A Wireless Charging System For Smart Home

In recent years,wireless is making great strides towards people.The number of scholars studying wireless charging system technology is increasing day by day,and the theoretical innovation and application results are fruitful.Especially in the application of smart home,the wireless charging revolution is unfolding.How to promote the practical application of smart home wireless charging is a hot spot of current research.The practicality and flexibility of the wireless charging system applied to the smart home are often the most concerned points of people.On the one hand,traditional radio frequency power transmission has low efficiency,large volume and poor practicability.On the other hand,the charging distance of magnetic resonance magnetic coupling transmission is short and the flexibility is poor.In view of this,thesis proposes a new type of electromagnetic lens,which is combined with the transmitting antenna to improve the transmission efficiency.And on the basis of the electromagnetic lens,around the receiving unit,the electromagnetic lens,receiving antenna and rectification circuit are innovatively integrated to further improve efficiency.At the same time,the path planning problem of wireless charging in smart home scenarios is researched and designed.The innovation of thesis lies in the following two aspects:(1)In order to improve the practicability of the wireless charging system for smart homes,an electromagnetic lens that can increase the antenna gain is designed in thesis to optimize the transmitting and receiving antennas,and a new focusing-receiving-rectifying unit is proposed.The transmitting antenna is a 4 part microstrip array,and the receiving antenna is a unit microstrip antenna.Starting from the transmitting end,after completing the design of the microstrip array antenna,according to the S parameter extraction method and the metamaterial theory,a spider web structure metamaterial is designed,and an electromagnetic lens is made by using its negative refraction characteristics.After the electromagnetic lens is fused with the transmitting antenna,the antenna gain can be increased from 7.22 d Bi to 9.44 d Bi.At the same time,its volume is 120×140×20 mm,which is much smaller than the traditional horn antenna.Starting from the receiving end,after the microstrip antenna is added with an electromagnetic lens,the gain is increased from 3.07 d Bi to 7.52 d Bi.Then the rectifier circuit selects the Class-F rectification structure,and determines the HSMS-282 C rectifier diode to meet the high-efficiency watt-level power output requirements.After testing,the rectification efficiency of the receiving unit is 62.1% when the receiving power is 26.13 d Bm.Finally,the overall debugging is carried out,and it is found that when the transmission power is about 50 d Bm,the maximum charging power of the six receiving units is 3.22 W at a distance of0.2 m,and the receiving-DC output efficiency can reach 53.78% at a distance of 1.4 m.(2)In order to improve the flexibility of the wireless charging system of the smart home,thesis optimizes the design of the autonomous charging method,and extends the path planning problem of the energy area according to the energy area formed by the transmitting antenna.Designed an antenna turntable for smart home charging scenarios,so that the energy beam can be aimed at the charging device,and then use ultra wide band to locate and verify the location of the powered device.After completing the aforementioned work,thesis proposes a path planning algorithm for RF wireless energy charging for smart home application scenarios.The system charges the most attractive device within the 2×2×0.5 m space according to the algorithm.After testing,it is found that the path planning algorithm significantly improves the flexibility of radio frequency wireless charging.