基于新能源出力比例的大规模系统惯量估计

Large-scale System Inertia Estimation Based on New Energy Output Ratio

在构建新型电力系统时,提高新能源出力比例,将降低系统惯量。为保证系统频率的安全稳定,需要根据新能源出力比例估计系统惯量,用以指导新能源装机规划及开机方式安排。梳理了常用惯量指标,选取了系统总动能作为描述系统惯量的估计指标。针对实际特定系统,根据典型量测数据给出了提高新能源出力比例后的惯量估计方法;针对没有量测数据的大规模新能源规划系统,用新能源出力比例来推断同步机的开机容量范围,综合考虑同步惯量和虚拟惯量,提出大规模系统的惯量评估关键参数及其统计方法,建立了系统惯量范围的估计模型。最后,基于某省级电网建立了不同新能源高出力比例模型,并对出力比例、惯量、频率之间的关系进行了分析研究,验证了有效性。

When constructing a new power system,increasing the ratio of new energy output will reduce the system inertia.To ensure the safety and stability of the system frequency,the system inertia needs to be estimated based on the ratio of new energy output to guide the new energy installation planning and the Boot mode arrangement.This paper sorts out the commonly used inertia indicators,and selects the total kinetic energy of the system as the estimated indicator to describe the system inertia.According to the actual specific system and the typical measurement data,the method of inertia estimation after the increase of the new energy output ratio is given.For the large-scale new energy planning system without measurement data,the new energy output ratio is used to infer the start-up capacity of the synchronous machine.Comprehensively considering the synchronous inertia and the virtual inertia,the key parameters and the statistical methods are put forward for the inertia evaluation of the large-scale systems,and an estimation model of system inertia range is established.Finally,based on a provincial power grid,a high-output ratio model of different new energy sources is established,and the relationships between the output ratio,the inertia,and the frequency are analyzed and studied,verifying the validity of the proposed method.