基于线性二次型最优控制理论的多频段高压直流附加阻尼控制器设计

摘要

针对交直流混合输电系统中存在的低频振荡和次同步振荡共存的问题,采用总体最小二乘-旋转不变技术对低频振荡和次同步振荡进行分析,获得系统的相关振荡频率、阻尼比以及系统降阶模型;再基于二次最优控制原理设计多频段高压直流附加控制器.利用直流功率快速调节的特点,对交流系统中因功率不平衡引起的振荡进行抑制;并引入极大极小值原理和改进粒子群算法来对控制器参数进行优化,最终达到同时抑制低频振荡和次同步振荡.最后在PSCAD/EMTDC中搭建某实际电网模型进行仿真验证;同时设计传统PI控制器进行分析对比.结果表明所设计的控制器具有更好的抑制效果和较强的鲁棒性.%For damping low frequency oscillations and sub-synchronous oscillation of actual AC-DC transmission system,the TLS-ESPRIT algorithm is used for analyzing the AC-DC transmission system in island mode to get relevant oscillation frequency,damping ratio and the order-reduced model of the system,and based on quadratic optimal control theory to design a additional controller for damping multi-band oscillations in HVDC power transmission system.And using DC power's quick adjustment is adopted to suppress oscillation caused by unbalanced power in AC system;and then introducing mini-max principle and improved particle swarm algorithm to optimize the controller parameters problem;and eventually achieving simultaneous suppression of low frequency oscillation and subsynchronous oscillation.Finally,an actual grid model is built in PSCAD / EMTDC for simulation verification,with traditional PI controllers for comparative analysis,the results show that the designed controller has better suppression effect and strong robustness.