Analysis And Study On Power Network Var And Compensor

There are no more than two methods to solve the problems of harmonic component and low power factor;one method is to install compensatory equipment,such as filter with electrical source,reactive power compensator,etc,try to control the harmonic component and compesate the reactive power;the other method is to improve the epuipment of electric power themselves,make it not produce the harmonic component and not use up reactive power.It needs to renovate the epuipments of electric power largely with the last method,cost a lot, limit its feasibility.The first method is the same with all kinds of equipments of harmonic component sources and low power factor,and the methods is simple,it has broad application.This paper shows the fundamental principle of var compensation through the narration about var compensation's development process and the practical application(including TCR,TSC and so on).After comparing the dynamic var compensation with other compensation methods,the dynamic var compensation has the superiority of high reliability,flexible control,low requirements for the volume of capacitor and small connective reactance.The paper describes the theory of dynamic var compensator(basic principle and working principle).Because dynamic var compensation change DC link into AC link(same frequency with the power network) when it works on the normal operation,dynamic var compensation just likes a voltage inverter.The difference is that its AC side output is connected to power network not passive load,therefore,when only considering fundamental frequency dynamic var compensation can be looked as a voltage source(same frequency with power network).Presently,the application of SVC with dynamic compensatory capability is more and more,but the biggest disadvantage of it is that the compensatory capability is limit by the capability of themselves,and produce large harmonic components when send and cut the capacitors.The other method with dynamic compensatory capability SVG,its characteristic breaks away the characteristics of impendance,become the absoluted voltage source or current source,improve the performance of reactive power compensation,and it has strong control ability towards electric network.Then base on the laws and characteristics of Liao River Oilfield power network var,find the adaptive compensation method and make the hardware design of dynamic var compensation.The hardware includes main circuit(DC link capacitance,AC link filter,IGBT,inverter etc),detection circuit of current,detection circuit of voltage,and synchronization signal generation circuit.Establish the mathematical model of dynamic var compensation and research on the change of var current and voltage,which inpour the mount point under the condition of installing the SR or dynamic var compensation as the same volume.Using Matlab software to simulate the dynamic var compensation system.Abstract.