Research Of Low-Voltage Static Synchronous Compensator Based On DSP

At present,the power system is lack of var compensation;furthermore,most traditional compensation methods for the compensation devices are not good enough to meet the requirement of compensation for power system,so it needs to reaserch the theories of inactive power and research the advanced compensating device.It is a great subject related to such fields as power electronic technology,power system,and electric automation,etc.The theories of inactive power and research to compensating device have borne significant fruit in recent years.STATCOM is used in not only compensating reactive power but also eliminating harm current,and it is desired for saving sources and improving the quality of the power.This paper proposes the STATCOM realization method by using digital signal processor,studying and analyzing it deeply.First of all,this paper introduces the working principle of classic compensation methods and the development of power theory in detail,and the emphasis is on the instantaneous power theory and the STATCOM based on this theory.Then I introduce its working principle in detail,and established STATCOM's equivalent model.On this foundation,this paper established its mathematics model of stable state,and it used switch function law.Based on this viewpoint,this paper discussed the control ways thoroughly.The STATCOM have two control ways,one is the direct current control and the other is indirect current control. Compared with the indirect control,the direct control has more superior performance in current tracking speed and control property.So this paper used the direct current control as well as the technology of SPWM.Based on these scheme established,the hardware and software design scheme of STATCOM are determined.This paper elaborated the design of hardware using IPM, and the design of controller adopting digital signal processor(DSP).It introduces the modular structure of STATCOM's software.On the basis of theoretical studies,I use PSCAD software to simulate the effect of STATCOM,and the simulation results show that the device could be effective in reactive power compensation.So it will be applicable to low-voltage distribution networks and plays its role of reducing line depletion and improving the quality and stability of the power grid operation.