互联电力系统联络线功率波动机理及其扰动概率分析

摘要

The daily statistics of valid disturbances recorded in the historical data of the wide-area measurement system (WAMS) can reflect the stability level of a power grid. The formulas of the small signal analysis including power disturbance on the grid is given firstly; then the relationship between damping ratio and response of the oscillation magnitude of the tie-line active power is analyzed; and the relationship of the oscillation probability and damping ratio is obtained. Finally, a case study based on 10-machine 39-bus power system verifies the validity of the expression of oscillation amplitude of tie-line active power and the relationship between the oscillation probability and damping ratio. These theoretical results can be used to guide the power operator to assess the damping level of the power grid based on the daily oscillations number recored by WAMS. This work is supported by National Natural Science Foundation of China (No. 51207063).%广域测量系统的历史数据中统计的电网每日发生有效扰动次数的突然变化能够反映系统的稳定水平的变化,因此研究并从理论上给出扰动概率和阻尼比的数学关系对分析和评估电网的稳定性具有重要意义.基于此,在分析了计及网络中功率扰动的小干扰计算的基础上,通过分析联络线对扰动的响应,推导得出了联络线功率波动幅值与阻尼比的解析关系.然后,基于扰动服从正态分布的假设给出扰动概率与阻尼比的关系式.最后以 10机39节点系统为例进行算例分析,验证了推导得出的联络线振荡幅值解析表达式的正确性和分析了联络线功率扰动概率与阻尼比的关系.研究结果可为广域测量系统历史统计数据的分析及电网稳定性评估提供理论参考.