Design And Implementation Of Power Management System For Solar Cell

In recent years, water pollution has gotten worse. The use of wireless sensor network has been widely applied to monitor the whole river basin. Because of the tiny volume, the energy of battery is limited, which won't meet the needs of long-term work. The problem of insufficient power supply can be solved by low carbon solar energy sources, which will make the sensor a self-powered one. According to the actual requirements of unattended monitoring power supply system, the work principle of lead-acid battery charging-discharging management is studied. Based on the advantages of solar energy and the demand of multi-voltage monitoring in field, a solar battery management system based on ARM processor with multiple output ports is researched. The input voltage is effectively boosted and the battery is charged by the application of charging module and DC-DC boost chip, and the outputs of 5V, 12 V and 24 V are achieved. The output voltage can be adjusted by changing the feedback values of the circuit. The maximum output power of this power management system is 20 W. In this paper, the AD in LPC2119 ARM microprocessor chip is utilized to monitor the battery power resulting in the management of charging-discharging circuit. Test and analysis of the output voltage of the system are carried out during the sunny, cloudy and rainy weather. The test results show that equipment can operate normally with load or without load in sunny and cloudy weather. In cloudy weather, the floating ranges of 5V, 12 V and 24 V voltage outputs are 0.004%, 0.020% and 4.825%, respectively, and the system operates in a relatively stable condition. In rainy weather, the open-circuit voltage and short-circuit current of the solar plate are 7mV and 1mA, respectively, and the equipment won't work.As a result, this work can be used as real-time monitoring of water quality, which avoids some unnecessary spending. The solar battery power management has the advantages of tiny volume and energy self-sufficiency, and therefore it will be widely applied in the unattended field.