摘要
电力系统惯量大小是衡量系统频率稳定性的重要指标之一。由于新能源机组缺乏常规同步发电机组类似的惯量响应能力,其大规模并网将会降低系统的等效惯量,易引发频率安全事故。在构建以新能源为主体的新型电力系统的过程中,有效监控电网等效惯量大小是预防频率失稳风险的重要技术手段。基于此,提出了一种采用功率谱密度分析的电力系统等效惯量评估方法。该方法理论推导出了随机噪声扰动情况下系统等效惯量大小与频率波动量功率谱密度之间的数学关联关系;通过量测系统频率波动情况,求取其功率谱密度,根据系统等效惯量与频率波动量功率谱密度的数学关系,采用非线性最小二乘拟合求取系统的等效惯量大小。单区域系统、含新能源的四机两区系统以及某实际电网的仿真结果表明:所提方法能够准确评估系统的等效惯量大小,具有良好的工程实用性。
The inertia of a power system is one of the important indicators to measure the frequency stability.The renewable energy units lack the inertia response capability similar to conventional synchronous generator units,thus the large-scale grid connection of renewable energy will reduce the equivalent inertia of the power grid,and the low inertia of the power grid will easily cause frequency safety accidents.In the process of constructing a novel power system with renewable energy as the main body,it is an important technical means to effectively evaluate the equivalent inertia of power grid.It will help to prevent the risk of frequency instability.Thereby,this paper proposes a power system equivalent inertia evaluation method by power spectral density analysis.This method theoretically derives the mathematical correlation between the equivalent inertia of the system and the power spectrum density of frequency fluctuations under the random noise disturbance.Then the frequency fluctuations of the power grid is measured and its power spectrum density is obtained.According to the mathematical relationship between the equivalent inertia of the system and the power spectral density of frequency fluctuations,nonlinear least squares fitting is used to obtain the equivalent inertia of the system.The simulation results of a single-area system,four-machine two-area system and a real power grid show that the proposed method can be adopted to accurately evaluate the equivalent inertia of the system and has good engineering practicability.
作者
刘巨
赵红生
李梦颖
杜治
杨东俊
姚伟
LIU Ju;ZHAO Hongsheng;LI Mengying;DU Zhi;YANG Dongjun;YAO Wei(State Grid Hubei Electric Power Company Limited Economic Research Institute,Wuhan 430074,China;State Grid Wuhan Electric Power Supply Company,Wuhan 430074,China;State Key Laboratory of Advanced Electromagnetic Engineering and Technology,School of Electrical and Electronic Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2022年第1期178-188,共11页
High Voltage Engineering
基金
国网湖北省电力有限公司科学技术项目(521538210001)。
关键词
惯量
功率谱
非线性最小二乘
新能源
频率波动
新型电力系统
inertia
power spectral density
nonlinear least squares
renewable energy
frequency
novel power system
