Design Of Dual-load Magnetically Coupled Resonant Wireless Power Transmission

As a novel power supply technology,wireless power transfer technology has gradually become a research hotspot.The magnetic coupled resonant wireless power transfer is main research direction rely on its advantages of high efficiency,medium transmission distance,and less dependence on transmission media.The primary research of MCR-WPT focuses on the traditional "one-to-one" resonant coil transmission mode.Once it requires to meet the demand of timeliness,there may be multiple receiving load applications.This thesis analyzes the dual-load coil mode.When the coil distance or load resistance changes,the output performance of the system will be affected.It is necessary to develop a reliable control strategy for providing a stable voltage for the load.First,by comparing with the basic analysis theory of MCR-WPT,this thesis will discuss the advantages and disadvantages of the compensation network structure upon equivalent circuit theory.And then the second step is to establish the equivalent transmission model of the dual-load MCRWPT system to complete the derivation of power and efficiency formula and explore power and efficiency curve characteristics when the load is in different positions analyzed by Matlab.Aiming to keep the output voltage stable,the third step is to develop a closed-loop control system based on DC conversion at the receiver and adopting the integral separation PID algorithm to control the DC converter’s duty cycle in real-time to realize the stable output of the system.After that,the equivalent circuit model is built by Matlab/Simulink simulation platform.Meanwhile,the simulation research is carried out for load conversion and coupling coefficient conversion to verify the voltage stabilization control strategy’s feasibility.The design of the dual-load MCR-WPT system’s hardware circuit is finished which is mainly for the parameter calculation and component selection of the inverter circuit,DC conversion circuit,DSP control circuit,and other circuits.Finally,a prototype of the dual-load MCR-WPT system is built for efficiency optimization experiment and the output voltage stabilization test and the experimental results is essentially in agreement with the theoretical analysis.It validates that when the dual-load coils are at the same side symmetrical position,the effectiveness of the system improves the transmission efficiency by appropriate reactance compensation at the receiver and the system maintains a stable output voltage during load conversion and coupling coefficient conversion.