Design And Implementation Of The Transformer Bias Current Monitoring System Based On Cloud Server

Geomagnetic disturbance and mon opolar operation of DC transmission system are both inductors of transformer biasing current.The biasing current will generate the half wave saturation and a lot of harmonics,which will not only increase the reactive power of the transformer but also cause the malfunction of relay protection device and endanger the safety of the power grid.The real-time monitoring of the biasing current at the neutral point of the transformer can not only observe the state of the transformer,but also guide the personnel to take appropriate measures to defend current bias.Therefore,the theory and technology of transformer biasing current monitoring are of great significance to the safe operation of power grid and transformers.The main contents and results of this article are as follows:Firstly,the generation mechanism and the flow path of biasing current of transformers under different inducements are summarized.Furthermore,the frequency and amplitude characteristics of the biasing current of the transformer under different inducements are obtained through calculation of practical cases and analysis of relevant test results,which provides a basis for the design of the real-time monitoring terminal of the biasing current.Secondly,according to remote communication theory and technology,a real-time monitoring system scheme for transformer biasing current based on cloud server is proposed.Based on the functional requirements of the data collection system,the hardware and software design of the data collection terminal was carried out.The key components are analyzed and selected according to the biasing current characteristics,and the signal conditioning circuit is analyzed,designed,calculated,and priori simulated.With the high-performance embedded microprocessor STM32F103 as the core,the hardware circuit design and software program design of the data acquisition terminal of the monitoring system are completed.The design process optimizes the layout,wiring,and electromagnetic compatibility based on the application requirements of the project.Thirdly,the monitoring platform is designed based on cloud server.The main body of the monitoring platform adopts B/S architecture,and uses the mode of separating the front end and back end to complete the configuration and framework of the system development platform environment,and realizes the functions such as receiving remote acquisition terminal data,real-time sharing and publishing of monitoring data,data storage and invocation,and historical data query.Finally,a test platform for transformer biasing current monitoring system was built,and performance tests are conducted on the data collection terminal and the cloud server-based monitoring platform,and the data collection terminal and monitoring platform are jointly debugged.Furthermore,relevant field tests are carried out at a 330kV substation to verify the function and performance of the monitoring system,laying a foundation for further engineering applications.