基于增广递推最小二乘的电网等效惯量在线估计方法

An Online Estimation Method of Power Grid Equivalent Inertia Based on Augmented Recursive Least Squares

针对高比例非同步电源接入下电网等效惯量水平感知难题,提出一种基于量测数据的电网等效惯量在线估计方法。首先,利用发电机有功功率变化及节点频率数据,采用带外部输入的自回归滑动平均(auto regression and moving average model with exogenous input,ARMAX)模型对各区域/整个电网有功-频率动态变化进行建模。进而,基于增广递推最小二乘(recursive extended least squares,RELS)算法实现自回归滑动平均模型中未知参数的求解,辨识得到系统或区域惯性常数的估算值。此外,考虑区域间交流联络线提供的惯量支撑,对出现不平衡功率扰动后的区域惯量通过联络线耦合现象进行估计和分析。最后,基于某省级电网实际数据进行仿真测试,验证了所提方法的正确性和有效性,并对互联区域联络线提供的惯量支撑进行了分析。

In this paper,an online estimation method of equivalent inertia based on measurement data is proposed to solve the problem of equivalent inertia level perception under high proportion of non-synchronous power supply.Firstly,using the data of generator active power change and node frequency,auto regression and moving average model with exogenous input(ARMAX)model models active power-frequency dynamic changes in each region/whole power grid.Furthermore,the recursive extended least squares(RELS)algorithm is used to solve the unknown parameters in the ARMAX model,and the estimated values of the inertia constant of the system or region are identified.In addition,considering the inertia support provided by the interregional contact line,the coupling phenomenon of regional inertia through the contact line after unbalanced power disturbance is estimated and analyzed.Finally,based on the actual data of a provincial power grid,the correctness and effectiveness of the proposed method are verified by simulation tests,and the inertia support provided by the interconnecting regional lines is analyzed.