配电网侧小水电群整体惯量估计方法

Estimation Method of Overall Inertia of Small Hydropower Group in Distribution Network

配电网作为电力系统的重要部分,内含具有惯性响应的小水电群,但在传统的电网惯量和频率稳定评估中常忽略惯量贡献。同步相量测量单元(PMU)的出现,使获得扰动后数据估计配电网侧小水电群惯量成为现实。为实现对配电网侧小水电群的整体惯量估计,提出了一种基于有功—频率类噪声扰动信息的惯量估计方法,将配电网侧小水电群等效为一个整体,利用节点数据直接估计得到其整体等效惯量。算例结果表明,所提辨识方法能准确估计出单机惯量大小,并适用于节点下的配电网侧小水电群整体惯量辨识,从而减小由获取配电网侧内全部单机的数据进行整体惯量估计产生的误差和难度。

As an important part of the power systems,distribution network contains small hydropower group which have inertial response.However,its inertia contribution to the power grid was often overlooked in the traditional evaluation of power grid inertia and frequency stability.The appearance of Phasor Measurement Unit(PMU)made it possible to evaluate the inertia of small hydropower group in distribution network by using the disturbed data.To realize the estimation of the overall inertia on the distribution network,a continuous estimation method of inertia based on active-frequency data was proposed.The small hydropower group in distribution network was equivalent to a whole,and the node data were used to directly estimate the equivalent inertia of the entire small hydropower group.The example results show that the proposed identification method can accurately estimate the inertia,and can be applied to the identification of the overall inertia of the small hydropower group in distribution network under any node,thereby reducing the error and difficulty caused by obtaining the data of all single machines in the distribution network to estimate the overall inertia.