CN-115664050-B - Multi-load wireless power transmission system based on high-order Anti-PT symmetry

Abstract

The invention provides a multi-load wireless power transmission system based on high-order Anti-PT symmetry, which is convenient to construct an effective Anti-PT non-early system by introducing a W-shaped Anti-resonance mode into a basic WPT platform. Combining the "energy level attraction" of the Anti-resonance mode with the "energy level cleavage" of the Anti-resonance mode and the resonance mode, the "energy level pinning" effect of the high-order Anti-PT symmetry was studied. Compared with the traditional resonant WPT, the anti-resonant WPT has higher safety, stability, transmission efficiency and flexibility. Considering miniaturization and integration of devices, a super-structure coil is designed by adopting a synthetic dimension and is used for constructing a high-order Anti-PT symmetrical system, so that the multi-load high-efficiency WPT is realized. The novel WPT technology based on the 'energy level pinning' effect of high-order Anti-PT symmetry not only provides a good application research platform for enriching non-hermetia physics.

Inventors

• GUO ZHIWEI
• LI YUNHUI
• YANG FENGQING
• WU XIAN
• ZHU KEJIA
• JIANG JUN
• SUN YONG
• JIANG HAITAO
• CHEN HONG

Assignees

• 同济大学

Dates

Publication Date

20260512

Application Date

20221108

Claims (7)

1. 1. A multi-load wireless power transmission system based on high-order Anti-PT symmetry is characterized by comprising a W-shaped Anti-resonance structure and Lorentz resonance structure which are coupled to form a three-order Anti-PT symmetrical WPT system, wherein two detuned modes are adopted for the W-shaped Anti-resonance structure And The coupling coefficient between them is , The equation of motion of the system is: formula (1) Therein, wherein And Respectively represent resonant modes Is a radiation loss and an intrinsic loss of (a); representing near field coupling strength between the antiresonance structure and the resonant structure; And Representing electromagnetic waves externally input to the antiresonance structure, taking into account , Ignoring intrinsic losses of the system And taking into account the reflection-free condition The kinetic equation of the system is expressed as: Formula (2) The equivalent hamiltonian of the system at this point is denoted as: Formula (3) Wherein the method comprises the steps of Representing the center frequency of the resonance and anti-resonance system, Representing the amount of frequency mismatch of the antiresonant structure, Representing the coupling strength of the Anti-resonant structure and the resonant structure, and determining from the formula (3) that the non-hermite system satisfies the third-order Anti-PT symmetry condition And the centre of symmetry of the system is in frequency space 。
2. 2. The multi-load wireless power transfer system based on high-order Anti-PT symmetry according to claim 1, wherein for the sake of no loss of generality, the following is made At this time, different coupling strengths The system mode is combined at the position corresponding to the singular point of the non-hermitian system.
3. 3. The high-order Anti-PT symmetric multi-load wireless power transfer system of claim 1, wherein the transfer efficiency of the WPT system symmetric by the W-type antiresonance structure and Lorentz resonant structure third order Anti-PT is expressed as: Formula (4) Therein, wherein Representing the signal output from the resonant structure, The amplitude of the resonant structure is represented, And Representing the amplitude of the detuned mode of the antiresonant structure at a fixed operating frequency The transmission efficiency of the system is constant as follows 。
4. 4. The multi-load wireless power transfer system based on high-order Anti-PT symmetry of claim 1, further comprising utilizing a planar super-structure coil to design an Anti-resonance transmitting coil ATC, then matching a receiving coil RC, and constructing a compact three-order Anti-PT symmetric WPT system.
5. 5. The multi-load wireless power transfer system based on high-order Anti-PT symmetry of claim 4, wherein the radii of ATC and RC are respectively used And To be expressed when fixed 15 At cm, the near field coupling coefficient of ATC and RC is exponentially attenuated as the area ratio of the transmitting/receiving end increases 。
6. 6. The multi-load wireless power transfer system based on high-order Anti-PT symmetry of claim 5, wherein the bypass capacitance is utilized as an equivalent circuit diagram of ATC for the synthesized dimension when the ac supply voltage is When, the Kirchhoff equation for ATC is expressed as: Formula (5) Therein, wherein And Respectively representing currents in different directions; representing the power supply impedance and due to the symmetry of the ATC structure, And ; Assume that , , The amplitude of the ATC structural mode is expressed as Then formula (5) is rewritten as Formula (6) The equivalent gain and effective coupling of the ATC structure are respectively obtained as And 。
7. 7. The multi-load wireless power transfer system based on high-order Anti-PT symmetry of claim 6, further comprising proposing a synthesized WPT system of three-order Anti-PT symmetry assuming , A kind of electronic device The Kirchhoff equation for the system at this time is expressed as: Formula (7) Here, the Mutual inductance representing the resultant ATC and TC; representing the coupling factors of different loads, obtaining the dynamic equation of ATC and RC coupling system Formula (8) Using unitary transformations A kind of electronic device The equation of motion of the system is expressed as Formula (8) Setting up And The kinetic equation derived from Kirchhoff equation is expressed as: Formula (10) When defining And When the equivalent Hamiltonian quantity of the system is expressed as a formula (3), the system meets the Anti-PT symmetry condition 。

Description

Multi-load wireless power transmission system based on high-order Anti-PT symmetry Technical Field The invention relates to the technical field of wireless power transmission, in particular to a multi-load wireless power transmission system which realizes high efficiency and stability based on an energy level pinning effect of an Anti-resonance state in a high-order Anti-space-time (Anti-PT) symmetrical system. Background The wireless power transmission (Wireless Power Transfer, WPT) is a technology for directly transmitting power from a power supply to a load by using electromagnetic waves, opens up a new way for people to use the power, and has important application value for occasions requiring high-degree-of-freedom power supply such as consumer electronics industry, automatic industrial workshops, artificial intelligent platforms and the like. However, the conventional WPT is severely limited by the transmission distance, and researchers have found that the magnetic resonance WPT can achieve high-efficiency transmission at a medium distance through a near-field coupling effect between two resonance coils (in which coupling strength is exponentially attenuated as the coil distance increases), thereby promoting the wide development of non-radiative magnetic resonance WPT. Nevertheless, the most obvious disadvantage of magnetic resonance WPT is that it is difficult to achieve both high efficiency and strong stability of the energy transfer, on the one hand, for strong coupling situations (smaller resonant coil spacing) a high transfer efficiency can be guaranteed, but the operating frequency will split due to near field coupling. Therefore, when the distance between the transmitting end resonant coil and the receiving end resonant coil is changed, the optimal working frequency of the system is shifted, so that the stability of the device is reduced. On the other hand, for the weak coupling case (smaller resonant coil pitch), the operating frequency can be ensured to be stable, but the transmission efficiency will be significantly reduced. Therefore, how to achieve stable energy transmission while maintaining high transmission efficiency of the system becomes a difficult reconciliation contradiction in the current remote WPT. To solve this problem, researchers have proposed using a frequency tracking circuit to continuously change the operating frequency of the system, and switching the optimum operating frequency to ensure efficient WPT after scanning the frequency with the highest efficiency. Although the scheme can realize higher transmission efficiency, the frequency scanning tracking circuit of the system not only increases the complexity of the equipment construction, but also puts higher requirements on the performance of circuit elements, so that the complex circuit matching network still has limitations in many application scenes. In recent years, the remarkable development of non-hermeticity has provided new principle support for modern WPT technology innovation. Researchers symmetrically apply the Parity-Time (PT) in non-hermitian theory to the WPT system, and the robust WPT of the adaptive tracking of the optimal working frequency of the system is realized through a nonlinear circuit. The scheme is limited by the core element operational amplifier, and the maximum power of the system is difficult to reach more than 10W, but the scheme inspires people to explore a new research view angle from a new physical principle, thereby promoting the generation of new technology and new devices. The current WPT technology based on a frequency tracking circuit and a nonlinear effect gradually solves the problem of locking the optimal working frequency of the WPT, but the WPT technology still has strong sensitivity to a complex circuit and nonlinear elements inside a device, so the stability of the whole system is still poor. In addition, how to realize the stable and efficient WPT with long distance, high area ratio of transmitting/receiving end and multiple loads is still an important scientific difficulty to be solved. Disclosure of Invention Aiming at the scientific problems, the invention provides a W-shaped anti-resonance structure for the first time. By introducing this Anti-resonance mode in the basic WPT platform we can conveniently construct an efficient Anti-Parity-Time (Anti-PT) non-hermite system. Combining the "energy level attraction" of the Anti-resonance mode with the "energy level cleavage" of the Anti-resonance mode and the resonance mode, the "energy level pinning" effect of the high-order Anti-PT symmetry was studied. The technical scheme adopted by the invention is as follows: A multi-load wireless power transmission system based on high-order Anti-PT symmetry comprises a three-order Anti-PT symmetrical WPT system constructed by utilizing the coupling of a W-type Anti-resonance structure and a Lorentz resonance structure, wherein for the W-type Anti-resonance structure, the coupling coe