Design And Implementation Of Power Management System For Ocean Buoy Energy Collector

With the development of marine detection technology,marine buoys have become an important tool for marine exploration and offshore resource development.How to power systems powered by ocean buoys and achieve efficient use of limited energy is a key issue for marine buoy systems.Based on these problems,this paper designs an energy harvesting and power management system for marine buoys.Firstly,the output characteristics of photovoltaic cells and lithium-ion batteries were studied.The Simulink model based on photovoltaic cell equivalent circuit and lithium ion second-order Thevenin equivalent circuit was established.The simulation model embodies the output characteristics of photovoltaic cells and lithium-ion batteries.The results obtained,the technical research of energy management was carried out,the requirements of various parts of the system were analyzed,and the overall scheme of the system was designed.According to the overall scheme of the system,a hardware system including a solar energy collection module,a voltage conversion module,a single chip control module,a V/I detection module,a lithium battery protection module and a wave vibration energy collection module is designed.On this basis,the solar maximum power point tracking algorithm is designed to optimize the photovoltaic charging.The EKF-SOC algorithm based on the second-order Thevenin model is designed.The battery state is estimated based on the battery terminal voltage.The load power management is designed.The strategy adjusts the load working mode according to the input power of the external energy and the remaining battery power,thereby improving the energy utilization efficiency.Finally,the system was tested.The modules of the system can cooperate with the designed algorithm to achieve efficient collection of solar energy,estimation of the state of charge of the lithium battery and adjustment of the load working mode.At the same time,according to the system requirements,the voltage of the lithium battery terminal is realized to 3.3.V,±5V,±7V voltage conversion,ocean vibration energy harvester output energy collection and lithium battery protection on the hardware.The test results show that the system can work normally and stably to meet the design requirements.