Research And Implementation Of Static Var Generator In Disteibution Network

In this dissertation, according to the background which the diversity of load leads to serious deterioration of power quality in the low-voltage distribution network; we introduce the research significance of the subject, and analyze the effect of reactive power to the low-voltage power system and the development trend of reactive power compensation technology and equipment at home and abroad. The SVG technology and equipment, which is current research hot spots, is analyzed and researched in detail.We explain the principle of voltage source topology’s SVG, and create the mathematical model of SVG. The vector detection algorithm based on d qi-i transform of the instantaneous reactive power theory is also analyzed in detail. We utilize the method of T4 delay to separate the component of the positive and negative sequence and then adopt the SPLL to ensure the real-time accuracy of reactive current detection. Furthermore, we carry out the contrast between the triangular wave comparison and hysteresis control principle in the indirect control and direct control of SVG. To improve the control performance of SVG, we design a double closed loop control strategy which consist of a DC PI voltage outer loop and a AC PR current inner loop of without decoupling based on the advantages and disadvantages of the traditional PI control and the characteristics of the PR controller without static error. By the theoretical research to SVG, the main circuit parameters were calculated and selected based on the requirements of the design. Then, we build the model of SVG system by utilizing Matlab software. The results of simulation show the effectiveness of the improved control strategy.Finally, we design the hardware circuit and software program flow for the SVG system, and carry out the experiment by utilizing the Experimental platform based on DSP28335 as the control core. The experimental results verify the feasibility of the SVG system.