Design And Implementation Of Online Monitoring Terminal For Low Voltage Power Grid

The rapid development of industrial technology and the continuous improvement of the level of technology have promoted the continuous growth of power users' power load and the diversity of power equipment,making the power sector pay more attention to power safety and power supply reliability.The safety and reliability of power systems are directly affected by the low-voltage power grid.How to achieve safe and reliable operation of low-voltage power grids has become the focus of the power sector.Based on the actual demand of low-voltage power grid condition monitoring,this thesis studies the design of low-voltage power grid online monitoring terminal for the low-voltage power grid condition monitoring system of scientific research projects.A set of real-time monitoring terminal equipment was developed,focusing on hardware design and software programming.The real-time monitoring terminal device is an integral part of the online monitoring terminal of the low-voltage power grid,and is arranged in the power distribution room to realize real-time monitoring and transmission of various parameters of the lowvoltage power grid user-side power distribution system,including three-phase voltage and current.The real-time monitoring terminal equipment adopts the STM32F103VCT6 enhanced 32-bit chip with Cortex-M3 as the core,and uses the STM32's own ADC to perform multi-channel synchronous analog-to-digital conversion on the input signal to realize the acquisition and processing of the signal to be tested.The data is transmitted between the acquisition unit and the main control unit via the RS-485 bus,and the communication protocol is customized and equipped with a 10-inch display touch screen for data display.In the process of developing real-time monitoring terminal equipment,according to the user's needs,a set of user side pre-checks equipment was developed at the same time,and the hardware design and software program were written for the pre-checks equipment.The user side pre-checks equipment is mainly applied to the newly-built or modified user power distribution system.After the installation of the user-side power equipment is completed,and before the low-voltage main power supply is energized,the user power supply line is pre-checked in advance,including short circuit,Pre-test for leakage and other conditions.Know the line faults in advance to further improve the safety of power consumption.The user side pre-checking device also uses the STM32 series processor as the main controller,and is equipped with a 10-inch display touch screen for pre-check result display.Through the design of real-time monitoring terminal equipment and user-side prechecks equipment software and hardware,and after repeated debugging,the expected design goals are achieved.The user side pre-checking device can perform pre-detection on the user side line.Real-time monitoring terminal equipment can realize online monitoring of lowvoltage power grid operation,and upload and display data in real time and accurately.The operation and maintenance personnel can view the operation status of the low-voltage power grid through the man-machine interface.The human-machine interface also provides data support for the power supply department to understand the operating conditions of the lowvoltage power grid.