Research On STATCOM Based On DSP In Distribution System

As the dynamic reactive power compensator, DSTATCOM (Distribution Static Synchronous Compensator) is one of the emphasis problems in power system in recent years. The difference between DSTATCOM and traditional reactive power compensators is compared and the predominance of DSTATCOM is analyzed. The study actuality of DSTATCOM in home and abroad recently is recounted.The voltage type circuit and current type circuit of DSTATCOM are pointed out. The operation principle of DSTATCOM based on voltage type circuit is particularly analyzed in this paper. It can be seen that the function of DSTATCOM is better than traditional reactive power compensators such as SVC (Static Var Compensator). The mathematical model of DSTATCOM based on switching transfer functions is built.On the basis of analyzing the concept of reactive power theory in non-sine circuit, the concrete process of detecting reactive current using the method of 'ip,iq calculation' of transient reactive power theory has been deduced. The control method of DSTATCOM has direct control and indirect control of current. The bivariate variable coordinated control scheme of indirect control of current is adopted, in which prediction +PI control mode is adopted in reactive current control and tradition PI control mode is adopted in DC voltage control. SVPWM modulation mode with which the DC voltage utilization ratio is high, the switch wastage is small and the harmonic content is low is adopted in producing the pulse wave.The experimental device of DSTATCOM is built whose control core is TMS320LF207A of TI company and whose circuital voltage source converter is integrated IGBT intelligence power module (IPM). The control scheme presented in this paper is debugged and studied in the device. From the experimental results it can be seen that the dynamic performance of prediction +PI control mode in reactive current control adopted in this paper is better than that of tradition PI control mode in reactive current control. The function of DSTATCOM device has basically reached the design demands.