A Synchronous Static Compensator Improved Second-Order Sliding Mode Control Method

Abstract

The invention relates to an improved second-order sliding mode control method for a synchronous static compensator, which adopts a reactive current controller and a DC side capacitor voltage controller, and the reactive current control adopts a sliding mode controller designed based on a super-helix algorithm, The low-order term introduces a linear compensation term to improve the reactive current controller; the DC-side capacitor-voltage controller adopts a sliding mode controller designed based on the super-helix algorithm, and the designed sliding mode surface introduces linear compensation for the low-order term and the high-order term respectively. Item, DC side capacitor voltage controller. The advantages are: accurate control of reactive power compensation current, no chattering output, improved reactive power compensation current dynamic response capability, improved dynamic response capability of step compensator DC side capacitor voltage, reduced output chattering, the above two The application of this kind of controller to the synchronous static compensator control system can realize the rapid stability of the voltage at the common coupling, reduce the voltage overshoot and enhance the robustness of the system.

Description

technical field [0001] The invention relates to an improved second-order sliding mode control method for a synchronous static compensator. Background technique [0002] Synchronous static compensator is a new type of reactive power compensation device with voltage type or current type three-phase bridge converter as the core. It has the functions of reactive power compensation, suppression of voltage flicker and three-phase unbalance, etc. Compared with the traditional static reactive power compensation device, it has many advantages such as wide operation range, compact structure, rapid reactive power compensation, and is not easy to occur resonance. It has become a flexible power system. Hot spots in the field of AC power transmission. [0003] Synchronous static compensator is a complex nonlinear strong coupling system, and the control system becomes the key to affect the operating characteristics of the synchronous static compensator. The inverse system method can perf...

AI Technical Summary

Problems solved by technology

The inverse system method can decouple the linearization of the original system, and introduce a PI controller to realize the decoupling of active current and reactive current. However, there are disadvantages of low control accuracy and poor anti-disturbance performance.

The sliding mode can realize the nonlinear control of the current and DC voltage of the synchronous static compensator. The traditional first-order sliding mode has the problems of control discontinuity and inherent chattering, which affects the control effect of the system.

Images