Study on Parameter Optimization of HVDC PI Controllers

A systemized optimization method for PI parameters of HVDC controller is proposed. First, according to the Bode plot the ranges of PI parameters satisfying the requirement of system stability are found; then these parameter ranges are divided by a certain step length to obtain finite pairs of PI parameters to compose a sample set for PI parameters optimization. Next, the step response of controller is simulated for each pair of the sample parameters, and the values of objective function are calculated with ITAE (integral of time multiplied by the absolute value of error) performance index. Finally, the sample parameters corresponding to minimum value of ITAE objective function is taken as optimal PI parameters. The found optimal PI parameters can be approximately regarded as global optimal in real projects. According to above-mentioned method the PI controller for HVDC transmission project from Gezhouba to Nanqiao is designed and the effectiveness of this controller is verified by simulation.