Fault Monitoring And Diagnosis Of Hongyanhe Nuclear Power Plant 500KV Transformer

Power transformer plays an important role in the power system. With promoting development of industrial production, a lot of power transformers have applied to power system, and the booming nuclear power industry leads to growing demand for power transformer capacity in recent years. There will inevitably be problems in the long-term operation of transformer. Once the power transformer failure, the light is leading to the suspension of the transformer, the heavy is power transformer damage, and even a large area of power outages, resulting in industrial production stagnation and causing serious economic losses. Power transformer fault is usually caused by minor issue gradually developed into a big problem. Transformer shows some characteristics in early fault, and we can solve the related problems in the initial stage if we can find the fault characteristics in time. Thus, the power transformer can work properly and accidents and economic losses are avoided. Fault monitoring of power transformer mainly through the detection of transformer oil.This paper firstly analyzes the basic characteristics of transformer oil. The gas components in the transformer oil are the main characteristics of transformer fault condition. Then, it introduces the typical internal transformer fault, and analyzes the relationship between the internal transformer fault and transformer oil fault gases, also gives the principal gas and secondary gas components produced by different fault types of transformer. Then, transformer online monitoring technologies are introduced, including single gas, multiple gases and gases and moisture combined three types. The application of meteorological chromatography, sensor array, Fourier transform infrared spectroscopy and photoacoustic spectroscopy in the multiple gases on-line monitoring of transformer is summarized. Then the transformer fault diagnosis method based on three-ratio method is offered. By analyzing the oil sample obtained by artificial sampling using meteorological chromatograph, the transformer fault is judged using three-ratio method.On this basis, the specific functions of the transformer online monitoring system are analyzed, and the software and hardware design of the transformer online monitoring system based on TMS320F28335 controller is completed. Through experiments, measuring results of online monitoring device and Agilent 7890A are compared. Also, it is compared between the three-ratio code calculated by online monitoring device and the three-ratio code calculated artificially using the Agilent 7890A gas chromatograph measured data of each group. The experimental results check out the reliability of the measurement results of online monitoring device.