CN211296326U - Fractional order parallel-series electric field coupling wireless power transmission system - Google Patents

Abstract

The utility model discloses a fractional order parallel-series type electric field coupling wireless electric energy transmission system, including high-frequency power current source, fractional order parallel type transmitting circuit, fractional order series type receiving circuit and coupling capacitance metal polar plate, high-frequency power current source and fractional order series type transmitting circuit parallel connection, fractional order parallel type transmitting circuit and fractional order series type receiving circuit link to each other through two coupling capacitance metal polar plates that are parallelly connected; the fractional order parallel type transmitting circuit is a resonant circuit formed by connecting a primary fractional order inductor and a primary fractional order compensation capacitor in parallel, and the fractional order series type receiving circuit is a resonant circuit formed by connecting a secondary fractional order inductor, a secondary fractional order compensation capacitor and a load in series. The utility model discloses utilize fractional order component to realize electric field coupling wireless power transmission, increased parametric design's dimensionality, easily system optimization has natural constant current output characteristic, improves and eliminates load and the influence of distance to system resonant frequency even.

Description

Fractional order parallel-series electric field 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 electric field coupling wireless power transmission system.

Background

According to different power transmission implementation mechanisms and modes, wireless power transmission technologies can be broadly classified into inductive coupling type wireless power transmission technologies, magnetic resonance coupling type wireless power transmission technologies, microwave type wireless power transmission technologies, and electric field coupling type wireless power transmission technologies. Among them, the inductive coupling type, the magnetic resonance coupling type, and the electric field coupling type wireless power transmission technology are most widely studied.

As one of the most widely studied wireless power transmission technologies, the electric field coupling wireless power transmission technology can achieve the same level of transmission distance, output power and transmission efficiency as compared with the inductive coupling wireless power transmission technology, but the energy transmission form is an interactive electric field, the transmission of energy is to transmit energy by using a metal barrier as a part of a coupling plate without being blocked by the metal barrier, and the electric field is basically limited to exist between the coupling plates, so that the electromagnetic interference is greatly reduced. Compared with the magnetic resonance coupling wireless power transmission technology, the electric field coupling mechanism is simple, light and thin, low in cost and easy to change in shape, most of electric flux of the electric field coupling mechanism is distributed between the coupling polar plates in the working state, electromagnetic interference on the surrounding environment is small, and in addition, when metal barriers exist between or around the electric field coupling mechanism, eddy current loss is not generated on the conductor.

At present, conventional space electric field coupling 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 different 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 space electric field coupling wireless power transmission system is realized based on an integer order element, the degree of freedom of system parameter design is small, the resonant frequency is affected by a load and a distance, the detuning is easy, the adjustable factors of the output power and the transmission efficiency are few, and the wireless power transmission with higher power and longer distance is difficult to realize due to the limitation of a high-frequency current source technology.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome prior art's shortcoming and not enough, a fractional order is parallelly connected-series connection type electric field coupling wireless power transmission system is proposed, utilize fractional order component to realize electric field coupling wireless power transmission, parameter design's dimensionality has been increased, easily system optimization, natural constant current output characteristic has, can effectively improve or even eliminate load and the influence of distance to system resonant frequency, thereby be favorable to avoiding the emergence of system detuning, the lowering system is to the current level requirement and the designing requirement of high frequency current source, and can effectively improve the output of system, the powerful application scenario that is applicable to, the performance is distinguished from traditional integer order and connects parallelly connected-series connection compensation type electric field coupling wireless power transmission system completely.

In order to achieve the above object, the present invention provides a technical solution: a fractional order parallel-series type electric field coupling wireless electric energy 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 coupling capacitor metal polar plate, wherein the high-frequency power current source is connected with the fractional order series type transmitting circuit in parallel; the fractional order parallel type transmitting circuit is a resonant circuit formed by connecting a primary fractional order inductor and a primary fractional order compensation capacitor in parallel, the fractional order series type receiving circuit is a resonant circuit formed by connecting a secondary fractional order inductor, a secondary fractional order compensation capacitor and a load in series, and natural constant current output and system output power improvement can be achieved by adjusting the order of a fractional order element.

Further, the differential relation between the voltage and the current of the primary side fractional order inductor and the secondary side fractional order inductor satisfies the following condition:

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 inductance,

is the phase of a fractional order inductor, β_nIs the order of fractional order inductance, 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 the distance change on the fractional order compensation capacitor can be reduced or even eliminated by adjusting the order of the fractional order element, so that the detuning of the system is reduced or eliminated.

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 inductor and the secondary side fractional order inductor is 1, the primary side fractional order inductor and the secondary side fractional order inductor are integer order inductors; 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. the space electric field coupling wireless power transmission realized by the fractional order element is completely different from the prior parallel-series electric field coupling wireless power transmission system, the freedom degree of parameter selection is increased, and the system optimization is easy.

2. 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.

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

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

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 fig. 2, the fractional order parallel-serial electric field coupling wireless power transmission system provided in this embodiment includes a high-frequency power current source I_sA fractional order parallel type transmitting circuit, a fractional order series type receiving circuit and a coupling capacitance metal polar plate, the high-frequency power current source I_sThe fractional order parallel type transmitting circuit and the fractional order series type receiving circuit are connected in parallel through two coupling capacitance metal pole plates C in parallel_c1、C_c2Connecting, and further realizing wireless electric energy transmission in an electric field coupling mode; the fractional order parallel type transmitting circuit is composed of a primary side fractional order inductor L_β1And a primary side fractional order compensation capacitor C_α1A resonance circuit formed by parallel connection, wherein the fractional order series receiving circuit is a secondary fractional order inductor L_β2Secondary side fractional order compensation capacitor C_α2And a load R_LThe resonance circuit formed by series connection can realize natural constant current output and improve the output power of the system by adjusting the order of the fractional order element.

Wherein, the order and the inductance value of the primary side fractional order inductor and the secondary side fractional order inductor 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 inductor, the primary side fractional order compensation capacitor, the secondary side fractional order inductor and the secondary side fractional order compensation capacitor are respectively as follows:

as can be seen from the above impedance expression, the fractional order inductor can be equivalent to a series connection of an integer order resistor and an integer order inductor that vary with the operating frequency and the order, and the fractional order compensation capacitor can be equivalent to a series connection of an integer order resistor and an integer order capacitor that vary 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 the imaginary part impedance component of the primary side fractional order capacitor and the secondary side fractional order capacitor is 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 resonant angular frequency of the system depends not only on the inductance value of the fractional order inductor and the capacitance value of the fractional order compensation capacitor, but also on the order of the fractional order inductor and the compensation capacitor, whereas the resonant angular frequency of the conventional integer order electric field coupling wireless power transmission system is determined only by the inductance value and the capacitance value.

Is an electric field energy coupling coefficient, wherein k is the electric field coupling coefficient, and 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 and d is the transmission distance.

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.

A can be obtained according to a coupled mode equation₁And 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 are not only related to the operating angular frequency ω of the power supply and the coupling capacitance C_cAlso relevant is order β of fractional order inductance₁、β₂And fractional order compensation capacitor α₁、α₂Is related to the order of (a). The output power and the transmission efficiency of the traditional electric field coupling wireless power transmission system are only equal to the working angular frequency omega and the coupling capacitor C_cIt is related.

According to the above analysis, the utility model discloses utilize fractional order component to realize parallelly connected-series type electric field coupling wireless power transmission, the dimension of parameter design has been increased, easily system optimization has natural constant current output characteristic, can effectively improve even eliminate load and the influence of distance to system resonant frequency, thereby be favorable to avoiding the emergence of system mistuning, the lowering system requires and the designing requirement to the current level of high frequency current source, and can effectively improve the output of system, be applicable to powerful application scenario, the performance is distinguished from traditional integer order parallelly connected-series compensation type electric field coupling wireless power transmission system completely, 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 (3)

1. A fractional order parallel-series electric field coupling wireless power transmission system is characterized in that: the system comprises a high frequency power current source (I)_s) A fractional order parallel type transmitting circuit, a fractional order series type receiving circuit and a coupling capacitance metal polar plate, the high-frequency power current source (I)_s) Connected in parallel with a fractional order series type transmitting circuit, the fractional order parallel type transmitting circuit and the fractional order series type receiving circuit are connected in parallel through two coupling capacitance metal plates (C)_c1、C_c2) Connecting, and further realizing wireless electric energy transmission in an electric field coupling mode; the fractional order parallel type transmitting circuit is composed of a primary side fractional order inductor (L)_β1) And a primary side fractional order compensation capacitor (C)_α1) A resonance circuit formed by parallel connection, and the fractional order series type receiving circuit is a fractional order inductor (L) with a secondary side_β2) Secondary side fractional order compensation capacitance (C)_α2) And a load (R)_L) The resonance circuit formed by series connection can realize natural constant current output and improve the output power of the system by adjusting the order of the fractional order element.

2. The method of claim 1A fractional order parallel-series electric field coupling wireless power transmission system is characterized in that: the primary side fractional order inductance (L)_β1) And secondary fractional order inductance (L)_β2) The voltage and current differential relation satisfies:

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 inductance,

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

3. The fractional order parallel-series electric field coupled 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:

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 or less, whereinAnd n-1 or 2 denotes a transmitting circuit or a receiving circuit, respectively.

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