CN211296325U

CN211296325U - Fractional order parallel-series electromagnetic field double-coupling wireless power transmission system

Info

Publication number: CN211296325U
Application number: CN201922287895.2U
Authority: CN
Inventors: 张波; 疏许健; 江彦伟; 魏芝浩
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2020-08-18
Anticipated expiration: 2029-12-17

Abstract

The utility model discloses a fractional order parallel-series electromagnetic field double coupling wireless electric energy transmission system, which comprises a high-frequency power current source, a fractional order parallel transmitting circuit, a fractional order series receiving circuit and a load; the fractional order parallel type transmitting circuit is composed of a primary side fractional order inductance coil, a first single-end coupling capacitance metal pole plate, a primary side fractional order compensation capacitance and a second single-end coupling capacitance metal pole plate which are connected in parallel, the fractional order series type receiving circuit is composed of a secondary side fractional order inductance coil, a third single-end coupling capacitance metal pole plate, a secondary side fractional order compensation capacitance and a fourth single-end coupling capacitance metal pole plate which are connected in series, and the first single-end coupling capacitance metal pole plate, the third single-end coupling capacitance metal pole plate, the second single-end coupling capacitance metal pole plate and the fourth single-end coupling capacitance metal pole plate are respectively matched into a pair of interactive coupling capacitance metal pole plates. The utility model discloses utilize the fractional order component to realize parallelly connected-tandem type electric field coupling and magnetic field coupling wireless power transmission common transmission energy, increased transmission distance and efficiency.

Description

Fractional order parallel-series electromagnetic field double-coupling wireless power transmission system

Technical Field

The utility model belongs to the technical field of space electric field coupling wireless power transmission's technique and specifically relates to indicate a fractional order is parallelly connected-series connection type electromagnetic field double coupling wireless power transmission system.

Background

According to different power transmission implementation mechanisms and modes, wireless power transmission technologies can be broadly classified into magnetic field coupling type wireless power transmission technologies, electric field coupling type wireless power transmission technologies, and microwave type wireless power transmission technologies. The microwave type has a long transmission distance, but has a very low efficiency, low power and serious dissipation, and is applied less at present. In practical applications, magnetic field coupling type and electric field coupling type have been studied in recent years because of their high transmission power and high efficiency. However, the transmission performance of both of these two methods is severely limited by the transmission distance. With the increase of the distance, the transmission efficiency will be greatly reduced, which is not beneficial to the practical application of the system. At present, the transmission distance of electric field coupling type wireless power transmission is mostly on the order of centimeters, and the transmission distance of magnetic field coupling type wireless power transmission is mostly on the order of tens of centimeters. How to effectively increase the distance of wireless power transmission and maintain the high efficiency of the system is an important problem facing the technology at present.

At present, conventional space electric field coupling type and magnetic field coupling type wireless power transmission systems may be classified into a series-series type, a series-parallel type, a parallel-series type, and a parallel-parallel type according to connection modes of inductors and capacitors. The transmitting circuit adopts a series connection suitable for a voltage source type inverter as a power supply to supply electric energy, and the receiving circuit adopts a series connection suitable for a current source type inverter as a power supply to supply electric energy. The receiving circuit is connected in series and is suitable for the application occasions of high-power loads, such as electric automobiles and the like, while the receiving circuit is connected in parallel and is suitable for the application occasions of low-power loads, such as consumer electronics products, such as mobile phones and the like, and different connection modes have great research significance and practical application value.

The concept of fractional order elements (i.e., fractional order inductance and fractional order capacitance) is derived from fractional order calculus. In fact, the inductance and capacitance elements of integer order do not exist in nature, but the fractional order of the inductance and capacitance adopted at present is close to 1. With the continuous and deep knowledge of the inductance and capacitance characteristics, the fractional order influence of the inductance and capacitance characteristics is considered, or the fractional order of the inductance and capacitance characteristics is purposefully utilized to improve the circuit performance, and the fractional order characteristics have proved to be more advantageous than the integer order components in some application occasions, such as the application in impedance matching circuits. However, the conventional parallel-series electric field coupling type and magnetic field coupling type wireless power transmission systems are implemented based on integer-order elements, the degree of freedom of system parameter design is small, the resonant frequency is easily affected by load and distance, the system is easily detuned, the adjustable factors of output power and transmission efficiency are few, and the system is limited by a high-frequency current source technology, so that the wireless power transmission with higher power and longer distance is difficult to implement.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art and provide a fractional order parallel-series electromagnetic field double-coupling wireless power transmission system, which utilizes fractional order elements to realize the common transmission energy of electric field coupling and magnetic field coupling wireless power transmission, so that the coupling mechanisms generated by two coupling modes are mutually overlapped, thereby not only greatly increasing the transmission distance and efficiency of the traditional parallel-series electric field coupling and magnetic field coupling wireless power transmission, but also increasing the dimensionality of parameter design, being easy for system optimization, having natural constant current output characteristic, effectively improving or even eliminating the influence of load and distance on the system resonance frequency, being beneficial to avoiding the occurrence of system detuning, reducing the current level requirement and design requirement of the system on a high-frequency current source, effectively improving the output power of the system, and being applicable to high-power application occasions, the performance of the system is completely different from that of the traditional integral-order parallel-series electric field coupling, magnetic field coupling and electromagnetic field double-coupling wireless power transmission system.

In order to achieve the above object, the present invention provides a technical solution: a fractional order parallel-series type electromagnetic field double-coupling wireless power transmission system comprises a high-frequency power current source, a fractional order parallel type transmitting circuit, a fractional order series type receiving circuit and a load, wherein the high-frequency power current source is connected with the fractional order parallel type transmitting circuit and provides electric energy for the whole system, and the fractional order series type receiving circuit is connected with the load; the fractional order parallel type transmitting circuit consists of a primary fractional order inductance coil, a first single-end coupling capacitance metal pole plate, a primary fractional order compensation capacitance and a second single-end coupling capacitance metal pole plate which are connected in parallel, the fractional order series type receiving circuit consists of a secondary fractional order inductance coil, a third single-end coupling capacitance metal pole plate, a secondary fractional order compensation capacitance and a fourth single-end coupling capacitance metal pole plate which are connected in series, the first single-end coupling capacitance metal pole plate and the third single-end coupling capacitance metal pole plate are matched into a pair of interactive coupling capacitance metal pole plates, the second single-end coupling capacitance metal pole plate and the fourth single-end coupling capacitance metal pole plate are matched into another pair of interactive coupling capacitance metal pole plates, and the primary fractional order inductance coil and the secondary fractional order inductance coil are coupled and transmit electric energy through a magnetic field, meanwhile, displacement current is generated between each two pairs of coupling capacitor metal polar plates, electric energy is transmitted through electric field coupling, coupling mechanisms generated by the two coupling modes are mutually overlapped to supply power to a load in a wireless mode, and natural constant current output can be realized and the transmission efficiency and the output power of the system can be improved by adjusting the order of the fractional order element.

Further, the differential relation between the voltage and the current of the primary side fractional order inductance coil and the secondary side fractional order inductance coil satisfies the following conditions:

the phase relation satisfies:

wherein i_LnIs the current of a fractional order inductor u_LnIs the voltage of a fractional order inductor, L_βnIs the inductance value of the fractional order inductor,

is the phase of a fractional order inductor, β_nIs the order of a fractional order inductor, and 0<β_n2, where n-1 or 2 denotes a transmitting circuit or a receiving circuit, respectively.

Further, the differential relation between the voltage and the current of the primary side fractional order compensation capacitor and the secondary side fractional order compensation capacitor meets the following requirements:

the phase relation satisfies:

wherein i_CnFor compensating the current of the capacitor in fractional order, u_CnCompensating the voltage of the capacitor for fractional order, C_αnIs the capacitance value of the fractional order compensation capacitor,

compensating the phase of the capacitor for fractional order, α_nCompensating the order of the capacitance for fractional order, and 0<α_n2, where n-1 or 2 denotes a transmitting circuit or a receiving circuit, respectively.

Furthermore, the capacitance values of the primary side fractional order compensation capacitor and the secondary side fractional order compensation capacitor are not only related to the load and the distance, but also related to the order of the fractional order element, and the influence of the load or distance change on the fractional order compensation capacitance value can be improved or even eliminated by adjusting the order of the fractional order element, so that the detuning of the system is improved or even avoided.

Further, the resonant frequency of the system depends on the order of the fractional order element, and the resonant frequency of the system can be reduced by adjusting the order of the fractional order element, so that the current level requirement and the design requirement of the system on the high-frequency current source are reduced.

Further, when the order of the primary side fractional order inductance coil and the secondary side fractional order inductance coil is 1, the primary side fractional order inductance coil and the secondary side fractional order inductance coil are integer order inductance coils; when the order of the primary side fractional order compensation capacitor and the secondary side fractional order compensation capacitor is 1, the primary side fractional order compensation capacitor and the secondary side fractional order compensation capacitor are integer order capacitors.

Compared with the prior art, the utility model, have following advantage and beneficial effect:

1. meanwhile, two transmission modes of electric field coupling and magnetic field coupling are utilized to wirelessly supply power to the load, so that the transmission efficiency of the system is improved compared with that of the traditional electric field coupling and magnetic field coupling wireless power transmission system, the transmission distance is increased, and long-distance and stable wireless power transmission is realized.

2. The space electric field and magnetic field double-coupling wireless power transmission realized by adopting the fractional order element is completely different from the traditional electric field and magnetic field coupling wireless power transmission system, the freedom degree of parameter selection is increased, and the output power and the transmission efficiency are easy to adjust.

3. By selecting the order of the fractional order element, the influence of the load and the distance on the fractional order compensation capacitance value can be effectively improved or even eliminated, and the detuning of the system is reduced or avoided.

4. The order of the fractional order element is selected, so that the resonant frequency of the system can be greatly reduced, the requirements on a high-frequency power current source and a power electronic device are reduced, and the design of an actual system is facilitated.

5. By adjusting the order of the fractional order element, the system can have the characteristic of natural constant current output, and the wireless power supply of the constant current load is facilitated.

6. By selecting the proper order of the fractional order element, the transmission power and efficiency can be higher, and the application in high-power occasions is facilitated.

Drawings

Fig. 1 is a schematic diagram of a specific system structure provided in the embodiment.

Fig. 2 is an equivalent circuit schematic diagram of a specific system provided in the embodiment.

Detailed Description

To further illustrate the aspects and features of the present invention, the following detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings, but the invention is not limited thereto.

As shown in fig. 1 and 2, the present inventionThe embodiment provides a fractional order parallel-series type electromagnetic field double-coupling wireless power transmission system, which comprises a high-frequency power current source I_sFractional order parallel type transmitting circuit, fractional order series type receiving circuit and load R_LSaid high-frequency power current source I_sIs connected with a fractional order parallel type transmitting circuit to provide electric energy for the whole system, and the fractional order series type receiving circuit is connected with a load R_LConnecting; the fractional order parallel type transmitting circuit is composed of a primary side fractional order inductance coil L connected in parallel_β1A first single-end coupling capacitor metal plate, a primary side fractional order compensation capacitor C_α1And a second single-end coupling capacitor metal polar plate, wherein the fractional order series receiving circuit comprises a secondary fractional order inductance coil L connected in series_β2A third single-end coupling capacitor metal polar plate, a secondary side fractional order compensation capacitor C_α2And a fourth single-end coupling capacitor metal plate, wherein the first single-end coupling capacitor metal plate and the third single-end coupling capacitor metal plate are matched into a pair of interactive coupling capacitor metal plates C_c1The second single-end coupling capacitor metal polar plate and the fourth single-end coupling capacitor metal polar plate are matched into another pair of interactive coupling capacitor metal polar plates C_c2The primary side fractional order inductance coil L_β1And secondary fractional order inductance coil L_β2The two pairs of coupling capacitor metal polar plates C transmit electric energy through magnetic field coupling_c1、C_c2Displacement current is generated between the two, electric energy is transmitted through electric field coupling, and coupling mechanisms generated by the two coupling modes are mutually superposed to form a load R_LAnd wireless power supply is carried out, and natural constant current output can be realized and the transmission efficiency and the output power of the system can be improved by adjusting the order of the fractional order element.

Wherein, the order and inductance of the primary side fractional order inductance coil and the secondary side fractional order inductance coil are β respectively₁、β₂And L_β1、L_β2，β₁、β₂Satisfies 0<β_1、2The order and capacity of the primary side fractional order compensation capacitor and the secondary side fractional order compensation capacitor are α respectively₁、α₂And C_α1、C_α2，α₁、α₂Satisfies 0<α_1、2Less than or equal to 2. Impedance expressions of the primary side fractional order inductance coil, the primary side fractional order compensation capacitor, the secondary side fractional order inductance coil and the secondary side fractional order compensation capacitor are respectively as follows:

as can be seen from the above impedance expression, the fractional order inductance coil can be equivalent to a series connection of an integer order resistance and an integer order inductance which change with the operating frequency and the order, and the fractional order compensation capacitance can be equivalent to a series connection of an integer order resistance and an integer order capacitance which change with the operating frequency and the order, that is:

according to the coupled mode theory, the coupled mode equation of the system is as follows:

in the formula, a₁And a₂The energy storage method is characterized by comprising the following steps of (1) defining a complex variable stored by a primary side resonant circuit and a secondary side resonant circuit, wherein the square of a module value of the complex variable represents the energy stored by the resonant circuit, and the specific expression is as follows:

in the formula i₁And i₂Current of the transmitting circuit and current of the receiving circuit, u, respectively_{Cα1_eq}And u_{Cα2_eq}The voltage of imaginary part impedance components of the primary side fractional order compensation capacitor and the secondary side fractional order compensation capacitor are respectively.

τ₁、τ₂Total loss rate of the transmitting circuit and total loss rate of the receiving circuit, and τ₁＝τ_Cα1+τ_Lβ1，τ₂＝τ_Cα2+τ_Lβ2+τ_LIn which τ is_Cα1、τ_Lβ1、τ_Cα2、τ_Lβ2Respectively the loss rate, tau, of each element in the circuit_LFor the load factor, the specific expression is as follows:

the load factor is:

ω₁、ω₂the resonant angular frequencies of the transmitter and receiver, respectively, are expressed as follows:

from the above formula, the resonance angular frequency of the system depends not only on the inductance value of the fractional order inductance coil and the capacitance value of the fractional order compensation capacitor, but also on the orders of the fractional order inductance coil and the fractional order compensation capacitor, whereas the resonance angular frequency of the conventional integer order electric field and magnetic field coupling wireless power transmission system is determined only by the inductance value and the capacitance value.

Is the electromagnetic field energy coupling coefficient, where k_cIs the electric field coupling coefficient, k_mFor the mutual inductance coupling coefficient, the specific expression is as follows:

here, the first and second liquid crystal display panels are,

C_c1and C_c2Is an equivalent capacitance of a single pair of coupled metal plates, generally having C_c1≈C_c2S is the area of the plate, d is the transmission distance, and k_c、k_m<<1。

Fe^jωtFor applying an excitation to an expression in the coupled-mode equation, an

I_sIs the effective value of the external high-frequency power current source.

According to the coupled modeThe process can obtain a₁And a₂The steady state solution of (c) is:

the energy | a of the transmitting circuit and the receiving circuit₁|²、|a₂|²Respectively as follows:

the output power and transmission efficiency of the system thus obtained are:

in order to make the system transmitting circuit and receiving circuit implement resonance compensation of the system, the working angular frequency satisfies: omega-omega₁＝ω₂The output power and transmission efficiency of the system can then be expressed as:

from the above equation, the output power and transmission efficiency of the system not only depend on the working angular frequency ω of the power supply and the coupling capacitance C_cDependent on the mutual inductance M, and also on the order β of the fractional-order inductor₁、β₂And fractional order compensation capacitor α₁、α₂Is related to the order of (a). The output power and the transmission efficiency of the traditional electromagnetic field double-coupling wireless power transmission system are only connected with the working angular frequency omega and the coupling capacitance value C_cAnd the mutual inductance M.

According to the above analysis, the utility model discloses utilize fractional order component to realize parallelly connected-tandem type electric field coupling and magnetic field coupling wireless power transmission common transmission energy, make the coupling mechanism that two kinds of coupling modes produced superpose each other, not only greatly increased traditional parallelly connected-tandem type electric field coupling and magnetic field coupling wireless power transmission's transmission distance and efficiency, parameter design's dimension has still been increased, easily system optimization, and have natural constant current output characteristic, can effectively improve even eliminate the influence of load and distance to system resonant frequency, thereby be favorable to avoiding the emergence of system detuning, reduce system's current grade requirement and design requirement to high frequency current source, and can effectively improve the output of system, be applicable to powerful application scenario, the performance also is different from traditional integer order parallelly connected-tandem type electric field coupling completely, Magnetic field coupling and electromagnetic field double coupling's wireless power transmission system, the utility model discloses the advantage of system is obvious, is worth promoting.

The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be equivalent replacement modes, and all are included in the scope of the present invention.

Claims

1. A fractional order parallel-series electromagnetic field double-coupling wireless power transmission system is characterized in that: the system comprises a high frequency power current source (I)_s) Fractional order parallel type transmission circuit, fractional order series type reception circuit, and load (R)_L) Said high-frequency power current source (I)_s) Connected with a fractional order parallel type transmitting circuit for supplying power to the whole system, and a fractional order series type receiving circuit and a load (R)_L) Connecting; the fractional order parallel type transmitting circuit comprises a primary side fractional order inductance coil (L) connected in parallel_β1) A first single-end coupling capacitor metal plate, a primary side fractional order compensation capacitor (C)_α1) And a second single-end coupling capacitor metal plate, the fractional order series receiving circuit is composed of series connectionConnected secondary fractional order inductor (L)_β2) A third single-end coupling capacitor metal polar plate, a secondary side fractional order compensation capacitor (C)_α2) And a fourth single-ended coupling capacitor metal plate, wherein the first single-ended coupling capacitor metal plate and the third single-ended coupling capacitor metal plate are matched into a pair of interacting coupling capacitor metal plates (C)_c1) The second single-end coupling capacitor metal polar plate and the fourth single-end coupling capacitor metal polar plate are matched into another pair of interactive coupling capacitor metal polar plates (C)_c2) Said primary side fractional order inductor (L)_β1) And a secondary fractional order inductor (L)_β2) The two pairs of coupling capacitance metal polar plates (C) transmit electric energy through magnetic field coupling_c1、C_c2) Displacement current is generated between the two, electric energy is transmitted through electric field coupling, and coupling mechanisms generated by the two coupling modes are mutually superposed to form a load (R)_L) And wireless power supply is carried out, and natural constant current output can be realized and the transmission efficiency and the output power of the system can be improved by adjusting the order of the fractional order element.

2. The fractional order parallel-series type electromagnetic field double-coupling wireless power transmission system according to claim 1, wherein: the primary side fractional order inductor (L)_β1) And a secondary fractional order inductor (L)_β2) The voltage and current differential relation satisfies:

the phase relation satisfies:

3. The fractional order parallel-series type electromagnetic field double-coupling wireless power transmission system according to claim 1, wherein: the primary side fractional order compensation capacitor (C)_α1) And secondary side fractional order compensation capacitance (C)_α2) The voltage and current differential relation satisfies:

the phase relation satisfies: