基于Pade近似的电力系统频率振荡模式延时轨迹分析  

Trajectory Analysis of Time Delay for Frequency Oscillation Mode of Power System Based on Pade Approximation

作　　者：陈锦洲 陈磊[1] 陈亦平[2] 闵勇[1] CHEN Jinzhou;CHEN Lei;CHEN Yiping;MIN Yong(State Key Laboratory of Control and Simulation of Power System and Generation Equipments,Tsinghua University,Beijing 100084,China;Power Dispatching and Control Center of China Southern Power Grid,Guangzhou 510623,China)

机构地区：[1]电力系统及发电设备控制和仿真国家重点实验室,清华大学,北京市100084 [2]中国南方电网电力调度控制中心,广东省广州市510623

出　　处：《电力系统自动化》2019年第14期120-125,共6页Automation of Electric Power Systems

基　　金：国家重点研发计划资助项目(2018YFB0904500);中国南方电网有限责任公司科技项目(ZDKJXM20160001)~~

摘　　要：实际电网中多次出现不同于传统低频振荡的频率振荡问题,和一次调频或自动发电控制强相关.包含一次调频、自动发电控制的电力系统调频过程是一个闭环的控制过程,是一个动态系统,面临着稳定性问题.在实际电网运行中,由调度自动发电控制指令到机组执行带来的延时对电力系统关键模态产生显著影响,从而改变闭环系统稳定性.基于一个三区域系统采用Pade近似方法将延时环节转化为状态空间表达式,选取合适的近似阶数,建立了考虑延时环节的电力系统线性化模型;并且通过特征值计算方法研究延时对频率振荡模式的影响规律,算例仿真结果有效验证了延时给系统带来的阻尼恶化、自动发电控制振荡模式发生周期性变化的结论.Several frequency oscillation incidents different from conventional low-frequency oscillations in actual power systems are strongly related with primary frequency regulation(PFR)or automatic generation control(AGC).The power system frequency regulation process including PFR and AGC is a closed-loop control process,which is a dynamic system and faced with stability problems.In actual power system,the time delay caused by dispatching AGC commands to the execution of unit has a significant impact on the critical modes of the power system,thus changing the stability of the closed-loop system.Based on a three-area system,Pade approximation method is used to convert the time delay process into a state space expression and a linear mode of power system considering time delay is built with an appropriate approximate order.The eigenvalue calculation method is adopted to study the influence of time delay on frequency oscillation modes.The results of the simulation validate the conclusion that time delay will reduce the damping of system and cause periodic changes in AGC oscillation mode.

关 键 词：频率振荡 Pade近似 延时 自动发电控制 频率振荡模式 

分 类 号：TM712[电气工程—电力系统及自动化]