Mobile Communication Base Stations Use Photovoltaic Controller

With optimization of the global energy structure, solar energy enjoys panegyric as one of the clean renewable energy, and photovoltaic power generation has been paid more and more attention on. At present, PV generation systems have been applied increasingly in the base-station of mobile communication system, so developing a reliable, low cost and convenient maintenance PV generation system has become an urgent issue.As one of the pivotal parts in the photovoltaic generation system, the solar controller is responsible for providing the optimum charging current of the storage battery, also preventing the storage battery from damage of overcharging and overdischarging, and plays the role of prolonging the service life of storage battery and improving energy efficiency. The research and development of the photovoltaic controller with excellent performance has important significance to the solar energy utilized efficiently and applied extensively.Based on the study of main functions of photovoltaic controller and the basic principle of storage battery charging and discharging, this thesis chiefly researches on PV power control system for the mobile communication base station from the following aspects:1. Control strategy which makes higher quality of the battery charging and discharging and higher efficiency is determined as the loop negative feedback digital PI control with the MPPT algorithm based on the research of the basic principle of storage battery charging and discharging, solar cells mathematical model and main functions of photovoltaic controller.2. Modular design of the PV power control system hardware circuit,including the designs for power circuit, master control circuit, auxiliary power circuit, signal acquisition and processing circuit, communication-interface circuit and so on.3. Software programming. The software is divided into four subprograms including main program, charge-discharge control subprogram, interface-communication subprogram, and signal acquisition and processing subprogram. Three stages for charging control were determined:constant current charging, constant voltage charging and floating charging, and MPPT technology is realized in constant current stage, realizing input over-voltage, under-voltage of storage battery protection and output overload and short circuit protection, the controller also possess RS485 and GSM communication functions.4. Prototype development and experiment study. A mobile base-station using photovoltaic control power test prototype was completed and the research is based on combining the software with hardware. Experiments proved this design increased the solar energy conversion efficiency and stability of the storage battery charging and discharging, plays certain promoting role in the promotion and practicability of photovoltaic power generation.