The Research And Design Of Three-phase Unbalanced Grid Negative Sequence Current And Reactive Power Compensator

In recent years,power consumption and harm caused by negative sequence grid current and reactive power drawn more and more attention.Therefore,how to achieve the effective suppression and compensation of negative sequence current and reactive power become a Research hotspot,however,the control precision and response speed of the existing SVG control methods should be improved,and there are some questions about 2? oscillating current,etc.Negative sequence current and reactive power can not be effectively suppressed and c o m p e n s a t i o n.S o,t h e r e s e a r c h o f S V G c o n t r o l m e t h o d i s o f g r e a t significance and value.First,in order to achieve the suppression of the existing SVG current loop system's overshoot and to improve response speed,one kind of PI control strategy is adopted based on low time constant differential negative feedback and feedforward compensation.For the problem of the increase of the current controller's delay time and control instruction's error by the introduction of trap or filter to achieve the suppression of 2? current oscillations in SVG single current loop controller,one kind of PI control strategy is adopted based on double decoupling control method,and their control effectiveness is verified by simulation test verification.Secondly,the required parameters for SVG control method based on grid system parameters and the expected effect of the compensation claim is calculated,complete hardware experiment platform is build,as well as control circuit board and software programs are debugged,and hardware test is carried out.The results show that,in this paper,double PI decoupling control methods based on the small time constant differential negative feedback and feedforward compensation control method have been proposed to realize the suppression of overshoot and 2? current oscillation and improving the response speed,and it can be valid for the suppression of negative-sequence current and the compensation of reactive power,and achieving the desired design expectations.