两起高压厂用变压器出口短路事故的诊断试验比对分析

Comparison and Analysis of Diagnosis Test for Two High Volt age Station Transformers After Outlet Short-circuit Accident

介绍了两台高压厂用变压器出口三相短路事故的概况和诊断性试验,包括介质损耗因素和电容量测试、油中溶解气体色谱分析、绕组直流电阻测试、短路阻抗和短路损耗试验、绕组频率响应分析等。根据两台变压器的历次试验数据,进行纵向、横向的同比分析和互比分析,以及使用比值分析法进行事故诊断和状态评价。结合两台变压器出口短路事故试验诊断比对分析结果,提出了对变压器开展零启升压下的空载试验、油中溶解气体色谱分析、计算产气速率、油中微量金属含量分析、低电压短路阻抗和短路损耗试验结合扫频短路阻抗检测的建议,以提高诊断比对和分析评价的正确性。

The general situation and diagnostic test items of two high voltage station transformers after outlet three-phase short circuit fault are introduced,then the dielectric loss factor and capacitance test,oil dissolved gas chromatographic analysis,winding re sistance test,short-circuit impedance and short-circuit loss test and winding frequency response analysis are described.According to the previous test data of the two trans formers,the longitudinal contrastive analysis and horizontal contrastive analysis are car ried out,and the fault diagnosis and state evaluation are carried out by the ratio analy sis method.Based on the comparison and analysis results of two transformers short-cir cuit accidents at the outlet,it is proposed to carry out no-load test at zero start voltage boost,combined with chromatographic analysis of dissolved gas in oil and calculation of gas production rate,analysis of trace metal content in oil,low voltage short-circuit impedance and short-circuit loss test combined with sweep frequency short-circuit impedance detection for transformers,so as to improve the correctness of diagnosis comparison and analysis evaluation.