Research On Key Technology Of Low Voltage Reactive Power Compensation

With the rapid development of power grid, the grid scale andcomplexity have been greatly improved, reactive power andharmonic and batch input caused by nonlinear devices, further influence thequality of electric energy, bring about more challenges to reliable operation ofpower network. TSC is reactive power compensation current widelyused, with the advantages of simple structure, low cost of outstandingperformance; Static var generator (SVG), with smooth, reactive power torapidly adjust outstanding performance, is the scientific research andengineering areas of concern. And the thinking of SVG and TSCcombination, not only can meet the need of dynamic performance, and mostof the capacity of SVG is replaced by TSC, the cost can be greatlyreduced.This paper will take SVG+TSC as the research object, the principle andkey technology (control strategy, control method and software and hardwarerealization of the following research): First, several kinds of circuit topology structure of SVG is introduced inthis paper, the working principle of voltage type SVG is discussed, andthen the indirect current control of SVG, the direct current control areanalyzed and compared the control strategy. At the same time the reactivecurrent detectionmethod of instantaneous reactive power theory is definedbased on the research and analysis.The circuit topology of voltage type SVG as the foundation, building amodel of control system, the rotating coordinate system as a tool, the activecurrent of IP, the coupling relationship between reactive current IQ isanalyzed, the method of decoupling, the independent control of reactivecurrent and active current, Based on the research of SVG DC side voltagecontrol method of double loop control model, is proposed based on vectorcontrol. At the same time, using MatLAB as a tool for the simulation research,the correctness and feasibility of the control method is verified.Analysis of TSC reactive power compensation principle, the controlstrategy is studied,researthing the switching oscillation, and solutions aregiven in this paper, the application of MatLAB is verified by simulation.Study on control strategy for SVG+TSC portfolio, given the configurationscheme of the system, set up the hardware and software system. The circuit uses DSP and CPLD as the hardware core of the system design, including theAD sampling circuit, a compensation circuit, I/O control circuit, interfacecircuit,communication etc.. Main program and each functional module ofsystem software is developed in TI environment. To construct a SVG+TSChardware experimental studies were carried out on the controlsystem. Experiments show that, the SVG+TSC system function is stable andreliable, has reactive power compensation effect and efficient.