The Design And Implementation Of A Hybrid Energy Harvesting System For Environmental Multiple Energy Sources

With the increasing shortage of global energy,how to efficiently use renewable energy has become a hot issue for people.In recent years,large-scale sensor networks and Internet of Things technologies have been widely used,and the environment in which people live is flooded with a large number of electronic devices.These electronic devices often use batteries to power them.When the battery is exhausted,replacing batteries in large quantities will definitely increase system maintenance costs.Based on the above two points,environmental energy harvesting technology has begun to receive close attention from researchers.At present,there are many types of energy in environmental species,but they are often random and discontinuous,and the energy density of some energy sources is low,resulting in limited energy collection efficiency in a single form.Therefore,this paper designs a hybrid energy harvesting system that can simultaneously collect energy in three forms: radio frequency energy,solar energy,and thermal energy.First,three energy collection devices are designed and manufactured in this paper.This paper designs two kinds of dual-frequency receiving antennas covering the WLAN operating frequency band: microstrip butterfly slot antennas and printed dipole antennas.The former has a higher gain,and the gain is greater than 8.7dBi in the operating frequency band,and it can reach 10 dBi at the highest point.The latter has a small volume and good omnidirectionality,and can receive electromagnetic wave energy at any angle in space.Subsequently,a sensitized dye solar cell was produced in this paper.The photovoltaic conversion efficiency of the battery was improved from 3.57% to 6.44% by improving the photoanode manufacturing process,improving the materials used for the counter electrode,and using efficient electrolytes and sensitizing dyes.Finally,this paper chooses an efficient thermoelectric chip as the thermal energy harvester.Then,the rectifier of the receiving antenna and the power management module of the system are designed.In this paper,through simulation of different circuit topologies,a single-tube series rectifier structure that performs well under low power input is selected.The rectifier circuit was made into a real object for testing,and the results showed that the rectification efficiency of the 2.4GHz rectifier circuit and the 5.8GHz rectifier circuit reached 57% and 37% when the input was 0 dBm.The power management module takes the bq25570 chip as the core and builds its supporting circuit to realize several functions such as boost input,buck output,over-voltage / under-voltage protection,and maximum power input.Finally,this article builds the entire hybrid energy harvesting system,and fully considers the impacts existing between several parts of the system when building.During the test,the output performance of the system’s single energy harvest was first tested,and then the output effect of the system’s mixed energy harvest was tested in four typical cases.It is concluded that compared with a single energy input,the system’s acquisition efficiency is significantly improved when mixed energy input;at the same time,the system’s sensitivity to RF energy signal acquisition is also significantly improved when mixed energy input.