Research On Control Strategy And Device Development Of Static Var Generator

With the continuous improvement of national economic level,massive use of high-power inductive electrical equipment,the consumption of reactive power increases accordingly,and then cause a series of problems about power quality such as voltage sag,therefore,research on reactive power compensation devices to optimize and compensate reactive power is an important way to make the power system safe and stable.Static Var Generator(SVG)can compensate the reactive power of the system dynamically,so in this thesis,a research solution of SVG with DSP as the core controller is adopted,and a hardware experiment platform is built.Firstly,the specific reasons of problems about power quality caused by reactive power and the necessity of reactive power compensation is summarized in this thesis.Several common devices of reactive power compensation are compared,the thesis analyzes the superior performance and working principle of SVG,and establishes its mathematical model,it lay the foundation for simulation and design of control system about SVG.Secondly,the prerequisite and primary task of reactive power compensation is to detect the reactive current required by the system precisely and real time for SVG.In this thesis,several traditional methods of reactive current detection are analyzed and compared,and the reactive current detection method based on instantaneous power theory is mainly studied,the method of positive and negative sequence current synchronization detection based on d-q coordinate transformation is selected.On the basis of the SVG's main circuit topology and its established mathematical model,the two current control strategies of direct control and indirect control are compared and carried out optimized design,the control strategy of positive and negative sequence current synchronous compensation based on d-q coordinate transformation is selected,and pulse modulation technique using space vector pulse width modulation(SVPWM).The effectiveness of current detection method and control strategy is verified by MATLAB/Simulink simulation.Finally,TMS320F28335 as the main controller of high-speed data processing and algorithm implementation is adopted in this thesis,and designs both hardware and software.The hardware mainly designs the main circuit,drive circuit,signal acquisition and conditioning circuit and protection circuit of SVG;The software mainly designs the main program and the program of related modules.And debugged the experimental platform,the results show that the SVG designed in the thesis meets the performance requirements.The thesis has 53 figures,6 tables,73 references.