Design of a household solar LED lighting system

For the shortage of electricity in remote areas, many household solar LED lighting systems have been developed, but most of them have simple structure, low charge and discharge efficiency, poor stability and short battery life. Therefore, a household solar LED lighting system is designed in this paper. The system mainly uses the bidirectional BUCK/BOOST circuit as the main circuit, reducing the volume cost and reducing the switching loss of the circuit, and taking the STM32 single chip as the control core. The control strategy is as follows: (1) The battery charge and discharge management strategy based on the carrier stack thought is added to control battery charging and discharging to maximize battery life; (2) The MPPT (maximum power point tracking) algorithm based on variable step size disturbance observation method is used to improve the utilization of solar energy; (3) Based on solar panels and batteries, three charging modes are selected in different states, which are MPPT charging, constant voltage charging and floating charging to improve the efficiency of the system; (4) To protect the battery from overcharge, overvoltage and return differential, a protection strategy is designed to reduce battery damage. After testing, the system has high charge/discharge efficiency and good stability, and the service life of the battery has been effectively extended.