Research On And Development Of Current Sensor In Photovoltaic Power Generation Systems

With the increase extraction of the existing fossil fuels, for example, coal, oil, coupled with the gradual deterioration of the ecological environment, such as global warming,forcing people to seek clean energy and renewable resources. In recent decades, research and development of renewable energy has become more and more popular, so as the photovoltaic grid system. The accurate detection of the current is reliable and efficient operation of photovoltaic power generation. The research of high-performance current sensor is significant to improve the efficiency of the photovoltaic power generation system.Firstly, this paper analyzed the application prospect of photovoltaic power generation system, and a brief analysis of the development of sensor. Based on the characteristics of the current in PV system and fluxgate current sensor, the detection of fluxgate principle was chosen. Finally a new current sensor based on the fluxgate principle was designed to achieve the accurate of current.To achieve the measurement of AC and DC, this paper presents a closed-loop and compact current sensor. The sensor consists of two toroidal magnetic cores. One core works in fluxgate principle to measure DC and low frequency AC, and the other one is used as a current transformer for higher frequency application. The detailed structure design and working principle were described. The prototype was designed and tested for various performances, in the same time analysis the simulation and test results.The experimental result shows the presented current sensor has the advantages of high accuracy, low nonlinear error, and high sensitivity, greatly reduce the error caused by the magnetic hysteresis, and reduce the temperature drift and zero. It can detect both DC and AC current with a wide band width.As advance in power electronic products development, the need of high precision current sensors in high frequency application keeps increasing. Therefore, the designed current sensor in this paper has widely application prospects.