Application Of Hybrid Reactive Power Compensation In Variable Frequency Speed Regulation System Of Rolling Mill

In recent years,with the development of power electronic technology,high-power nonlinear power electronic equipment has been widely used in the power grid.The harmonics generated during its operation will cause serious pollution to the power grid.At the same time,under the influence of a certain impact load,Power quality problems such as three-phase imbalance,large voltage fluctuations,and large reactive power impacts frequently occur,which have adversely affected the power supply system.Therefore,comprehensive management of power grids and reducing the economic loss caused by power quality problems is a must to consider in actual engineering applicationsIn order to effectively solve this series of problems,the article adopts the SVG+FC hybrid reactive power compensation scheme.On the one hand,FC is used to filter out characteristic sub-harmonics and compensate for the fundamental reactive power of fixed capacity.On the other hand,SVG is used to balance the reactive power generated by load changes in the system.In this way,it not only realizes dynamic reactive power compensation,reduces the harmonic content,but also greatly reduces the overall cost.First of all,the article introduces the AC-DC-AC variable frequency speed regulation system commonly used in metallurgical enterprises and studies the harmonic characteristics of its variable frequency devices.Through the analysis of harmonic control measures,the filter compensation plan is proposed under the consideration of reactive power compensation.Secondly,the two traditional reactive power compensation devices of SVC and SVG are analyzed in detail,and various advantages of SVG are obtained through performance comparison;after comprehensive consideration,the SVG+FC hybrid reactive power compensation scheme is finally selected.Analyzing the working principle and compensation characteristics of this hybrid reactive power compensation device and establishing a mathematical model for it;In the case of determining the overall control strategy of the hybrid dynamic reactive power compensation system,the hardware and software circuits of the SVG and the FC filter branch are designed.Finally,According to the mixed reactive power compensation scheme of rolling mill power supply system in Masteel heavy H-beam production line,the parameter design,device debugging and power quality test and analysis are carried out.The application of engineering examples proves that the hybrid compensation of static var generator SVG and passive filter device FC can effectively eliminate the adverse effects of AC variable frequency speed regulating devices on the power grid and reduce power loss.