Research On Photovoltaic System Confluence Detection Technology Based On Giant Magnetism Effect

In recent years,Photovoltaic Systems(PV)as part of the "smart grid" has been widely concerned by the researcher.The current detection of PV system is the key to ensure the safe,stable and efficient operation of PV system.Giant magnetoresistance(GMR)as an important field of magneto-electronics that has been rapidly developed in recent years.Compared with traditional current sensing technology,GMR has the advantage of high sensitivity,wide linear range,small volume and high temperature stability.GMR current sensor has a lot of research value and potential applications in the smart grid.This paper mainly studied the effect of sensor temperature stability,spatial position uncertainty and hysteresis phenomenon on sensor accuracy.By compare with other types of sensors,summarizes the advantages of GMR current sensor.The GMR.current sensor is designed and researched in the background of photovoltaic system convergence detection.Through the basic principles of GMR work,material classification and the basic structure of the sensor,presented a new current sensor based on GMR effect with a closed-loop configuration.The main components of the design sensor include the electromagnetic conversion unit,the signal amplification unit and the feedback compensation unit.Improve the ability of the sensor to measure the confluent current of the PV system.Design temperature compensation unit,to improve the effect of temperature on the output characteristics of the sensor.By adjusting the supply voltage to improve the sensor temperature characteristics,reduce the error more than 50%.The use of magnetic ring reduces the effect of spatial position uncertainty on sensor output,error is reduced more than 10 times.The use of Wheatstone bridge,magnetic ring and feedback compensation winding constitute a closed-loop system design,reduce the temperature drift,zero drift and hysteresis error of the sensor.Experimental results and simulation analysis show that the sensor based on GMR has good performance.