A novel control strategy for three-phase UPS based on B-spline Network

This paper is concerned with the control of three-phase Uninterruptible Power Supply (UPS) systems based on a B-spline Network (BSN). A UPS must be able to maintain regulated output voltage in the face of all line/load disturbances. To achieve this, the control system of a UPS must have a fast transient response and a low steady-state error. Fast controllers cannot always maintain the required steady-state accuracy. Therefore, in this paper, a hybrid control solution is proposed. In the proposed method, a fast yet simple controller based on deadbeat (DB) control law is used to achieve the fast transient response required for UPS output voltage control. A B-spline based controller is added to the deadbeat controller to improve steady-state performance of the UPS system. This results in distortion-free output voltage along with a fast error convergence. The system modeling and controller design for the proposed structure are presented in this paper. Simulations results are shown for verification of the theoretical analysis.