大型电弧炉无功补偿与谐波抑制的综合补偿系统

针对大型电弧炉引起的电压闪变、谐波污染和功率因数低等电能质量问题，提出了一种由静止无功补偿装置与有源滤波器构成的新型综合补偿系统。用静止无功补偿装置快速补偿无功，并通过对其三相不对称控制来改善电网三相不对称和消除负序电流，有源滤波器滤除电弧炉和静止无功补偿装置产生的谐波。通过构造合理的拓扑结构，可使静止无功补偿装置与有源滤波器互不影响，从而实现对其分散控制。将该系统投入实际运行，对比分析了系统投入前后的波形和数据，证明了该综合补偿系统对改善电网电能质量的有效性和可行性。

Comprehensive Compensation System Combining Reactive Power Compensation and Harmonic Suppression for Large-Scale Electric Arc-Furnace

Due to the voltage flicker,harmonic pollution and low power factor caused by large-scale electric arc-furnaces,power quality is deteriorated.To solve this problem, the authors propose a novel comprehensive compensation system constituted by static var compensator(SVC)and active power filter(APF)to implement on-site power quality control. The SVC is used to compensate reactive power quickly and to remedy three-phase asymmetry extent and negative sequence current of power system by means of three-phase asymmetrical control of SVC;meanwhile,the APF is used to filtrate harmonics caused by both electric arc-furnaces and SVC. Using reasonable topological structure,it is possible to avoid the interaction between SVC and APF,thus the decentralized control of them can be realized.The proposed comprehensive compensation system has been put into operation in a certain steel plant,by means of comparing and analyzing the waveforms and data before and after the proposed system put into operation,the effectiveness and feasibility of the proposed system in the improvement of power quality are proved.