直流输电比例-积分控制器的参数优化

提出了用于直流控制器比例一积分(proportional plus integral,PI)参数寻优的一种系统化方法。首先根据Bode图求出满足系统稳定性要求的PI参数范围;再对该参数范围按一定步长进行划分,得到有限组PI参数以构成PI参数寻优的样本集;对应每一个样本参数仿真计算控制器的阶跃响应, 并按时间乘绝对误差积分(integral of time multiplied by the absolute value of error,ITAE)准则计算目标函数值;取对应 ITAE目标函数值最小的样本参数为最优PI参数。找到的最优PI参数在工程上可近似认为是全局最优的。根据该方法设计了葛洲坝-南桥直流输电工程中的PI控制器,并通过仿真验证了其有效性。

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.