基于差值计算法的系统分区惯量评估方法

随着新能源的大量接入，系统惯量下降且分布不均的特征日益明显，系统频率响应呈现时空分布特性。文中提出了一种基于差值计算法的系统分区惯量评估方法。首先，根据机组间频率响应特性相似程度对系统进行分区，并确定各区域的主导机组。然后，在分区和主导机组选取基础上，提出了一种差值计算方法，测量扰动发生后区域间联络线上功率和主导机组频率，对各区域惯量水平进行评估。该方法所需测量数据较少，只须在区域间联络线和主导机组上测量数据，能够实现惯量评估的在线应用。在PSASP中建立了IEEE 10机39节点系统，验证了所提方法在系统不同运行情况下的正确性，并分析了扰动数据时间段的选取对惯量评估正确性的影响。验证结果表明，所提方法适用于含大规模新能源电力系统惯量评估，具有较高的精度。

Assessment Method of System Partition Inertia Based on Differential Calculation Method

With the large-scale integration of renewable energy resources, the characteristics of decreasing and uneven distribution of the system inertia are becoming increasingly obvious. and the system frequency response is spatial and temporal distributed. An assessment method of system partition inertia based on differential calculation method is proposed. Firstly, the system is divided into several areas according to the similarity of frequency response characteristics and the dominant generator in each area is determined. Based on the partition and selection of dominate generators, a differential calculation method is proposed to assess the inertia level of each area using the interconnector power and the frequency of the dominant generators after disturbances. The proposed method requires only a few measurement data, which just needs to measure the data from regional interconnectors and dominate generators, and can be implemented by online estimation. The IEEE 10-machine 39-bus system is established in PSASP to verify the correctness of the proposed method in different operation conditions. The impact of the time period selection of disturbed data on inertia assessment is analyzed. The results show that the proposed method has high accuracy in inertia assessment of power system with the large-scale integration of renewable energy resources.