Study On The System Of On-line Monitoring And Diagnosis For Transformer

The stability of power supply system is guaranteed by the safety and reliabilityof power transformer. The faults of transformer can influence other equipments in thepower supply system, and also bring enormous economic losses. The on-linemonitoring of transformer condition is an effective way to find the latent fault timelyand prevent the fault occurs. Then some measures, like repair or change, can be takenimmediately, in order to avoid the serious results.Dissolved gas analysis (DGA) is widely used in transformer conditionmonitoring, because it can not be interference by external environment, and thetransformer can work normally during the DGA process. To analysis the gasesdissolved in the transformer oil, the qualitative and quantitative results are used todiagnosis the condition of transformer.The system of on-line monitoring and diagnosis for transformer that this paperstudied is based on the dissolved gas analysis. The whole system is constructed bythree modules, the DGA on-line monitoring device, fault diagnosis algorithm, and theonline monitoring and management system of transformer:（1）The on-line monitoring device for gases dissolved in insulation oil isconstituted by oil-gas separation section and gas detection section. After comparativeanalysis, oil-gas separation section is depending on dynamic headspace degassing,and gas detection section is depending on the photoacoustic spectroscopy technology.The experimental data show that this device has high precision and good stability.（2）Introduce some traditional diagnosis algorithms which are always using theratio calculation by two gas concentration to identify the fault of transformer. Andresearch a dynamic weighted fuzzy clustering algorithm. This method can avoid theerror diagnose which is caused by loss of code or boundary problem in traditionaldiagnosis algorithms.（3）At last, a power transformer on-line monitoring management system whichis using B/S framework has been designed. It is no longer need to install or update thesoftware complexity, and can obtain the real-time condition data by Internet. It alsocan diagnose the fault of transformer in operation on-line, and to confirm the information by visualized method.