Aplication And Research On The Soft-switching Technology Used In The The Main Circuit Of D-STATCOM

In the Power distribution system, due to the existence of the inductor, capacitor components and nonlinear components, there are a lot of reactive power and the harmonics, not only increasing the loss of power, but also a threat to the safe operation of the grid. D-STATCOM in distribution network is a good solution to reactive power and harmonics, improving the static, dynamic and transient stability of the system, strengthening the power oscillation damping and stability of the grid, therefore, D-STATCOM will also be more extensive, as the high-power power electronic devices, D-STATCOM also exists a large switching loss power, High Current and Voltage Impulse, serious EMI and so on. How to solve the problems. The emergence of soft-switching technology provides a way to solve this problem, Soft-switching greatly reduces the switching losses, the impact of the Current and voltage impulse and EMI,with the additional inductor capacitor or the auxiliary inductor capacitor.This paper discusses the application of the soft-switch technology to the D-STACOM, first,describe the soft-switching types and the basic soft-switching circuit, and then, deeply Analyze the mathematical model of the main circuit of D-STATCOM, the calculation method of the main circuit are given,and its simulation, Finally, we discuss the soft switch structure for the main circuit of D-STATCOM, and its simulation.