Design And Development Of State Parameter Detection System For Oil-immersed Distribution Transformers

Oil-immersed distribution transformer is an indispensable equipment in the power system.The detection of its state parameters to achieve fault prediction and rapid diagnosis is a trend in the smart grid environment.Aiming at the problems of oil-immersed distribution transformers without detection system and high cost of detection system,the design and development of the state parameter detection system for oil-immersed distribution transformers is carried out.Based on the working principle of oil-immersed transformer and the change of state parameters and combined with the research status,the test parameters,functions and performance indexes of the system are clarified,and the overall design scheme is proposed.The realization of each module function in the electromagnetic interference environment is studied.Considering the serious electromagnetic interference phenomenon,the system electromagnetic compatibility design is carried out.On this basis,the state parameter detection system has built a 17-channel parameter testing subsystem of transformer oil temperature,oil pressure,oil liquid level,winding temperature,vibration,three-phase voltage on high voltage side and low voltage side,three-phase current on high voltage side and low voltage side.The work of sensor selection and conditioning circuit design for each subsystem is carried out;Based on the control system with the STM32F103ZET6 as the core,the state parameter detection system realizes the functions of collecting data,LCD display and Ethernet transmission;The host computer written by LabVIEW includes data receiving and storage software and data processing and analysis software,which realizes the functions of receiving,storing,playing back,processing,analyzing and outputting the status report of the transformer.It provides data support for the identification of transformer status and the analysis of faults.The performance test and measurement uncertainty evaluation of the system are carried out.The results show that the performance and measurement uncertainty of the state parameter detection system meet the expected design requirements.