基于损失特征矩阵的CHB-BESS模块间接地故障诊断  

A fault diagnosis method for ground faults between CHB BESS modules based on loss characteristic matrix

作　　者：刘志豪 高逸群 张君[1] 凌志斌[1] 李旭光[1] LIU Zhihao;GAO Yiqun;ZHANG Jun;LING Zhibin;LI Xuguang(Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学,上海200240

出　　处：《储能科学与技术》2024年第3期850-857,共8页Energy Storage Science and Technology

基　　金：国家自然科学基金(52277221)。

摘　　要：模块间接地故障是H桥级联型电池储能系统(cascaded H bridge based battery energy storage system,CHB-BESS)的易发故障,快速诊断故障位置对减少故障损失至关重要。模块间接地故障的故障特征主要体现在零序电流上,会受到接地过渡电阻的影响。为实现接地过渡电阻不确定情况下,故障模块位置的快速准确鲁棒定位,本工作提出了一种基于损失特征矩阵的快速故障诊断方法。首先,本工作建立了零序等效电路模型;然后,将零序电流模型离散化;接着,提出基于损失特征矩阵的定位方法,该方法使用拓扑矩阵描述故障位置和过渡电阻的遍历信息,基于离散化模型来遍历计算零序电流,将计算结果与测量结果的偏差记录在损失特征矩阵中,通过偏差最优解确定故障位置;其次,本工作证实了故障定位问题作为最优化问题具有最优解唯一性,偏差最优解在接地过渡电阻不确定的情况下可获得准确的故障发生位置;最终,基于最优解唯一性提出了最优化计算的加速方法。实测表明,所提方法的平均定位误差仅为0.2个子模块,在接地过渡电阻较大范围不确定的情况下实现了准确定位,并且所提加速方法显著提高诊断速度。Battery energy storage systems based on cascaded H bridges are prone to grounding faults between modules,and reducing such fault losses requires rapid and accurate determination of the fault location.The electrical characteristics of the fault are related not only to the location of the fault but also to the ground transition resistance.To rapidly and accurately locate the fault module under conditions of uncertain grounding transition resistance,we propose a fast fault diagnostic method based on the loss characteristic matrix.First,a zero-sequence equivalent circuit model is established,and then the zero-sequence current model is discretized.Finally,a fault diagnostic method is developed based on the loss characteristic matrix.In this method,the topological matrix describes the traversal information of the fault location and the transition resistance.The zero-sequence current is calculated based on the discretized model,and the difference between the calculated and measured results is recorded in the loss characteristic matrix.This study further confirms that the fault location has a unique optimal solution,and given an uncertain ground transition resistance,the deviation optimal solution still accurately locates the fault.Based on convergence,this paper also proposes an acceleration method based on optimization calculations.The experimental results show that the average position given by the proposed method errs by only 0.2 submodules,which means that the fault position is accurately determined when the grounding transition resistance is highly uncertain.In addition,the diagnostic speed was significantly improved.

关 键 词：CHB-BESS 模块间接地故障 故障诊断 损失特征矩阵 最优化计算 

分 类 号：TM73[电气工程—电力系统及自动化]