (such as steel rolling ,electrized locomotive,aluminium electrolysed devices etc) and smelting devices to improve their produced efficiency or to save energy. On the one hand it is good for consumers, on the other hand it will arouse the fluctuation of voltage and frequency and it will result in the collision of the active and reactance capacity. Meanwhile these nonlinear loads bring much harmonic into the electric network which deteriorate the quality of power supply and hazard the online device enormously. The power Supply & Transmit electricity system in GuangYuan fulfilled the role of supplying main power to GuangYuan city. While the harmonic occurred is very serious and it has not been restrainted.The main harmonic sources are two loads: aluminium electrolysed load and electrized locomotive load. The engineer of the Electric Power Science Academy tested the harmonic occurred in 220KV transformer substation in BaiShiYan,110KV transformer substation in NanTuPo ,110KV transformer substation and converting station in 821 factory. This article analyzed these data particularly. The three-phase commuted device of 821factory is one of the main harmonic in the power Supply & Transmit electricity system in GuangYuan. This article analyzed the three-phase full-controlled bridge commuted circuit ,the three-phase half-controlled bridge commuted circuit and the harmonic occurred by the two circuits. Through the analysis to the relative merits of the Passive Filter and Active Filter, a new applied harmonic current compensation device was presented in this article. This device was made up of a Active Filter and a High-PASS Passive Filter.Electric railway traction load is the high-power one-phase commuted load that fluctuate largely. For the power supplying of electric system it has the following feature: unsymmetry ,nonlinearity,freqence,high-power,wild-distribution. It is one of the main harmonic in the power Supply & Transmit electricity system in GuangYuan. This article analyzed the electric railway traction load and the harmonic occurred by it. This article used SVG(that is Static Var Generator)to restrain harmonic and negative sequence current by the comparison of SVC with SVG.