链式SVG抑制电弧炉闪变控制策略研究

Study of the Control Strategy of Chain SVG to Restrain the Flicker of Electric Arc Furnace

提出一种基于角接静止无功发生器(SVG)装置抑制电弧炉电压闪变的新方法,通过采样SVG直流侧电压、SVG输出电流实现直流侧电压控制;采样电网电压、电网电流、SVG电流、滤波支路电流通过电压闭环低频闪变检测模块、平均无功电流检测模块、负载谐波及低频闪变检测模块、负载有功比例微分检测模块实现无功指令计算;电流环采用串并联复合重复控制器实现电流指令的快速准确跟踪,从而实现电压闪变抑制、电网电压不平衡补偿、电网电流谐波补偿、电网功率因数补偿功能。现场测试数据表明,SVG投入运行后,电网存在的电能质量问题得到了明显改善,充分体现了SVG对电弧炉负载优越的补偿性能。

A new method of suppressing voltage flicker of electric arc furnace based on delta connected static var generator(SVG)device is proposed.The DC side voltage control is realized by sampling SVG DC side voltage and SVG output current.The sampling grid voltage,grid current,SVG current and filter branch current pass through voltage closed-loop low-frequency flicker detection module,average reactive current detection module,load harmonic and low-frequency flicker detection module and the load proportional differential detection module realize the calculation of reactive power command.The current loop adopts the series-parallel compound repetitive controller to realize the fast and accurate tracking of current command,so as to realize voltage flicker suppression,power grid voltage imbalance compensation,power grid current harmonic compensation and power factor compensation.The field test data shows that after SVG is put into operation,the power quality problems existing in the power grid have been significantly improved which fully reflects the superior compensation performance of SVG for the load of electric arc furnace.