基于扫频法的直流附加控制器设计

将复转矩系数法的概念进行了推广，并应用到直流附加阻尼控制器的设计中.通过对交直流系统进行低频范围内的频率扫描，可以得到满足系统稳定性要求的控制器频域特性，并以此为约束条件确定控制器的结构和参数.采用该方法获得的各系数曲线结果直观，特别适合分析系统运行参数的变化对控制器效果的影响，有利于设计出能同时满足多种运行方式的鲁棒控制器.算例分析结果表明，当系统运行点发生较大范围变化时，所设计的附加控制器仍能有效阻尼两区域四机系统中的低频振荡.

Design of HVDC Supplementary Controller Based on Frequency Scanning Method

The concept of complex torque coefficient was extended to the design of HVDC supplementary controller.By scanning the AC/DC system in low frequency band,the frequency domain characteristics of controller were derived,which should satisfy the desired performance and stabilize the system.Setting the frequency domain characteristics as constraint conditions,the structure and the parameters of the controller can be determined.The index curves obtained are visible and intuitional,easy to analyze the effects of system parameter variations on the controller performance,and helpful to gain the robust controller.In the two-area four-machine system of the case study,the results show that under various operation conditions,the supplementary controller can damp out the low frequency oscillations.