CN113541323A - Multi-capacitive energy transmission system with multiple constant current outputs - Google Patents

Abstract

The invention discloses a multi-capacitive energy transmission system with multiple constant current outputs, belonging to the field of wireless energy transmission; a multi-capacitive energy transmission system with multiple constant current outputs comprises relay units #0- # N which are arranged in a linear sequence, and adjacent relay units carry out energy transmission through electric field coupling between a transmitting polar plate and a receiving polar plate; the relay unit #0 comprises two transmitting polar plates, the relay units #1- # N-1 comprise two receiving polar plates and two transmitting polar plates which are vertically arranged, the relay unit # N comprises two receiving polar plates, an equivalent pi model of a capacitive coupler comprising a plurality of relay units is given, a compensation network with split inductors is designed, and constant current output irrelevant to load is realized; the system has the advantages of capability of prolonging the transmission distance, realization of the decoupling of the relay unit, no mutual interference among different loads, simple control flow and low cost.

Description

Multi-capacitive energy transmission system with multiple constant current outputs

Technical Field

The disclosure belongs to the field of wireless energy transmission, and particularly relates to a multi-capacitive energy transmission system with multiple constant current outputs.

Background

The electric field coupling Wireless Power Transfer (CPT) system uses a high-frequency electric field as an energy carrier, high-frequency alternating current acts on a transmitting polar plate, an interactive electric field is formed between the transmitting polar plate and a receiving polar plate, and then displacement current is generated, so that energy transmission between the polar plates is realized. Currently, research on electric field coupled wireless power transfer systems focuses on powering a single load, however, in some cases, it is desirable to power multiple loads simultaneously with a constant current, such as charging a battery in series and powering multiple Light Emitting Diodes (LEDs). The existing multi-load electric field coupling type wireless power transmission system needs to make the distance between the adjacent transmitting electrode plates and the adjacent receiving electrode plates large enough to reduce cross coupling, but the occupied area of the coupler is large. In addition, when the distance between the transmitting plate and the receiving plate of the capacitive coupler is large, the mutual capacitance is small, and thus, energy transmission over a long distance cannot be performed.

In recent years, the present inventors have proposed a structure in which an Inductive Wireless Power Transfer (IPT) system including a plurality of relay units supplies Power to a plurality of loads, which has advantages of being able to extend a transmission distance and eliminating coil coupling in the relay units, but eddy current loss and high cost of the magnetic field coupling Wireless Power Transfer method become important factors restricting the development thereof. In addition, no one has studied an equivalent pi model of a capacitive coupler having a plurality of plates in a conventional multi-load electric field coupling type wireless power transmission system. Therefore, the method has the advantages that the constant current output characteristic is designed, an equivalent model of the capacitive coupler comprising the plurality of relay units is established, the electric field coupling wireless power transmission system comprising the plurality of relay units is adopted to simultaneously supply power to the plurality of loads, the transmission distance is prolonged, and the decoupling of the relay units is realized, so that the method has important significance for the development of the wireless power transmission technology.

Disclosure of Invention

Aiming at the defects of the prior art, the disclosed multi-capacitive energy transmission system with multiple constant current outputs is provided, and the problem that a wireless power transmission system in the prior art cannot carry out remote energy transmission and multi-load power supply is solved.

The purpose of the disclosure can be realized by the following technical scheme:

a multi-capacitive energy transmission system with multiple constant current outputs comprises an inverter and relay units #0- # N which are linearly and sequentially arranged, wherein energy transmission is carried out between adjacent relay units through electric field coupling between a transmitting polar plate and a receiving polar plate;

further, the relay unit #0 includes a transmitting pad P₁ and P₂The relay unit # m (m ═ 1,2, …, N-1) includes a transmitting pad P_4(m-1)+3 and P_4(m-1)+4Receiving polar plate P_4m+1 and P_4m+2The relay unit # N includes a relay unit # N and a receiving pad P_4(N-1)+3 and P_4(N-1)+4(ii) a The input voltage of relay unit #0 is the output voltage of the inverter.

Further, the relay unit #0 includes a compensation inductance L_{1_1} and L_{1_2}Formed L compensation network with split inductor, and external capacitor C_ex,1Wherein the inductance L is compensated_{1_1} and L_{1_2}Is connected with the output of the inverter, and the right side is connected with an external capacitor C_ex,1Connected while an external capacitor C _ex,1And an emitter plate P₁ and P₂In parallel, L_{1_1}＝L_{1_2}。

3. The system of claim 1, wherein the relay unit # m (m-1, 2, …, N-1) comprises a compensation inductor L_{s,m_1}、L_{s,m_2}、L_{f,m+1_1}、L_{f,m+1_2}And a compensation capacitor C_3,m+1Formed LCL compensation network containing split inductor, external capacitor C_ex,2mAnd C_ex,2m+1And a load resistance R_L,mWherein an external capacitance C_ex,2mAnd an emitter plate P_4(m-1)+3 and P_4(m-1)+4Parallel connection, compensation inductance L_{s,m_1} and L_{s,m_2}Left side and external capacitance C_ex,2mConnected to a load resistor R_L,mLeft side and compensation inductance L_{s,m_1}Right side connected to a load resistor R_L,mAnd a compensation inductance L_{s,m_2}Right side of and compensation capacitor C_3,m+1Connected to compensate inductance L_{f,m+1_1}And L_{f,m+1_2}Left side of and compensation capacitor C_3,m+1Connected to compensate inductance L_{f,m+1_1}And L_{f,m+1_2}Right side and external capacitance C_ex,2m+1Connected, external capacitor C_ex,2m+1And a receiving plate P_4m+1 and P_4m+2In parallel, L_{s,m_1}＝L_{s,m_2}，L_{f,m+1_1}＝L_{f,m+1_2}。

Further, the relay unit # N includes a compensation inductance L_{N_1} and L_{N_2}Formed L compensation network containing split inductor, external capacitor C_ex,NAnd a load resistance R_L,NWherein an external capacitance C_ex,NAnd a receiving plate P_4(N-1)+3 and P_4(N-1)+4Parallel connection, compensation inductance L_{N_1} and L_{N_2}Left side and external capacitance C_ex,NConnected to a load resistor R_L,NLeft side of and compensation inductance L_{N_1}Is connected to the right side of the load resistor R_L,NRight side of and compensation inductance L _{N_2}Is connected to the right side of L_{N_1}＝L_{N_2}。

Further, the transmitting pad P in the relay unit #0₁ and P₂On the same plane, the receiving plate P in the repeater unit # m_4(m-1)+3 and P_4(m-1)+4On the same plane, the transmitting plate P in the repeater unit # m_4m+1And P_4m+2On the same plane, the receiving plate P in the repeater unit # N_4(N-1)+3 and P_4(N-1)+4On the same plane, and the receiving plate P in the repeater unit # m_4(m-1)+3、P_4(m-1)+4And an emitter plate P_4m+1、P_4m+2And vertical, all the polar plates are equal in size.

Further, the transmitting pad P in the relay unit #0₁ and P₂Forming a receiving pad P in Port 1, Relay Unit # m_4(m-1)+3 and P_4(m-1)+4Constituting a transmitting plate P in a Port 2m, Relay Unit # m_4m+1 and P_4m+2Constituting a receiving pad P in Port 2m +1, Relay Unit # N_4(N-1)+3 and P_4(N-1)+4Constituting a port 2N; self-capacitance C of port a_port,a(a ═ 1,2, …,2N) is:

wherein ,C_i,jIs a polar plate P_iAnd a polar plate P_jThe coupling capacitance between i, j is 1,2, …,4(N-1) +4, i ≠ j;

mutual capacitance C between any two ports a and b_Ma,b(a, b ≠ 1,2, …,2N, a ≠ b) is:

since the relay unit # m includes the port 2m and the port 2m +1 and the facing areas of the plates are equal to each other, C can be obtained_4m,4m+2＝C_4m-1,4m＝C_4m-1,4m+2＝C_4m,4m-1(iii) substituting the formula (2) to obtain mutual capacitance C in the repeater unit # m_M2m,2m+1The number is 0, so that the decoupling of the relay unit # m in the multi-capacitive energy transmission system with a plurality of constant current outputs is realized;

Sum C of mutual capacitances of port a and the remaining ports_Mport,a(a ═ 1,2, …,2N) is:

further, the transmitting pad P in the repeater unit # m-1_4(m-1)+1、P_4(m-1)+2And receiving plate P in repeater unit # m_4(m-1)+3、P_4(m-1)+4The internal self-capacitance at the left port 2m-1 and the right port 2m of the capacitive coupler m is respectively C_port,2m-1 and C_port,2m(ii) a When the left side port and the right side port are respectively connected with an external capacitor C in parallel_ex,2m-1 and C_ex,2mThen, the equivalent self-capacitance of the left port and the right port is respectively C_s,2m-1 and C_s,2mCan watchShown as follows:

C_s,2m-1＝C_port,2m-1+C_ex,2m-1,C_s,2m＝C_port,2m+C_ex,2m

equivalent input capacitance C looking into the left port of the capacitive coupler m_pri,mComprises the following steps:

the working angular frequency of the inverter is omega₀In order to realize constant current output, the resonance condition is as follows:

compensation capacitor C_3,mComprises the following steps:

when all parasitic resistances of the compensation inductance and the compensation capacitance are ignored, the current flows through the load R_L,mCurrent of (I)_RL,mComprises the following steps:

wherein ,V_in1For the effective value of the fundamental component of the inverter output voltage,

the output current of the first load lags behind the inverter output voltage by 90 DEG I_RL,m＝-I_RL,m-1。

The beneficial effect of this disclosure: the method has the advantages that an equivalent model of the capacitive coupler comprising the relay units is established, the transmission distance is prolonged, the decoupling and constant current output of the relay units are realized, and different loads are not interfered with each other, so that the control flow is simple and the cost is low.

Drawings

In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present disclosure, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

Fig. 1 is a schematic diagram of the overall structure of the transmission system of the present disclosure;

FIG. 2 is a schematic diagram of a capacitive coupler structure of the present disclosure;

FIG. 3 is a schematic diagram of an equivalent pi circuit model of a capacitive coupler of the present disclosure;

FIG. 4 is a simplified equivalent pi circuit model schematic of the present disclosure;

FIG. 5 is a schematic diagram of a multi-capacitive energy transfer system topology with three constant current outputs as used in the present disclosure;

fig. 6 is a schematic structural diagram of a capacitive coupler of a multi-capacitive energy transfer system with three constant current outputs according to the present disclosure;

fig. 7 is a schematic diagram of an equivalent pi circuit model of a capacitive coupler structure of a multi-capacitive energy transmission system with three constant current outputs according to the present disclosure;

FIG. 8 is a simplified equivalent pi circuit model schematic diagram of a multi-capacitive energy transfer system with three constant current outputs according to the present disclosure;

Fig. 9 is a waveform diagram of an output current of a multi-capacitive energy transfer system with three constant current outputs according to the present disclosure (RL,1 ═ RL,2 ═ RL,3 ═ 6 Ω);

fig. 10 is a schematic diagram of waveforms (RL,1 ═ RL,2 ═ RL,3 ═ 11.7 Ω) of output currents of a multi-capacitive energy transfer system with three constant current outputs according to the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are only a part of the embodiments of the present disclosure, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

As shown in fig. 1, the multi-capacitive energy transmission system with multiple constant current outputs comprises 1 inverter and (N +1) relay units; the DC input voltage of the inverter is V_dcThe sequence of all the relay units is as follows: relay unit #0, relay unit #1, and so on, up to relay unit # m, and finally relay unit # N, where m is 1,2, …, N-1; the input voltage of the 1 st relay unit is the output voltage V of the inverter _in(ii) a Relay unit #0 includes a transmitting pad P₁ and P₂Compensating inductance L_{1_1} and L_{1_2}Formed L compensation network with split inductor, and external capacitor C_ex,1Wherein the inductance L is compensated_{1_1} and L_{1_2}Is connected with the output of the inverter, and the right side is connected with an external capacitor C_ex,1Connected while an external capacitor C_ex,1And an emitter plate P₁ and P₂In parallel, L_{1_1}＝L_{1_2}(ii) a The relay unit # m ( m 1,2, …, N-1) includes a transmitting pad P_4(m-1)+3 and P_4(m-1)+4Receiving polar plate P_4m+1 and P_4m+2Compensating inductance L_{s,m_1}、L_{s,m_2}、L_{f,m+1_1}、L_{f,m+1_2}And a compensation capacitor C_3,m+1Formed LCL compensation network containing split inductor, external capacitor C_ex,2mAnd C_ex,2m+1And a load resistance R_L,mWherein an external capacitance C_ex,2mAnd an emitter plate P_4(m-1)+3 and P_4(m-1)+4Parallel connection, compensation inductance L_{s,m_1} and L_{s,m_2}Left side and external capacitance C_ex,2mConnected to a load resistor R_L,mLeft side and compensation inductance L_{s,m_1}Right side connected to a load resistor R_L,mAnd a compensation inductance L_{s,m_2}Right side of and compensation capacitor C_3,m+1Connected to compensate inductance L_{f,m+1_1}And L_{f,m+1_2}Left side of and compensation capacitor C_3,m+1Connected to compensate inductance L_{f,m+1_1}And L_{f,m+1_2}Right side and external capacitance C_ex,2m+1Are connected to each other and outsidePartial capacitance C_ex,2m+1And a receiving plate P_4m+1 and P_4m+2In parallel, L_{s,m_1}＝L_{s,m_2}，L_{f,m+1_1}＝L_{f,m+1_2}(ii) a The relay unit # N includes a receiving pad P_4(N-1)+3 and P_4(N-1)+4Compensating inductance L_{N_1} and L_{N_2}Formed L compensation network containing split inductor, external capacitor C_ex,NAnd a load resistance R_L,NWherein an external capacitance C _ex,NAnd a receiving plate P_4(N-1)+3 and P_4(N-1)+4Parallel connection, compensation inductance L_{N_1} and L_{N_2}Left side and external capacitance C_ex,NConnected to a load resistor R_L,NLeft side of and compensation inductance L_{N_1}Is connected to the right side of the load resistor R_L,NRight side of and compensation inductance L_{N_2}Is connected to the right side of L_{N_1}＝L_{N_2}；

As shown in fig. 2, m is 1,2, …, N-1, the transmitting plate P in relay unit #0₁ and P₂On the same plane, the receiving plate P in the repeater unit # m_4(m-1)+3 and P_4(m-1)+4On the same plane, the transmitting plate P in the repeater unit # m_4m+1And P_4m+2On the same plane, the receiving plate P in the repeater unit # N_4(N-1)+3 and P_4(N-1)+4On the same plane, and the receiving plate P in the repeater unit # m_4(m-1)+3、P_4(m-1)+4And an emitter plate P_4m+1、P_4m+2Vertical, all the polar plates are equal in size; transmitting plate P in Relay Unit #0₁、P₂And receiving plate P in relay unit #1₃、P₄Constituting the transmitting plate P in the capacitive coupler 1, the repeater unit #1₅、P₆And receiving plate P in repeater unit #2₇、P₈Form capacitive coupler 2, and so on, up to transmitting plate P in repeater unit # m-1_4(m-1)+1、P_4(m-1)+2And receiving plate P in repeater unit # m_4(m-1)+3、P_4(m-1)+4Form a capacitive coupler m and finally to the transmitting plate P in the repeater unit # N-1_4(N-1)+1、P_4(N-1)+2And receiving plate P in repeater unit # N_4(N-1)+3、P_4(N-1)+4The capacitive coupler N is formed, and the capacitive coupler 1, the capacitive couplers 2 and …, the capacitive couplers m and … and the capacitive coupler N form a capacitive coupler of a multi-capacitive energy transmission system with multi-constant-current output, wherein two transmitting electrode plates and two receiving electrode plates which form the capacitive coupler are parallel, and the system sequentially passes through the capacitive coupler 1, the capacitive couplers 2 and …, the capacitive couplers m and … and the capacitive coupler N to perform wireless transmission of electric energy; transmitting plate P in Relay Unit #0 ₁ and P₂Forming a receiving pad P in Port 1, Relay Unit # m_4(m-1)+3 and P_4(m-1)+4Constituting a transmitting plate P in a Port 2m, Relay Unit # m_4m+1 and P_4m+2Constituting a receiving pad P in Port 2m +1, Relay Unit # N_4(N-1)+3 and P_4(N-1)+4Constituting a port 2N; self-capacitance C of port a_port,a(a ═ 1,2, …,2N) is:

wherein ,C_i,jIs a polar plate P_iAnd a polar plate P_jThe coupling capacitance between i, j is 1,2, …,4(N-1) +4, i ≠ j;

mutual capacitance C between any two ports a and b_Ma,b(a, b ≠ 1,2, …,2N, a ≠ b) is:

since the relay unit # m includes the port 2m and the port 2m +1 and the facing areas of the plates are equal to each other, C can be obtained_4m,4m+2＝C_4m-1,4m＝C_4m-1,4m+2＝C_4m,4m-1(iii) substituting the formula (2) to obtain mutual capacitance C in the repeater unit # m_M2m,2m+1The number is 0, so that the decoupling of the relay unit # m in the multi-capacitive energy transmission system with multiple constant current outputs is realized;

sum C of mutual capacitances of port a and the remaining ports_Mport,a(a ═ 1,2, …,2N) is:

therefore, an equivalent pi model of a capacitive coupler of a multi-capacitive energy transmission system with multiple constant current outputs is shown in fig. 3: the self-capacitance of all the ports can be obtained by the formula (1), the mutual capacitance of any two ports can be obtained by the formula (2), and the sum of the mutual capacitance of any one port and the mutual capacitance of the rest of the ports can be obtained by the formula (3).

The simplified equivalent pi model of the multi-capacitive energy transmission system with multiple constant current outputs is shown in fig. 4, since the mutual capacitance between any two non-adjacent ports is very small, the mutual capacitance can be ignored, and since the mutual capacitance in the relay unit # m is 0, when designing a compensation network of the multi-capacitive energy transmission system with multiple constant current outputs, only the mutual capacitance C of the capacitive coupler m needs to be considered _M2m-1,2mAnd can be obtained by the formula (2), the internal self-capacitance at the left port 2m-1 and the right port 2m of the capacitive coupler m is C_port,2m-1 and C_port,2mCan be obtained by the formula (1); when the left side port and the right side port are respectively connected with an external capacitor C in parallel_ex,2m-1 and C_ex,2mThen, the equivalent self-capacitance of the left port and the right port is respectively C_s,2m-1 and C_s,2mIt can be expressed as:

C_s,2m-1＝C_port,2m-1+C_ex,2m-1,C_s,2m＝C_port,2m+C_ex,2m (4)

equivalent input capacitance C looking into the left port of the capacitive coupler m_pri,mComprises the following steps:

the working angular frequency of the inverter is omega₀In order to realize constant current output, the resonance condition is as follows:

compensation capacitor C_3,mComprises the following steps:

when all parasitic resistances of the compensation inductance and the compensation capacitance are ignored, the current flows through the load R_L,mCurrent of (I)_RL,mComprises the following steps:

wherein ,V_in1For an effective value of the fundamental component of the inverter output voltage, since the inverter operates in a complementary mode, it can be expressed as

It can be seen that the output current of the first load lags behind the inverter output voltage by 90 °, and by substituting equation (7) for equation (8), I can be obtained_RL,m＝-I_RL,m-1Therefore, in the multi-load electric field coupling type wireless power transmission system with the multiple relay units, the current flowing through two adjacent loads has the same amplitude, i.e. | I_RL,1|＝|I_RL,2|,…＝|I_RL,NAnd independent of the load resistance, the phase difference of the current flowing through two adjacent loads is 180 degrees, so that a multi-capacitive energy transmission system with multiple constant current outputs is realized.

The following description will specifically take a multi-capacitive energy transmission system with three constant current outputs as an example.

A multi-capacitive energy transfer system with multiple constant current outputs as shown in fig. 5, comprising 1 inverter and 4 relay units; the DC input voltage of the inverter is V_dcThe sequence of all the relay units is as follows: relay unit #0, relay unit #1, relay unit #2, and relay unit # 3; the input voltage of the 1 st relay unit is the output voltage V of the inverter_in；

Relay unit #0 includesEmitting electrode plate P₁ and P₂Compensating inductance L_{1_1} and L_{1_2}Formed L compensation network with split inductor, and external capacitor C_ex,1Wherein the inductance L is compensated_{1_1} and L_{1_2}Is connected with the output of the inverter, and the right side is connected with an external capacitor C_ex,1Connected while an external capacitor C_ex,1And an emitter plate P₁ and P₂In parallel, L_{1_1}＝L_{1_2}；

Relay unit #1 includes a transmitting pad P₃ and P₄Receiving polar plate P₅ and P₆Compensating inductance L_{s,1_1}、L_{s,1_2}、L_{f,2_1}、L_{f,2_2}And a compensation capacitor C_3,2Formed LCL compensation network containing split inductor, external capacitor C_ex,2And C_ex,3And a load resistance R_L,1Wherein an external capacitance C_ex,2And an emitter plate P₃ and P₄Connected in parallel, compensating inductance L_{s,1_1} and L_{s,1_2}Left side and external capacitance C_ex,2Connected to a load resistor R_L,1Left side and compensation inductance L _{s,1_1}Right side connected to a load resistor R_L,1And a compensation inductance L_{s,1_2}Right side of and compensation capacitor C_3,2Connected to compensate inductance L_{f,2_1}And L_{f,2_2}Left side of and compensation capacitor C_3,2Connected to compensate inductance L_{f,2_1}And L_{f,2_2}Right side and external capacitance C_ex,3Connected, external capacitor C_ex,3And a receiving plate P₅ and P₆In parallel, L_{s,1_1}＝L_{s,1_2}，L_{f,2_1}＝L_{f,2_2}；

Relay unit #2 includes a transmitting pad P₇ and P₈Receiving polar plate P₉ and P₁₀Compensating inductance L_{s,2_1}、L_{s,2_2}、L_{f,3_1}、L_{f,3_2}And a compensation capacitor C_3,3Formed LCL compensation network containing split inductor, external capacitor C_ex,4And C_ex,5And a load resistance R_L,2Wherein an external capacitance C_ex,4And an emitter plate P₇ and P₈Are connected in parallel and supplementedInductance L_{s,2_1} and L_{s,2_2}Left side and external capacitance C_ex,4Connected to a load resistor R_L,2Left side and compensation inductance L_{s,2_1}Right side connected to a load resistor R_L,2And a compensation inductance L_{s,2_2}Right side of and compensation capacitor C_3,3Connected to compensate inductance L_{f,3_1}And L_{f,3_2}Left side of and compensation capacitor C_3,3Connected to compensate inductance L_{f,3_1}And L_{f,3_2}Right side and external capacitance C_ex,5Connected, external capacitor C_ex,5And a receiving plate P₉ and P₁₀Are connected in parallel, L_{s,3_1}＝L_{s,3_2}，L_{f,4_1}＝L_{f,4_2}；

Relay unit #4 includes a receiving pad P₁₁ and P₁₂Compensating inductance L_{N_1} and L_{N_2}Formed L compensation network containing split inductor, external capacitor C_ex,6And a load resistance R_L,3Wherein an external capacitance C_ex,6And a receiving plate P₁₁ and P₁₂Parallel connection, compensation inductance L_{N_1} and L_{N_2}Left side and external capacitance C_ex,6Connected to a load resistor R_L,3Left side of and compensation inductance L_{N_1}Is connected to the right side of the load resistor R_L,3Right side of and compensation inductance L_{N_2}Is connected to the right side of L_{N_1}＝L_{N_2}；

As shown in FIG. 6, the capacitive coupler of the multi-capacitive energy transmission system with three constant current outputs comprises a pole plate P₁、P₂、P₃、P₄、P₅、P₆、P₇、P₈、P₉、P₁₀、P₁₁ and P₁₂All plates are equal in size, the transmitting plate P in the relay unit #0₁ and P₂On the same plane, the receiving plate P in the repeater unit #1₃ and P₄On the same plane, the transmitting plate P in the repeater unit #1₅And P₆On the same plane, the receiving plate P in the repeater unit #2₇ and P₈On the same plane, the transmitting plate P in the repeater unit #2₉ and P₁₀In the same timeOne plane, the receiving plate P in the repeater unit #3₁₁And P₁₂On the same plane, and the receiving plate P in the relay unit #1₃、P₄And an emitter plate P₅、P₆Vertical, receiving pad P in repeater Unit #2₇、P₈And an emitter plate P₉、P₁₀Vertically; transmitting plate P in Relay Unit #0₁、P₂And receiving plate P in relay unit #1₃ and P₄Constituting the transmitting plate P in the capacitive coupler 1, the repeater unit #1₅、P₆And the receiving plate P in the repeater unit #2₇、P₈Constituting the transmitting plate P in the capacitive coupler 2, the repeater unit #2₉、P₁₀And the receiving plate P in the repeater unit #3 ₁₁ and P₁₂The capacitive coupler 3 is formed, and the capacitive coupler 1, the capacitive coupler 2 and the capacitive coupler 3 form a capacitive coupler of a multi-capacitive energy transmission system with multiple constant current outputs; the system carries out wireless transmission of electric energy through the capacitive coupler 1, the capacitive coupler 2 and the capacitive coupler 3 in sequence; transmitting plate P in Relay Unit #0₁ and P₂The receiving plate P in the repeater unit #1 constituting the port 1₃ and P₄Constituting the transmitting plate P in Port 2, Relay Unit #1₅ and P₆Constituting a receiving pad P in Port 3, Relay Unit #1₇ and P₈Constituting the transmitting pad P in Port 4, Relay Unit #2₉ and P₁₀Constituting a receiving pad P in Port 5, Relay Unit #3₁₁ and P₁₂Constituting the port 6, the self-capacitance C of each port_port,a(a ═ 1,2, …,6) is:

wherein ,C_i,jIs a polar plate P_iAnd a polar plate P_jThe coupling capacitance between i, j ≠ j 1,2, …,12, i ≠ j.

Mutual capacitance C between any two ports a and b_Ma,b(a, b ≠ 1,2, …,6, a ≠ b) is:

the relay unit #1 includes ports 2 and 3, and the areas facing the plates are equal to each other, so that C can be obtained_4,6＝C_3,4＝C_3,6＝C_4,3By substituting equation (2), mutual capacitance C in relay unit #1 can be obtained_M2,3Is 0; the relay unit #2 includes ports 4 and 5, and the areas facing the plates are equal to each other, so that C can be obtained _8,10＝C_7,8＝C_7,10＝C_8,7By substituting equation (2), mutual capacitance C in relay unit #2 can be obtained_M4,5Is 0; thereby achieving the decoupling of the relay unit #1 and the relay unit # 2.

Sum C of mutual capacitances of port a and the remaining ports_Mport,a(a ═ 1,2, …,6) is:

therefore, an equivalent pi model of a capacitive coupler of a multi-capacitive energy transmission system with three constant current outputs is shown in fig. 7: the self-capacitance of all the ports can be obtained by the formula (1), the mutual capacitance of any two ports can be obtained by the formula (2), and the sum of the mutual capacitance of any one port and the mutual capacitance of the rest of the ports can be obtained by the formula (3).

A simplified equivalent pi model of a multi-capacitive energy transfer system with three constant current outputs is shown in fig. 8, where C is the minimum mutual capacitance between any two non-adjacent ports_M1,3、C_M1,4、C_M1,5、C_M1,6、C_M2,4、C_M2,5、C_M2,6、C_M3,5、C_M3,6 and C_M4,6Can be ignored, and due to mutual capacitance C in the relay unit #1_M2,₃0, mutual capacitance C in Relay Unit #2_M4,5Is 0, therefore, when designing a compensation network of a multi-capacitive energy transmission system with four constant current outputs, only the mutual capacitance of the capacitive coupler 1 needs to be consideredIs C_M1,2The mutual capacitance of the capacitive coupler 2 is C_M3,4And mutual capacitance C of the capacitive coupler 3_M5,6(ii) a The internal self-capacitance at the left port 1 and the right port 2 of the capacitive coupler 1 is C _port,1 and C_port,2Can be obtained by the formula (1); when the left side port and the right side port are respectively connected with an external capacitor C in parallel_ex,1 and C_ex,2Then, the equivalent self-capacitance of the left port and the right port is respectively C_s,1 and C_s,2(ii) a The internal self-capacitance at the left port 3 and the right port 4 of the capacitive coupler 2 is C_port,3 and C_port,4Can be obtained by the formula (1); when the left side port and the right side port are respectively connected with an external capacitor C in parallel_ex,3 and C_ex,4Then, the equivalent self-capacitance of the left port and the right port is respectively C_s,3 and C_s,4(ii) a The internal self-capacitance at the left port 5 and the right port 6 of the capacitive coupler 3 is C_port,5 and C_port,6Can be obtained by the formula (1); when the left side port and the right side port are respectively connected with an external capacitor C in parallel_ex,5 and C_ex,6Then, the equivalent self-capacitance of the left port and the right port is respectively C_s,5 and C_s,6(ii) a The equivalent self-capacitance of the capacitive couplers 1, 2 and 3 can be expressed as:

the equivalent input capacitance as seen from the left port of the capacitive coupler 1 is C_pri,1The equivalent input capacitance as seen from the left port of the capacitive coupler 2 is C_pri,2The equivalent input capacitance as seen from the left port of the capacitive coupler 3 is C_pri,3It can be expressed as:

the working angular frequency of the inverter is omega₀In order to realize constant current output, the resonance condition is as follows:

Compensation capacitor C_3,2 and C_3,3Comprises the following steps:

when all parasitic resistances of the compensation inductance and the compensation capacitance are ignored, the current flows through the load R_L,1Has a current of I_RL,1Through a load R_L,2Has a current of I_RL,2Through a load R_L,3Has a current of I_RL,3It can be expressed as:

wherein ,V_in1For an effective value of the fundamental component of the inverter output voltage, since the inverter operates in a complementary mode, it can be expressed as

It can be seen that the output current of the first load lags behind the inverter output voltage by 90 °, and by substituting equation (7) for equation (8), I can be obtained_RL,1＝-I_RL,2＝I_RL,3Therefore, in the multi-load electric field coupling type wireless power transmission system with the multiple relay units, the current flowing through two adjacent loads has the same amplitude, i.e. | I_RL,1|＝|I_RL,2|,＝|I_RL,3And independent of load resistance, the phase difference of the current flowing through two adjacent loads is 180 degrees, so that a multi-capacitive energy transmission system with three constant current outputs is realized.

And (3) analyzing an experimental result:

FIG. 9 shows the load resistance R_L,1＝R_L,2＝R_L,3At 6 Ω, the waveform of the output current of the multi-capacitive energy transfer system with three constant current outputs is seen to lag behind that of the first loadThe inverter outputs voltage of 90 degrees, the effective value of the output current of the first load is 0.748A, the effective value of the output current of the second load is 0.741A, the effective value of the output current of the third load is 0.736A, and it can be seen that the currents of the three loads are approximately equal, and the phase difference of the currents of the adjacent loads is 180 degrees; FIG. 10 is a graph showing the load resistance R _L,1＝R_L,2＝R_L,3When the waveform of the output current of the multi-capacity energy transmission system including three constant current outputs is 11.7 Ω, it can be seen that the output current of the first load lags behind the inverter output voltage by 90 °, the effective value of the output current of the first load is 0.746A, the effective value of the output current of the second load is 0.729A, and the effective value of the output current of the third load is 0.717A, and it can be seen that the currents of the three loads are approximately equal and the phase difference between the currents of the adjacent loads is 180 °. In fig. 9 and 10, the small drop in current of the latter load relative to the former load is due to the internal resistance in the compensation circuit. The experimental results show that the multi-capacitive energy transmission system with three constant current outputs realizes the constant current output of three loads and load power decoupling.

It can be seen from the above embodiments that the multi-capacitive energy transmission system with multiple constant current outputs provided by the present invention can achieve constant current output and load power decoupling.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed.

Claims (7)

1. A multi-capacitive energy transmission system with multiple constant current outputs is characterized in that the transmission system comprises an inverter and relay units #0- # N which are linearly and sequentially arranged, and energy transmission is carried out between adjacent relay units through electric field coupling between a transmitting polar plate and a receiving polar plate;

relay unit #0 includes a transmitting pad P₁ and P₂The relay unit # m (m ═ 1,2, …, N-1) includes a transmitting pad P_4(m-1)+3 and P_4(m-1)+4Receiving polar plate P_4m+1 and P_4m+2The relay unit # N includes a relay unit # N and a receiving pad P_4(N-1)+3 and P_4(N-1)+4(ii) a The input voltage of relay unit #0 is the output voltage of the inverter.

2. The system of claim 1, wherein the repeater unit #0 comprises a compensation inductor L _{1_1} and L_{1_2}Formed L compensation network with split inductor, and external capacitor C_ex,1Wherein the inductance L is compensated_{1_1} and L_{1_2}Is connected with the output of the inverter, and the right side is connected with an external capacitor C_ex,1Connected while an external capacitor C_ex,1And an emitter plate P₁ and P₂In parallel, L_{1_1}＝L_{1_2}。

3. The system of claim 1, wherein the relay unit # m (m-1, 2, …, N-1) comprises a compensation inductor L_{s,m_1}、L_{s,m_2}、L_{f,m+1_1}、L_{f,m+1_2}And a compensation capacitor C_3,m+1Formed LCL compensation network containing split inductor, external capacitor C_ex,2mAnd C_ex,2m+1And a load resistance R_L,mWherein an external capacitance C_ex,2mAnd an emitter plate P_4(m-1)+3 and P_4(m-1)+4Parallel connection, compensation inductance L_{s,m_1} and L_{s,m_2}Left side and external capacitance C_ex,2mConnected to a load resistor R_L,mLeft side and compensation inductance L_{s,m_1}Right side connected to a load resistor R_L,mAnd a compensation inductance L_{s,m_2}Right side of and compensation capacitor C₃,_m+1Connected to compensate inductance L_{f,m+1_1}And L_{f,m+1_2}Left side of and compensation capacitor C_3,m+1Connected to compensate inductance L_{f,m+1_1}And L_{f,m+1_2}Right side and external capacitance C_ex,2m+1Connected, external capacitor C_ex,2m+1And a receiving plate P_4m+1 and P_4m+2In parallel, L_{s,m_1}＝L_{s,m_2}，L_{f,m+1_1}＝L_{f,m+1_2}。

4. The multi-capacitive energy transfer system with multiple constant current outputs of claim 1, wherein the relay unit # N comprises a compensation inductor L_{N_1} and L_{N_2}Formed L compensation network containing split inductor, external capacitor C_ex,NAnd a load resistance R_L,NWherein an external capacitance C_ex,NAnd a receiving plate P_4(N-1)+3 and P_4(N-1)+4Parallel connection, compensation inductance L_{N_1} and L_{N_2}Left side and external capacitance C_ex,NConnected to a load resistor R_L,NLeft side of and compensation inductance L_{N_1}Is connected to the right side of the load resistor R_L,NRight side of and compensation inductance L_{N_2}Is connected to the right side of L_{N_1}＝L_{N_2}。

5. The system of claim 1, wherein the transmitting plate P in the repeater unit #0 is a multi-capacitor with multiple constant current outputs₁ and P₂On the same plane, the receiving plate P in the repeater unit # m_4(m-1)+3 and P_4(m-1)+4On the same plane, the transmitting plate P in the repeater unit # m_4m+1And P_4m+2On the same plane, the receiving plate P in the repeater unit # N_4(N-1)+3 and P_4(N-1)+4On the same plane, and the receiving plate P in the repeater unit # m_4(m-1)+3、P_4(m-1)+4And an emitter plate P_4m+1、P_4m+2And vertical, all the polar plates are equal in size.

6. The system of claim 5, wherein the transmitting plate P of the relay #0 is a multi-constant current output₁ and P₂Forming a receiving pad P in Port 1, Relay Unit # m_4(m-1)+3 and P_4(m-1)+4Constituting a transmitting plate P in a Port 2m, Relay Unit # m_4m+1 and P_4m+2Constituting a receiving pad P in Port 2m +1, Relay Unit # N _4(N-1)+3 and P_4(N-1)+4Constituting a port 2N; self-capacitance C of port a_port,a(a ═ 1,2, …,2N) is:

wherein ,C_i,jIs a polar plate P_iAnd a polar plate P_jThe coupling capacitance between i, j is 1,2, …,4(N-1) +4,

i≠j；

mutual capacitance C between any two ports a and b_Ma,b(a, b ≠ 1,2, …,2N, a ≠ b) is:

since the relay unit # m includes the port 2m and the port 2m +1 and the facing areas of the plates are equal to each other, C can be obtained_4m,4m+2＝C_4m-1,4m＝C_4m-1,4m+2＝C_4m,4m-1(iii) substituting the formula (2) to obtain mutual capacitance C in the repeater unit # m_M2m,2m+1The number is 0, so that the decoupling of the relay unit # m in the multi-capacitive energy transmission system with a plurality of constant current outputs is realized;

sum C of mutual capacitances of port a and the remaining ports_Mport,a(a＝1,2,…And 2N) is:

7. the multi-capacitive energy transfer system with multiple constant current outputs as claimed in claim 6, wherein the transmitting plate P in the relay unit # m-1_4(m-1)+1、P_4(m-1)+2And receiving plate P in repeater unit # m_4(m-1)+3、P_4(m-1)+4The internal self-capacitance at the left port 2m-1 and the right port 2m of the capacitive coupler m is respectively C_port,2m-1 and C_port,2m(ii) a When the left side port and the right side port are respectively connected with an external capacitor C in parallel_ex,2m-1 and C_ex,2mThen, the equivalent self-capacitance of the left port and the right port is respectively C_s,2m-1 and C_s,2mIt can be expressed as:

C_s,2m-1＝C_port,2m-1+C_ex,2m-1,C_s,2m＝C_port,2m+C_ex,2m

equivalent input capacitance C looking into the left port of the capacitive coupler m _pri,mComprises the following steps:

the working angular frequency of the inverter is omega₀In order to realize constant current output, the resonance condition is as follows:

compensation capacitor C_3,mComprises the following steps:

when all parasitic resistances of the compensation inductance and the compensation capacitance are ignored, the current flows through the load R_L,mCurrent of (I)_RL,mComprises the following steps:

wherein ,V_in1For the effective value of the fundamental component of the inverter output voltage,

the output current of the first load lags behind the inverter output voltage by 90 DEG I_RL,m＝-I_RL,m-1。

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