Research And Software Design Of Online Fault Diagnosis Method For Transfomer

With the modern large-scale use of electrical equipment, power systems is rapidly expanding the scale. Transformer as an important node of the power system , the reliability of their operation will directly impact on the power system stability and security. Analysis of gases dissolved in the insulative oil of transformer proved an effective means of detection and is widely used. As the amount of power transformer is rapid increasing, traditional artificial periodic testing is becoming increasingly unable to meet actual needs. On-line monitoring and remote monitoring has been put on the agenda.In this paper, transformer oil gas detection methods have been studied. On the basis of summarizin the research results internal and abroad, Combined with the need of the actual subject request, a program of transformer oil gas remote on-line monitoring is provided.Program is divided into three parts: the scene part, communication protocol and the host computer. The scen part including the choice of polymer membrane, gas separation method of choicing column, gas sensors and the choice of single-chip and so on. Using soluble polymer PTFE membrane permeability to gas mixture isolated from the transformer oil; Useing the principles of gas chromatography stationary phase through a two-phase chromatography column to separate the mixed gas into five kind of seperated gases: hydrogen, methane, acetylene, ethylene and ethane. The SnO2 semiconductor gas sensors detect concentrations of different gases and sent signal to Atmega32 which is the core of data-processing unit. Remote Communication was done bu using ModBus communication protocol between Data-processing unit and the host computer. The problem of serial communication's long packet of data is solved. Combined with SQL SERVER2000 database an VB6.0, the software and interface of host computer is designed. The functions of remote real-time data monitoring, system parameter settings, historical data records and fault diagnosis are archieved.Comparing with the method of tranditional experience or gas production rate, a improved third-ratio fault diagnosis method is provided. Comprehensive analysis the gas content, gas production rate and gas composition makes the diagnosis of fault type more accurate. With the Flexibility of On-line monitoring system, A variety of different occasions and demands for transformer monitoring are meeted...