非运行状态电容式电压互感器绝缘体系生物降解分析

Analysis of the Impact of Microbial Degradation on the Insulation System of the Offline Capacitive Voltage Transformer

探究非运行状态电容式电压互感器(CVT)油-纸绝缘体系中CH_4、H_2和CO_2等气体含量增高的原因,对提高CVT运行安全很有必要。采取自然污染、人工接种及高温杀菌方式对CVT油-纸绝缘体系进行微生物生长试验,用气相色谱仪、微水仪等仪器测定生物降解绝缘油-纸的产物及含量,并采用生物学鉴定微生物种属,分析油-纸绝缘体系生物降解特性。试验结果表明:CVT油-纸绝缘体系在微生物降解作用下产生了H_2O、酸、CH_4、H_2和CO_2等,其与非运行状态下CVT内绝缘油中气体组分相同;各组分气体含量在增加过程中出现一减小的拐点;显微镜观察和生物学鉴定出4种球状厌氧微生物。结合生物降解产物及变化趋势和微生物种属分析,CVT油-纸绝缘体系生物降解分为2个阶段,即多种微生物降解和厌氧微生物沼气发酵阶段,CH_4、H_2和CO_2等气体是生物降解的特征气体。

To improve the safety of the capacitor voltage transformer(CVT)operation,it is necessary to study why the amount of the gas contents such as CH4,H2 and CO2 in the oil-paper insulation system of the offline CVT increases.The microorganism growing experiment in the oil-paper insulation system of the CVT is conducted by using the methods of natural inoculation,artificial inoculation and high-temperature sterilization.The microbial degradation products and their amounts are determined with the gas chromatograph,the micro water detector and some other equipments.The microorganism species are identified with the molecular biological method,and the degradation characteristics of the insulation system are analyzed.The results show that the H2O,acids,CH4,H2,and CO2 are produced during the microbial degradation in the oil-paper insulation system and the components are the same as those found in in the insulating oil of the offline CVT Also,an inflection point of decrease is observed in the gas component increasing process.Four spherical anaerobic microorganism species are detected by microscopic observation and biological identification.It is concluded that the bio-degradation of the oil-paper insulation system of the CVT has two stages,the multimicrobial degradation and anaerobic methane fermentation.The CH4,H2 and CO2 are the characteristic gas produced from the degradation.