The Study For Static Synchronous Compensation Based On IGBT

With the development of the power electronic technology and continuous improvement of power quality for power equipments, reactive power compensation of power quality is becoming more and more serious. At present, the power system is lack of var compensation, furthermore most compensation methods for the compensation devices are not good enough to meet the requirement of compensation for power system. STATCOM is an appropriate solution of these problems. Heretofore, the studies and application about STATCOM are emphasized on large capability and high voltage devices. The paper focuses on STATCOM in the low-voltage distribution system, and proposes STATCOM compensation plan for low-voltage distribution network.For overcoming the unfavorable influence which is brought by non-ideal electric network voltage when detects the reactive current, this paper puts forward a reactive detection method which is based on coordinate conversion on revolving coordinate system for network voltage and current, to realize the extraction of reactive current, and then improve the detection accuracy. And base on topological structure of STATCOM for three-phase three-wire system, it puts forward a control method of compensation current which is based on forecasting current strategy to improve the tracking accuracy of dictation current.The digital simulation model of STATCOM system is established, and the system is emulated by MATLAB/Simulink software. The emulation certifies the good reactive compensation performance of the equipment desigend, and shows that the accuracy and feasibility of detection method and control strategy proposed.The hardware of STATCOM is designed. The work includes the selection of main circuit components and control chip, the designs of measuring circuit, control circuit and electrical source circuit. The control software program is compiled by C language .The hardware and software constitutes STATCOM device.