Nonlinear Modeling and Control of a VSC-HVDC Transmission Systems

This paper presents a new modeling and control strategy of VSC-HVDC transmission system in order to improve system damping oscillations, and enhancing transient and voltage stability. This control strategy is based on a linear and bilinear state space deviation models. The structure of the control method is designed in order to minimize the number of the control loops (inner and outer control loops) in the classical strategy to one control loop for each output. These control loops are active power or DC voltage for the first output, and the reactive power for the other output. Simulations for VSC-HVDC transmission system model show the validity of the derived models and the effectiveness of the control strategies.