Feedback Linearization Based Nonlinear Control Strategy of VSC-HVDC

The model of Voltage Source Converter (VSC) based HVDC in the synchronous dq reference frame is presented in this paper. The model includes the DC link model and the VSC models. The feedback linearization principle for Multi-input Multi-output plants is analyzed. Based on the analysis, nonlinear decoupling control strategies for the two VSCs are proposed. For one VSC, the proposed nonlinear control strategy enables it to decouple DC voltage and reactive power control, and for the other one, the strategy guarantees the control of active power and that of reactive power independently. Simulation was conducted with MATLAB/Simulink software to verify the proposed control strategies. The simulation results prove that the nonlinear decoupling control strategies are able to provide good performance.