Wireless Power Transfer Guided On A Two-Dimensional Plane

In recent years,with the development of wireless communication,robotics and autonomous driving technologies,wireless power transfer(WPT)has become an important technology,which provides new possibilities for getting rid of power supply limitations,energy saving and emission reduction.Based on the principle of magnetic coupling resonance,WPT systems have evolved from powering fixed-position receivers to powering dynamic receivers.And the research on powering dynamic receivers has also transitioned from one-dimensional power transmission to power transmission with multiple degrees of freedom.This thesis focuses on the problem of dynamic receiver power supply on a twodimensional(2D)plane.By designing dual-frequency switchable resonant units to form a 2D WPT plane,effective and directional power transmission and isolation on the plane can be achieved.The proposed WPT planar system is able to independently determine the position of the receiver,plan the optimal power transfer route,and adjust the state of resonant units in real time.Firstly,this thesis proposes a method for constructing a single-frequency two-dimensional WPT plane with magnetically coupled resonant units.The power transmission and isolation between magnetically coupled resonant circuits are analyzed theoretically and experimentally.The equivalent circuit model is established to analyze transmission efficiency of a power transfer route.And the design and parameters of the unit of optimized in electromagnetic simulation software.On a 2D plane that is composed of 10 × 10 single-frequency planar resonant units,the directional routing of power is realized,and the transmission performance is tested in single receiver,dual receiver,and obstacle avoidance situations.The experimental results show that after the coupling of 8 resonant units,the AC power transmission efficiency of single-receiver situation is 52.7%.Secondly,in view of the problem of control circuit power supply that exists in singlefrequency two-dimensional WPT plane,and the problem of weak coupling between the tiled square planar coils,this thesis improves the design of the resonant unit and the twodimensional WPT plane.A dual-frequency 2D WPT plane is proposed.There is a stronger coupling between the units on this plane,and the units have two resonance states,which are respectively used for power supply of the receiver and the control circuit of the units outside the power transfer routes.The state of each resonant unit is wirelessly controlled by computer.All resonant units are energy self-sustaining without carrying any energy storage elements,therefore real-time adjustment of the power transfer route from the transmitting coil to the receiver can be realized.Experimental results show that the power transmission efficiency of a single receiver reaches 93.3%after the coupling of 5 resonant units.Theoretical calculation,simulation and experiment are mutually verified,proving the feasibility of dual-frequency 2D WPT plane.Additionally,this paper proposes a method of introducing dynamic routing algorithms to plan the optimal power transfer route on the 2D plane.For the dual-frequency twodimensional plane and dynamic receiver proposed in this system,the constraint rule of the optimal route should not only satisfy the minimum number of units passing through from the transmitting coil to the receiving coil,but also consider the number of units that need to switch state from the previous moment to the next moment in order to reduce the redundancy of system control.These constraint rules are applicable to multi-objective situations as well.Therefore,the breadth-first search(BFS)and A-star algorithm are compared.This thesis optimizes the classic A-star algorithm,and proposes a memory-optimized A-star routing algorithm and a multi-objective optimized A-star routing algorithm that meet the needs of this system.Compared with the classic A-star algorithm,the routing results show that the algorithm proposed in this paper can deal with various situations on the plane and plan the correct optimal power transfer route.Finally,this paper proposes a receiver positioning method based on the electromagnetic resonance characteristics of the system,which gets rid of the traditional positioning methods that rely on visible light and electromagnetic waves in radiation field.The positioning of receiver is achieved by using the non-radiation field reflection characteristics of the existing two-dimensional plane,without introducing additional hardware systems.The active electromagnetic positioning method measures the reflection characteristics of the broadband frequency-sweeping signal at the port of transmitting coil,extracts features of the reflection coefficient curve,and obtains the position of receiver through statistical feature fitting.This research proposes a dual-frequency two-dimensional wireless power transfer system to address wireless power supply of mobile receivers,which can realize autonomous receiver positioning,power transfer route planning,and adjust the state of the resonant units on the plane without adding any energy storage elements to update and optimize power transfer route in real-time.Consequently,dynamic receivers can be continuously powered on this plane.The method and system proposed in this study have broad application prospects in the fields of industrial robots,unmanned logistics,and public transportation,and provide strong technical support for research and application in related fields.