基于振动偏离及加权熵的多次短路冲击下变压器绕组机械形变辨识  

Mechanical Deformation Identification of Transformer Winding under Multiple Short-Circuit Impacts Based on Vibration Deviation and Weighted Entropy

作　　者：律方成[1,2] 汪鑫宇 王平 高树国[3] 耿江海 LüFangcheng;Wang Xinyu;Wang Ping;Gao Shuguo;Geng Jianghai(Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defense North China Electric Power University,Baoding 071003 China;State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University,Beijing 102206 China;State Grid Hebei Electric Power Research Institute,Shijiazhuang 050021 China)

机构地区：[1]华北电力大学河北省输变电设备安全防御重点实验室,保定071003 [2]新能源电力系统国家重点实验室(华北电力大学),北京102206 [3]国网河北省电力有限公司电力科学研究院,石家庄050021

出　　处：《电工技术学报》2023年第11期3022-3032,共11页Transactions of China Electrotechnical Society

基　　金：河北省自然科学基金资助项目(E2021521004)。

摘　　要：为了研究变压器绕组在多次短路冲击的累积效应影响下逐步机械形变问题,开展了多次110 kV真型变压器短路试验,采集了振动暂态信号和轴向压力稳态值,分析了历次短路过程中振动偏离和加权时频谱熵的变化趋势。结果表明,累积效应导致的绕组机械劣化会使振动加速度偏离未形变状态基准值,且加权时频谱熵增大;结合材料力学及绕组轴向振动动力学模型,推导出当振动加速度呈正偏离时,短路侧绕组形变形式为轴向外凸膨胀,反之为轴向内凹压缩的关联规律。最后提出并验证了一种基于振动偏差模值及加权时频谱熵联合分析的绕组形变辨识方法,该方法较传统阻抗法能够在绕组早期微小形变时更早发现机械稳定性下降。研究结果对变压器绕组形变预警具有一定指导意义。The accumulative effect of transformer windings under multiple short-circuit impulse will eventually lead to sudden instability failure,so it is essential to study the mechanical deformation of windings under multiple short-circuit.Firstly,the multiple short-circuit tests under various working conditions on an 110 kV full-scale transformer were carried out,and the transient vibration acceleration signals during the short-circuit process and the steady-state values of the axial pressure of the windings before and after the multiple short-circuit were collected,the time-frequency characteristics of which were analyzed.According to the linear relationship between the vibration acceleration and the square of the current,the deviation trend between the measured value and the reference value is obtained,and the time domain characteristic of the vibration deviation is proposed.Then,combined with the winding axial vibration dynamics model,the relation between axial pressure,vibration deviation and deformation type is determined.Under HV-MV B-phase multiple short-circuit tests,the effective value of the vibration acceleration gradually produced a positive deviation.In the last test,the deviation value was^(2)1.5 m/s^(2),and the corresponding axial pressure was reduced from 3.15 t to 2.77 t.Similarly,under MV-LV A-phase multiple short-circuit tests,the vibration acceleration first produced a positive deviation of 2.37 m/s^(2) in the second test,and then gradually decreased.In the last test,it showed a negative deviation of-3.43 m/s^(2),and the corresponding axial pressure decreased from 4.29 t to 4.17 t and then increased to 4.43 t.According to the positive or negative deviation of the vibration acceleration under multiple-short circuit,the axial deformation type identification of the winding can be realized.When the vibration acceleration presents a positive deviation,the axial pressure decreases.The deformation form of the winding on the short circuit side is the outwards expansion of the end shaft.When the vibration acc

关 键 词：变压器绕组 累积效应 短路冲击试验 时频特征分析 形变辨识 

分 类 号：TM407[电气工程—电器]