Gas Generation Characteristic And Diagnosis Method Of Electric-thermal Fault In Vegetable Oil Transformer

Transformer is the core equipment of voltage conversion,electric energy distribution and power transmission in power system.The operation of transformer is the key to ensure the safe,reliable and stable operation of power system.The vegetable oil transformer has good fire resistance,good environmental performance and excellent electrical performance.It meets the requirements of the requirements of environmental protection,energy saving and sustainable development.Research on vegetable oil transformer is the development direction of transformer research in the future.It is of great significance to prevent and reduce transformer fault rate and ensure the safe and reliable operation of power system.A comprehensive understanding of the gas production characteristics of vegetable oil transformers and the existing research status of vegetable oil fault diagnosis methods are the basis of this paper.On the premise of building a vegetable oil electro-thermal fault simulation experimental platform,electro-thermal fault simulation experiments for RAPO?vegetable oil transformer were conducted.The fault gas production characteristic of RAPO?vegetable oil was studied,a new criterion for fault diagnosis was proposed and the RAPO?vegetable oil fault diagnosis system was constructed.The innovative achievements mainly include:The simulation experiment platform for electro-thermal fault of vegetable oil was established.An experimental platform that can simulate the internal electro-thermal faults simulation of vegetable oil transformers was constructed.By reasonably arranging the positions of heating lamp,electrode and circulating system,the simulated environment is closer to the normal operation of the actual vegetable oil transformer and the electro-thermal environment under the fault conditions,so as to reduce errors and improve the reliability of the simulated data.The experimental platform lays a foundation for the simulation experiment of vegetable oil electro-thermal faults.Gas production characteristic of electric-thermal combined fault of RAPO?vegetable oil transformer was researched.A simulation experiment platform for electric-thermal fault of vegetable oil transformer was established to carry out thermal fault simulation experiment.The slight overheating fault(120?).low temperature thermal fault(200?),medium temperature thermal fault(500?),and high temperature thermal fault simulation(700?)were simulated under the conditions of electric stress(i.e.normal operating voltage without discharge).The gas production regulation of thermal faults in vegetable oil transformer and the influence of electrical stress on the gas production regulation of thermal faults were studied by gas chromatography detection.A simulation experiment platform for electric-thermal fault of vegetable oil transformer was established to carry out electrical fault simulation experiment.Partial discharge fault,spark discharge fault and breakdown discharge fault of vegetable oil under thermal stress(thermal stress,i.e.normal operating temperature of transformer)were simulated respectively.The gas production regulation of electrical fault in vegetable oil transformer and the influence of thermal stress on the gas production regulation of electrical fault were studied by gas chromatography detection.A simulation experiment platform for electric-thermal fault of vegetable oil transformer is established to carry out the electric-thermal fault simulation experiment.Under the condition closer to the actual operation and fault condition of transformer,partial discharge,spark discharge and breakdown discharge were carried out while simulating slight overheating fault(120?),low temperature thermal fault(200?),medium temperature thermal fault(500?)and high temperature fault(700?)were simulated simultaneously.Compared with the results of thermal faults and electrical faults simulation,the effects of electro-thermal faults on the gas production of vegetable oils were studied.A diagnostic method to characterize the electro-thermal fault of RAPO?vegetable oil was proposed.On the basis of the traditional ratio method,aiming at the problems of poor adaptability,single diagnosis range and too limited boundary,a new ratio criterion was introduced to construct a fault diagnosis method for vegetable oil transformers.The different temperature thermal faults in RAPO?vegetable oil transformer under the condition of electric stress,electrical faults of vegetable oil under thermal stress and electro-thermal faults can be diagnosed accurately and reliably by this method.The internal electro-thermal fault diagnosis system of vegetable oil transformer proposed in this paper is of great significance to promote the development of vegetable oil transformer towards large capacity and high voltage.