电工技术学报2025，Vol.40Issue(13)：4085-4099,15.DOI:10.19595/j.cnki.1000-6753.tces.241007
单相变压器内部短路多尺度故障分析模型构建方法
Construction Method of Multi-Scale Fault Analysis Model for Single-Phase Transformer with Internal Short Circuit
摘要
Abstract
Internal short circuit is one of the most serious faults in transformers,which can lead to a rapid increase in fault energy in a short period of time and easily cause high-energy discharge and explosion inside the equipment.However,there are many potential combinations of internal short circuit conditions in transformers.The analysis method of field-circuit coupling commonly used by transformer manufacturing enterprises has the problems of excessive time and resource consumption.And it is difficult to model jointly with the external power grid.Existing circuit models face difficulties in multi-scale coupling characterization and parameter calculation of windings. This article focused on the urgent need for transformer short circuit fault analysis.A construction method of multi-scale fault analysis model for single-phase transformer with internal short circuit was proposed.Firstly,based on the multi-scale characteristics of transformer windings and internal short circuit faults,the transformer windings were virtually divided into several sub-windings using axial segmentation.By parametrically scanning the finite element model of the transformer,the self-mutual inductance matrix and resistance matrix of sub-windings was calculated.Secondly,an calculation method was proposed to transform the self-mutual inductance matrix into the coupled leakage inductance matrix,which could effectively characterize the leakage magnetic characteristics between sub-windings.This parameter calculation method could be carried without port short circuit tests,which solved the problem of parameter calculation for existing multi-winding transformer models.Finally,a multi-scale circuit model for transformers was established based on the coupled leakage inductance matrix.By connecting the terminals of each sub-winding based on the electromagnetic connection relationship and the physical process of internal short circuit,transformer fault analysis models for different internal short circuit conditions could be obtained.The problems of low efficiency and poor circuit adaptability in the fault analysis model based on field-circuit coupling were solved. Furthermore,a disk-scale circuit model of an 80 MV·A single-phase transformer was constructed.A comparative simulation was conducted with the finite element model.The results indicated that the errors of the short-circuit impedance and the peak value of the port current at rated operating condition were almost zero.And the simulation time was reduced by about 99.98％.After single inter-turn short circuit faults,the errors of the first peak values of the port currents and short-circuit currents did not exceed 2.5％.The simulation efficiency was improved while ensuring simulation accuracy.Then,based on a certain engineering accident,a developmental inter-turn short circuit analogy simulation analysis was carried out.The errors of the first peak values of the port currents and short-circuit currents after the fault,as well as the local peak values during the fault development process,did not exceed 5.5％.And the duration of the second harmonic percentage of fault differential current accounting for more than 15％of the circuit model was calculated to be 49 ms.It was consistent with the finite element model calculation results.The existing method was 14ms.Therefore,the proposed construction method of multi-scale fault analysis model for single-phase transformer with internal short circuit can accurately simulate the transient characteristics of transformers with internal short circuit under multiple scales and operating conditions.This method provides a basic model for research on equipment accident analysis,traceability,and fault defense.关键词
单相变压器/多尺度电路模型/内部短路/耦合漏感矩阵/有限元法Key words
Single-phase transformer/multi-scale circuit model/internal short circuit/coupled leakage inductance matrix/finite element method分类
信息技术与安全科学引用本文复制引用
杨鸣,赵小涵,司马文霞,李刚,李坤,倪鹤立..单相变压器内部短路多尺度故障分析模型构建方法[J].电工技术学报,2025,40(13):4085-4099,15.基金项目
国家电网公司科技项目资助(5108-202218280A-2-365-XG). （5108-202218280A-2-365-XG）
