基于子空间辨识和遗传算法的多回直流协调阻尼控制器设计

Multiple-Loop HVDC Coordination Damping Controller Based on Subspace Identification and Genetic Algorithm

提出了一种多回直流协调阻尼控制器的设计方法,用子空间辨识法对系统降阶建模,用遗传算法进行参数寻优,并对时滞系统稳定性进行了评估。首先利用基于Prony分析的主模比指标计算法选择直流控制器的广域输入信号,通过仿真得到扰动下系统输入输出数据,基于数据对系统进行子空间辨识,得到系统开环状态空间方程。其次将控制器加入开环系统得到闭环系统状态空间方程,以多种运行方式下的系统最小阻尼比最大化为优化目标,针对闭环系统状态空间方程,用遗传算法对控制器参数进行协调优化。采用基于自由权矩阵的时滞稳定性判据,分析含有多回直流协调控制器的广域电力系统的时滞稳定性。最后以南方电网为例,对多回直流协调阻尼控制器进行仿真,仿真结果表明,通过该方法所得到的多回直流协调阻尼控制器能够较好地提高电网阻尼水平,并满足时滞系统稳定性的要求。

A design method was proposed for multi-loop DC coordination damping controller,which used subspace identification to reduced order modeling for system,used genetic algorithm for parameter optimization,and estimated the stability of time-delayed system. Firstly,the wide-area input signal of DC controller was selected by using dominate mode ratio index calculation method based on Prony analysis; the input and output data of the system under disturbance were obtained according to the simulation; and the open-loop state space equation was obtained by system subspace identification based on the data. Secondly,adding the controller in the open-loop system to get closed-loop system state space equation. Moreover,with maximizing the minimum damping ratio of the system under various operation modes as the optimization goal,genetic algorithm was used to coordinately optimize the controller parameter in closed-loop system state space equation. The stability criterion of system with time-delay based on free-weighting matrices was used to analyze the stability of system with time-delay for wide-area power system with multi-loop DC coordination controller. Finally,taking China Southern Power Grid as an example,the multi-loop DC coordination damping controller was simulated. The simulation results show that the multi-loop DC coordination damping controller obtained by this method can better improve the damping level of power gird,and meet the requirements of the stability of time-delayed system.