Research On Current Monitoring Device Based On High Performance Magnetic Sensor

This paper analyzes the current status of the existing current monitoring equipment,and puts forward the research of current monitoring device based on high-performance magnetic sensor.This device can collect the current information of production equipment and pollution control equipment in real time.After information processing,the data is transmitted to the cloud server through NB-IoT.The data on the server can be used for real-time monitoring by relevant government departments,so as to provide suggestions and feedback for the formulation of environmental protection policies and realize the control of pollution emissions.The current monitoring device based on high performance magnetic sensor mainly includes cable current signal acquisition,sensor signal processing and RF communication.1)The signal acquisition module realizes the acquisition and preliminary amplification of three-phase line current signal.The magnetic sensor with highperformance tunneling magnetoresistance effect is used to complete signal collection.The sensor has high sensitivity and wide magnetic field measurement range.HDMI connection is used between signal acquisition module and data processing module.Through HDMI,the preliminary amplified differential signal can be transmitted to the device board.2)The data processing module is responsible for receiving and amplifying the differential signal transmitted by the signal acquisition module.The subsequent processing part adopts the hardware architecture of "FPGA and Arm".This paper comprehensively describes the hardware design of ADC,FPGA and Arm chips of this module,and introduces the peripheral circuit design,communication interface design,RTL design of FPGA,and the timing simulation which is carried out by Modelsim.3)The communication module can send the processed signal to the cloud server.The peripheral circuit of BC28 is designed and tested.Using NB-IoT communication mode can solve the problem of poor signal quality in traditional communication mode.Compared with LTE and GPRS base stations,the gain of this communication mode is about 20 d B higher,so that the device can maintain normal communication connection even when the signal of ordinary SIM card is very poor.By collecting data from various sensors,cloud server can analyze the operation of equipment in various enterprises,which can save labor cost and collect information quickly and conveniently.