Coordinated optimization of VSC-HVDC controller considering DC line

VSC-HVDC system, such as in offshore wind farms, will be widely used in the next few years. The controller parameters of both rectifier and inverter will have a great impact on both the system itself and the other parts of the transmission system due to the connection of DC transmission line. Usually, the controller parameters on each side are designed and tested separately. Therefore, the performance of the whole system can hardly achieve the best operation state. In this paper, a new method of coordinated optimization considering DC line is proposed. A united transfer function model is also established. Then, according to ITAE (integral of time multiplied by the absolute value of error) criterion, the parameters of both converters are optimized simultaneously. Simulation results verify the correctness and effectiveness of the proposed optimization method.