The Study of Nonlinear DC Power Modulation Control in Multi-infeed HVDC Power Systems
A novel nonlinear DC power modulation control is proposed for multi-infeed HVDC in this paper. The idea is that the inter-area oscillations can be damped out by multi-infeed HVDC systems with COIs signals which means individual areas are driven to the stable equilibrium point. A three-area AC/DC power system is used as a sample to show the model derivation in COI coordinates. The back-stepping method is then applied to work out the nonlinear robust adaptive control law for DC power modulation in order to damp low frequency oscillations. Computer simulation results show that the proposed controller is superior to conventional DC power modulation controllers and can damp inter-area oscillations very well.