样本不平衡情况下的电力系统暂态稳定集成评估方法  

Integrated Assessment Method for Transient Stability of Power System Under Sample Imbalance

作　　者：李嘉敏 杨红英 闫莉萍[1] 刘道伟 李宗翰 夏元清[1] 赵岩 LI Jiamin;YANG Hongying;YAN Liping;LIU Daowei;LI Zonghan;XIA Yuanqing;ZHAO Yan(School of Automation,Beijing Institute of Technology,Beijing 100081,China;China Electric Power Research Institute,Beijing 100192,China;Electric Power Research Institute of State Grid Shandong Electric Power Company,Jinan 250003,China)

机构地区：[1]北京理工大学自动化学院,北京市100081 [2]中国电力科学研究院有限公司,北京市100192 [3]国网山东省电力公司电力科学研究院,山东省济南市250003

出　　处：《电力系统自动化》2021年第10期34-41,共8页Automation of Electric Power Systems

基　　金：国家电网公司总部科技项目(电力系统广域协调运行控制技术,5100-201955448A-0-0-00)。

摘　　要：为了在电力系统发生暂态故障后能够快速、准确地对系统稳定性进行判断,并解决样本不平衡对模型造成的倾向性问题,提出了一种基于改进损失函数的电力系统暂态稳定集成评估方法。首先,基于故障清除后的短时量测数据,设计了一种结合1维、2维单通道和2维多通道卷积神经网络的集成模型,实现了端对端的抽象特征提取和暂态稳定分类。其次,改进了模型训练过程中的损失函数,加强了对失稳样本的拟合程度,增加了错分样本的权重,从而提高了全局准确率,并减少了失稳样本漏报现象的发生。此外,文中还分析了集成模型输出的判定阈值对失稳样本召回率的影响。最后,IEEE 39节点系统和IEEE 145节点系统的仿真结果验证了所提方法的有效性。In order to quickly and accurately evaluate the stability of the power system after a transient fault occurs in the power system, and to solve the bias problem of the model caused by sample imbalance, an integrated transient stability assessment method for power systems based on the improved loss function is proposed. Firstly, based on the short-term measurement data after the fault clearing, a new integrated model that combines one-dimensional, two-dimensional single-channel and twodimensional multi-channel convolutional neural networks is designed to realize the end-to-end abstract feature extraction and transient stability classification. Secondly, the loss function in the model training process is improved to enhance the fitting degree of unstable samples for increasing the weights of the misclassification samples. Thus, the global accuracy is improved, and the missing alarm rate of unstable samples is reduced. Moreover, the influence of the output threshold of the integrated model on the recall rate of instable samples is analyzed in this paper. Finally, the simulation results of IEEE 39-bus system and IEEE 145-bus system verify the effectiveness of the proposed algorithm.

关 键 词：卷积神经网络 集成模型 暂态稳定评估 样本不平衡 电力系统 

分 类 号：TM712[电气工程—电力系统及自动化]