A nonlinear control for enhancing HVDC light transmission system stability

The purpose of this paper is to study the mathematical model and its control strategy of HVDC Light transmission system in order to enhance system stability. In this paper, the steady state mathematical model for the HVDC Light system is developed and the decoupled relationship between the controlling variables is proposed. An appropriate controller utilizing nonlinear control for HVDC Light system is proposed to maintain the dc link voltage and control the active and reactive power. The control is not complex. Basic functions of HVDC Light system can be realized. What is further, better performances are obtained when compared with a traditional control. The digital simulation results show that the proposed nonlinear control is effective to damp system oscillations and enhance system stability.