The Research Of Currenr Detecting And Control Strategy Based On Static VAR Generator

Recently, Flexible AC Transmission Systems have been widely researched and developed as an efficient technology to improve electric power quality. As one of key technology of FACTS, Static Var Generator (SVG) has been the hot research topic of today's Flexible AC Transmission equipment because of its effective control and good compensation performance.Based on the low-voltage distribution system or load compensation for industry, the aim of the thesis is to study the SVG that adopts direct-current control.First, this paper summarizes the development situation and trend of SVG, analyses operating principle. Then, introduces the current detecting methods of reactive power, does some optimization in test part, introduces the procedure of the filter in detail, and an improving detecting method used to computation is proposed to eliminate current detecting error when the voltage is distorted or unbalanced. Simulation and experimental results are presented to verify the method is simple and applicationable. Introduces the strategy of SVG, and reactive power compensation strategy based on direct current control has designed, then does the corresponding simmulation. Last, to reduce switching frequency and loss, a three-level hysteresis control method is put forward in this thesis. Simulation results verify the merits of the three-level hysteresis control method:low switching frequency, little dynamic loss. So it can improve the efficiency of the whole equipment.A SVG experimental system based on the controller-TMS320LF2407A DSP has been built, and some experimental research has been done based on it. The experimental results are presented to verify the anticipated performance of this SVG system:quick tracing and good compensatory performance.