| Magnetically-Coupled Resonant Wireless Power Transfer(MCR-WPT)is a technology that uses the principle of electromagnetic resonance to achieve energy efficient and stable transmission.Compared with electromagnetic induction and microwave radiant transmission technologies,magnetic resonant transmission has better directionality and anti-jamming performance.Energy does not radiate outwards during transmission,and it has no harm to the surrounding environment and people.Its transmission distance can be reached the meter range.The advancement of science and technology and the need for practical applications have prompted the continuous development of MCR-WPT technology.In recent years,several receivers MCR-WPT systems have received more and more attention.Compared with a single-receiver,multi-receiver system has a higher research value due to its practicality.The structural difference between the two makes the theoretical research of multi-receiver systems not completely in accordance with a single-receiver system.Based on the lumped parameter theory,this paper analyzes and studies the single and multiple-receiver MCR-WPT systems.Focused on the impact of the load on the system parameters of a single-receiver system under maximum power transmission conditions(maximum power load)and the transmission characteristics of the resistive,inductive,and capacitive multi-receiver systems.Firstly,the basic theoretical analysis is carried out in the single-receiver system.The expression of the number of turns of the coil under optimal transmission efficiency is deduced,and the relationship between the maximum power load and the system parameters such as transmission distance,coupling coefficient,and system frequency is investigated.It is concluded that by analyzing the maximum power load,system parameters can be optimized and system transmission efficiency can be improved.Under the multi-receiver system,the transmission characteristics of three load properties(resistive,inductive,and capacitive)systems under different compensation structures are systematically studied using the PSPice circuit analysis software.Then model the system of each load based on the optimal compensation structure and obtain the expression of active power and efficiency,and explore the influence of mutual inductance,frequency and other parameters on the system of each load.Second,the multi-receiver MCR-WPT system experimental device design is completed,and a single and multi-receiver system experimental platform is built.Through the singlereceiver wireless transmission experiment,the correctness of the relationship between the maximum power load and various parameters of the system is verified,and the influence of distance and frequency on the transmission efficiency of the system is discussed.The simulation and experimental results show that there is a one-to-one correspondence between the maximum power load and the optimal system parameters.The load can be used to optimize the configuration system parameters so that the system can achieve maximum power transmission.Finally,in the multi-receiver system experiment,the transmission characteristics of the resistive,inductive,and capacitive dual-load systems were verified.Finally,two 10 W small-bulbs were successfully lit using a resistive double-load system with primary and secondary series compensation.The total system efficiency reaches 70%.Meanwhile,the transmission characteristics of the single and multi-receiver systems under the same parameters are compared,and the preliminary experimental research on the offset characteristics of multi-receiver systems is conducted. |
