Study of Nonlinear Control of SSSC Based on Differential Geometry Approach

Static series synchronous compensators (SSSC) can improve the power oscillation damping (POD) by controlling the power flow through the transmission line rapidly. In this paper, an improved nonlinear input-affine multivariable model for SSSC is established. Then the exact linearization method is used to realize the nonlinear control of SSSC. For avoiding solving the partial differential equation, the exact linearization methods which were proposed by some documents use the compound coordinate transform method, which is too intricate. This paper presents the direct method which can realize the exact linearization simply and conveniently. Finally, the paper applies optimal control theory to the linear model and designs the nonlinear optimal control approach of SSSC to improve power oscillation damping (POD). Simulation results validate the feasibility of the proposed modeling and control approach in damping out power system oscillations.