Control And Research Of Distribution Network D-STATCOM

For non-renewable energy reduction and the rapid development of the industry, power usage is increasing year and year. Next comes its more and more complex electricity load in distribution network. This caused many power energy problems within network, threating distribution network stability, under serious condition, leading to power network breakdown, bringing huge economic loss. Facing with these issues, D-STATCOM in distribution network has been studied widely. D-STATCOM can not only compensate reactive power, but also suppress the harmonic, which improve the quality of power supply and stability of power network.In the paper, for improving the performance of system, D-STATCOM controller was designed. First of all, the current research of D-STATCOM was narrated, introducing used commonly and advanced control strategy of D-STATCOM, and analyzing the advantage and disadvantage of various control methods. Then, the mathematical model of D-STATCOM was built, acquiring switching function model and duty-ratio model, which provides the basis for control strategy selection and system analysis. From the angle of energy exchange and transmission, the working principle of D-STATCOM was researched and analyzed deeply, and direct voltage control detection method was proposed. Through study on repetitive control theory, repetitive controller is selected as current loop controller of D-STSTCOM, so that, the compensation performance can meet dynamic and static requirements. Finally, D-STATCOM system has been tested in MATLAB,and controller performance has been verified in experimental platform by writing controller program. Simulation and experimental results show that D-STATCOM designed by using competitive control method is of faster response speed, wider operation range, smaller harmonic current and obvious compensation effect.