Parameters optimization of VSC-MTDC control system to improve overall system stability

This paper introduces a multi-objective optimal method to coordinate the VSC-MTDC control system, which is aimed to simultaneously improve the dynamic performance of VSC-MTDC system and the rotor angle stability of the AC system. The coordinated control problem is formulated as an optimization problem where Particle Swarm Optimization (PSO) algorithm with the nonlinear time-domain-based objective function is employed to search the optimized parameters of VSC-MTdC controllers. The DC voltage is chosen as the key indicator that represents the VSC-MTDC system dynamic performance. So the multi-objective problem is mathematically represented by a composite set of objective functions comprising the DC voltage deviation of converters and the rotor angle deviation of generators. Time-domain simulations have been performed to assess the effectiveness of the proposed procedure.