考虑AGC采样保持特性的时滞电力系统频率稳定性分析  

Frequency Stability Analysis of Time-delay Power Systems Considering Sampling and Holding Characteristics of AGC

作　　者：陈亦平[1] 皮杰明 李崇涛 赵利刚 唐王倩云 方必武 李永亮 CHEN Yiping;PI Jieming;LI Chongtao;ZHAO Ligang;TANG Wangqianyun;FANG Biwu;LI Yongliang(Power Dispatching and Control Center,China Southern Power Grid,Guangzhou 510663,Guangdong Province,China;Electric Power Research Institute,China Southern Power Grid,Guangzhou 510663,Guangdong Province,China)

机构地区：[1]中国南方电网电力调度控制中心,广东省广州市510663 [2]中国南方电网科学研究院有限责任公司,广东省广州市510663

出　　处：《电网技术》2023年第8期3335-3342,共8页Power System Technology

基　　金：中国南方电网公司重点科技项目(ZDKJXM20200046)。

摘　　要：电力系统的自动发电控制(automaticgeneration control,AGC)是典型的采样控制系统,具有调节周期长、通信延迟显著的特点。基于单区域负荷频率控制(load frequency control,LFC)系统,该文提出一种适用于考虑AGC采样保持特性的时滞电力系统频率稳定性分析方法。首先利用零阶保持器建立考虑AGC采样保持特性的LFC连续–采样混合系统模型;然后利用切比雪夫离散化方法处理模型中的时滞变量,基于函数空间方法建立等值的离散化系统;随后提出基于离散化系统特征值的稳定性判据。为说明考虑AGC采样保持特性的必要性,该文还建立了忽略AGC采样保持特性和用零阶保持器连续传递函数建模的LFC连续系统模型,通过比较不同模型的时滞稳定裕度说明不同建模方法的保守冒进程度。最后通过时滞稳定裕度上的时频域仿真分析验证所提稳定性分析方法的准确性。Automatic Generation Control(AGC)with long control period and inevitable time delays is a sampled-data control system.This paper proposes an eigenvalue-based frequency stability analysis for time-delay power systems adapting to the sampled-data AGC based on a single-area load frequency control(LFC)system.Firstly,the hybrid continuous and sampled-data LFC model is established by modeling the sampled-data AGC as a proportional-integral(PI)controller with zero-order holder.Then,the Chebyshev discretization is applied to deal with retarded variables in the system model,and the equivalent discrete system is obtained based on a function space approach.In this way,the eigenvalue-based stability criterion is developed.Besides,for illustrating the necessity of the sampled-data characteristic of the AGC,another two kinds of continuous-time LFC models are also established for verifying their conservativeness with the delay margin comparison.Finally,time-domain simulations and frequency-domain analyses on the delay margins are carried out,showing the accuracy of the proposed eigenvalue-based stability analysis.

关 键 词：自动发电控制 负荷频率控制 采样保持特性 时滞电力系统 频率稳定性分析 

分 类 号：TM721[电气工程—电力系统及自动化]