Research On Static Synchronous Compensator In Power Distribution Systems

Static Synchronous Compensator, STATCOM in short, is a crucial component of Flexible AC Transmission System (FACTS). Having becoming a hot subject in modern reactive-load compensation study, STATCOM, with its relatively good regulating property, is capable of compensating reactive power in the system with a faster speed and a higher efficiency. STATCOM applications in power systems is an attempt to solve the conflict between daily increased power consumers and the finite source of power networks, and to solve power quality problems caused by a large number of nonlinear new power equipments and other reasons as well. By far, the studies and applications about STATCOM are emphasized on large capability and high voltage devices. This paper describes the STATCOM of power distribution systems. The typical objects of distribution STATCOM are reactive-load compensation, node-voltage stability, and dynamic characteristics for special loadsOperating principles of reactive-load compensation devices usually used and their differences in structures and regulating characteristics are briefly introduced, whereas operating principles, circuit structure and specific applications in improving electric energy quality of STATCOM are analyzed in detail, adopting three-level voltage inverter as the main circuit, comparing different schemes of reactive-load compensation and choosing the tracking compensation to calculate the compensation capability. Based on switching functions of the three-level voltage inverter, the dynamic model of inverter DSTATCOM is discussed and the theoretical selecting principles of parameters of the model are analyzed in the thesis. At the meantime, the hardware structure of controller based on DSP slug including the design of synchronous circuit, measuring circuit and driving circuit and protective circuit and others is designed in this dissertation. Referring to the features of low-voltage distribution system, the paper bears the function of analyzing the control strategy of the inside power double-make circle on the basis of predictive control. The circuit controller is accordingly designed. The main circuit inverter models in the compensation device and artificial circuit are constructed in the article with MATLAB/SIMULINK emulation tools being applied. Output inactivity and side voltage of direct current are controlled by respective PI control strategy and predictive power control strategy with the artificial analysis of DSTATCOM of its dynamic compensation in the capacitive and perceptual inactivity while the respective DSTATCOM features in PI control and predicted power control are compared.The simulating results prove the control strategy of the inside power double-make circle on the basis of predictive control put forward in the dissertation can realize dynamic compensation effectively.