模块化多电平换流器型多端高压直流输电控制参数优化方法

Aiming at the problem that the stability of modular multilevel converter based multi terminal high voltage direct current transmission system (MMC-MTDC) is affected by the interaction between the control systems of different converters, and inappropriate control parameters may reduce the stability margin of MMC-MTDC system, an optimization method of MMC-MTDC control parameters is proposed to improve the stability of the system. First, the small signal dynamic model of MMC-MTDC including MMC main circuit, control system, AC system and DC system was established. Second, the optimal design of control parameters with eigenvalue-based objective function was formulated, and a joint optimization algorithm based on parameter sensitivity analysis was proposed. In the process of optimization, backtracking line search (BLS) was applied to calculate the feasible optimization step of each iteration. Finally, the proposed control parameter optimization design method was applied in a three-terminal MMC-MTDC system. Stability assessment, time domain simulation and the comparison with the particle swarm optimization were performed to verify the effectiveness of the proposed parameter optimization design method.