Study Of Distribution Static Synchronous Compensator Controller

With the development of the technology of compensating the reactive power, DSTATCOM is in great need in research on modern static reactive power compensation because it is the important reactive power compensation device in customer power system, especially with bidirectional compensate timely.On the basis of the analysis of existing principles of DSTATCOM, this paper studies and summarizes its way of compensation, detection system and control methods. Through comparing technological scheme of reactive power compensation in distribution power system, collective compensation scheme under low voltage is selected and the capacity of var compensation device is calculated. The dynamic model of DSTATCOM based on three-level voltage inverter is established by way of lead-in switch function; meanwhile, principle of selecting main model parameters is discussed in the thesis. Detection means and control method of DSTATCOM are focal point of this research. The dissertation determines the detection means of improved d-q transformation theory of vector control based on instantaneous reactive power and presents the double loop control method which combines the control ofpredictive current, PI control with d-q transformation. Moreover, using SIMULINK, a simulation tool of MATLAB, this paper constructs a MATLAB model of detection and control for DSTATCOM. By means of a 10/0. 4kV distribution system with DSTATCOM, it analyzes dynamic compensation of the DSTATCOM during change in the load and compares the performance of DSTATCOM under the control of predictive current and direct current. The simulating results prove the DSTATCOM put forward in the dissertation can realize dynamic var compensation effectively. Finally, the software structure of controller based on DSP (TMS320F240) is designed in this dissertation, so the control strategy of total digitization is realized really.