Research On Hybrid Capacitors Switching Static Var System Of Submerged Arc Furnace

Industrial submerged arc furnace is both typical high-energy-consumption and non-linear user. The operation of submerged arc furnace needs to absorb a large amount of reactive power, and also begets serious power quality problem, such as harmonics, voltage fluctuations and three-phase umbanlance and other power quality disturbance pollutions. With more attention has focused on energy conservation and power quality, submerged arc furnace and electricity sectors also take more attention on developing and using cost-effective reactive power compensation. Hybrid capacitors switching static var system(HSVS) takes advantage of capacitor reactive power compensation’s economic superiority,dynamic characteristics of solid state switch and low loss of mechanical switch, is used as a high efficiency reactive power compensation device of submerged arc furnace,HSVS became a research hotspot of reactive power compensation of submerged arc furnace. Theoretical and technical problems that relates to Hybrid capacitors switching static var system(HSVS) which is concentrate on reactive power compensation is studied, has the significance theory importance and practical application value.Firstly, the paper describes the current situation and development trend of submerged arc furnace’s reactive power compensation technology and analyzes the structure and electrical parameters of its power system. Establishes the electrical model of each component of the submerged arc furnace power supply system.Secondly, components of HSVS such as mechanical switched capacitor (MSC), rolling switched capacitor(RSC) and thyristor switched capacitor(TSC) have been discussed. This paper studied working principle and main circuit physical structure of HSVS. The methods that are used to calculate the capacity of reactive power compensation such as power factor method, reactive voltage method improved matching flow injection method and economic optimization algorithm have been discussed, the capacity optimization assignment method of MSC, RSC,TSC is also explored.In this paper,ip-iq signal detection method which is based on instantaneous reactive power theory has been studied. Improved nine zones control strategy of hybird switching capacitor reactive power compensation system is also studied.Lastly, this paper used simulation software MATLAB to simulate the working principle,signal detection and control strategy of hybrid switching capacitor reactive power compensation system. And the main circuit and controller of low voltage hybrid switching capacitor reactive power compensation system have been designed. In the designing of main circuit, the selection of capacitors, mechanical switches, solid state switches and reactor has been analyzed in detail. In the designing of controller, the hardware circuit design and software development based on STM32F407VGT6 have been deeply studied.The low voltage hybrid switching capacitor reactive power compensation system is also designed in this paper and has been successfully applied in a submerged arc furnace reactive power compensation in Yunnan.Theoretical research, simulation result and practical application of hybrid switching capacitor reactive power compensation shows that the hybrid swtiching capactor static var compensation system applied in this paper is a cost-effective superior reactive power compensation device.