Parameters optimization of VSC-HVDC control system based on simplex algorithm

The performance of VSC-HVDC system depends on the parameters of control system, and usually PI controllers have been used to adjust system to fulfill desired objectives. However, the optimization methods for PI controllers' parameters of VSC-HVDC system are very few up to now. A control strategy based on direct analytic expression for VSC-HVDC is presented and the corresponding control system is designed. Simplex algorithm and system objective function are adopted to optimize the PI parameters for single- and multi-objective VSC-HVDC system on the basis of the control strategy. Simulation results in PSCAD/EMTDC software testify the performance of VSC-HVDC control system with optimized PI parameters and show that the controllers with the optimized PI parameters can effectively control VSC-HVDC system. Advantages of the control system with optimized parameters, such as precise control, quickly responding time and strong robustness have been testified by step response.