Hybrid wireless power transfer system with increased current output and constant output current

Abstract

The application relates to the technical field of wireless power transmission, and particularly discloses a hybrid wireless power transmission system capable of increasing current output and outputting constant current, which utilizes a compensation inductor of a capacitive wireless power transmission system to form an additional inductive coupling channel, can be regarded as series connection of an IPT system and a CPT system in terms of circuit form, sets an electric field coupling mechanism in a laminated mode, and designs a magnetic field coupling mechanism between the electric field coupling mechanisms to form a compact hybrid coupler, and based on modeling of an HWPT system, parameters of constant current output independent of a load are derived. The system can not only realize constant current output at a constant current frequency, but also output double current of a CPT system under the same coupling coefficient. When the coupler is misaligned, the reduction of power transmitted through the inductive channel can be compensated by the increment of power transmitted through the capacitive channel, so that constant current output is realized, and good anti-offset effect is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wireless power transmission, in particular to a hybrid wireless power transmission system with improved current output and constant output current. BACKGROUND

[0002] Common wireless power transmission technologies include inductive power transfer (IPT) and contactless power transfer (CPT). Hybrid wireless power transfer (HWPT) combines IPT technology with CPT technology, using both electric field coupling and magnetic field coupling. This technology takes full advantage of the advantages of magnetic field coupling and electric field coupling while avoiding the disadvantages of these two coupling methods.

[0003] Currently, there is little research on hybrid wireless power transfer technology, and there is a lack of a hybrid wireless power transfer system that can improve current output and maintain constant output current when the load changes, and can also resist coupling mechanism offset. SUMMARY

[0004] The present application provides a hybrid wireless power transmission system that improves current output and maintains constant output current, which solves the technical problem of how to improve the current output of the hybrid wireless power transmission system and maintain constant output current when the load changes, and also resist coupling mechanism offset.

[0005] To solve the above technical problems, the present application provides a hybrid wireless power transmission system that improves current output and maintains constant output current, which includes a DC input source, a high-frequency inverter, a double-sided LC compensation network, a stacked hybrid coupling mechanism, a rectifier filter and an equivalent load R L , the stacked hybrid coupling mechanism includes an electric field coupling mechanism and a magnetic field coupling mechanism, the electric field coupling mechanism is stacked from bottom to top with a first emitter plate P1, a second emitter plate P2, a fourth emitter plate P4, and a third emitter plate P3, the magnetic field coupling mechanism includes a transmitting coil L1 and a receiving coil L2 stacked between the second emitter plate P2 and the fourth emitter plate P4, the transmitting coil L1 is connected in series with the first emitter plate P1, and the receiving coil L2 is connected in series with the third emitter plate P3.

[0006] Preferably, the double-sided LC compensation network includes a primary side LC compensation network and a secondary side LC compensation network.

[0007] The primary side LC compensation network includes the transmitting coil L1 and a primary side compensation capacitor C ex1 , the primary side compensation capacitor Cex1 One end is connected to the common terminal of the transmitting coil L1 and the first transmitting plate P1, and the other end is connected to an output terminal of the high-frequency inverter and the second transmitting plate P2;

[0008] The secondary-side LC compensation network includes the receiving coil L2 and the secondary-side compensation capacitor C. ex2 The secondary-side compensation capacitor C ex2 One end is connected to the common terminal of the receiving coil L2 and the third emitting plate P3, and the other end is connected to an input terminal of the rectifier filter and the fourth emitting plate P4.

[0009] Preferably, the parameter conditions for the system's constant current output are set as follows:

[0010]

[0011] Among them, capacitive X CM =1 / jωC M , resistance to X L1 =jωL1, capacitive reactance X C1 =1 / jωC1, capacitive reactance X C2 =1 / jωC2, ​​equivalent capacitance C1 = C ex1 +C sc1 The equivalent capacitance C2 = C ex2 +C sc2 C sc1 For the self-capacitance of the first emitter plate P1 and the second emitter plate P2, C sc2 For the self-capacitance of the third emitter plate P3 and the fourth emitter plate P4, C M The mutual capacitance of the stacked hybrid coupling mechanism is represented by ω, which is the operating frequency of the system.

[0012] Preferably, the system constant current frequency ω cc Set to:

[0013]

[0014] ω0 represents the self-resonant frequency of the primary-side LC compensation network, which is also the self-resonant frequency of the secondary-side LC compensation network, k c The coupling coefficient of the electric field coupling mechanism is referred to as the electric field coupling coefficient.

[0015] Preferably, if the system output current is set to the target value, then the coupling inductance M of the magnetic field coupling mechanism must be set to satisfy the following:

[0016]

[0017] k c_mis and M misrespectively represent the electric field coupling coefficient and the coupling mutual inductance of the layered hybrid coupling mechanism after coupling offset.

[0018] Preferably, the electric field coupling mechanism is arranged in a symmetrical structure, and the sizes of the outer side plates P1 and P3 of the electric field coupling mechanism are greater than the sizes of the inner side plates P2 and P4.

[0019] Preferably, the transmitting coil L1 and the receiving coil L2 are both Q-type coils with the same size and an inner diameter of l3.

[0020] Preferably, the outer diameter of the Q-type coil is greater than the length and width of the inner side plates P2 and P4.

[0021] Preferably, the outer side plates P1 and P3 are square plates with a side length of l1, and the inner side plates P2 and P4 are square plates with a side length of l2.

[0022] Preferably, the distance between the same side plates of the electric field coupling mechanism is d1, the distance between the same side plates of the layered hybrid coupling mechanism and the coil is d2, and the transmission distance of the layered hybrid coupling mechanism is d.

[0023] The application provides a hybrid wireless power transmission system with improved current output and constant output current, which uses the compensation inductance of a capacitive wireless power transmission system to form an additional inductive coupling channel, and can be seen as a series connection of an IPT system and a CPT system in terms of circuit form. The electric field coupling mechanism is arranged in a layered manner, and the magnetic field coupling mechanism is designed between the electric field coupling mechanisms to form a compact hybrid coupler. Based on the modeling of the HWPT system, the application also derives the parameter settings for constant current output regardless of the load. The system can not only achieve constant current output at a constant frequency, but also output a current that is twice that of a CPT system under the same coupling coefficient. When the coupler is misaligned, the reduction in power transmitted through the inductive channel can be compensated by the increase in power transmitted through the capacitive channel, thereby achieving constant current output and good anti-offset effect. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is an architecture diagram of the hybrid wireless power transmission system with improved current output and constant output current provided by the embodiment of the application;

[0025] Figure 2 is a schematic diagram of the coupling mechanism of the HWPT system provided by the embodiment of the application;

[0026] Figure 3 is an equivalent circuit diagram of the HWPT system provided by the embodiment of the application;

[0027] Figure 4is a typical waveform comparison chart of the bilateral LC compensation CPT system and the HWPT system provided by the embodiment of the present application;

[0028] Figure 5 is a frequency characteristic chart of the CPT system and the HWPT system provided by the embodiment of the present application: (a) transconductance gain (b) input impedance angle;

[0029] Figure 6 is a chart showing the variation of the self-capacitance (a) and mutual-capacitance (b) of the electric field coupling mechanism with x offset;

[0030] Figure 7 is a chart showing the coupling coefficient and the coupling mutual inductance theoretical value under coupling offset provided by the embodiment of the present application;

[0031] Figure 8 is a chart showing the electric field (a) and magnetic field (b) distribution under different coupling offsets provided by the embodiment of the present application;

[0032] Figure 9 is a chart showing the steady-state input and output simulation waveform of the HWPT system when the load is (a) 20 ohms and (b) 40 ohms, and (c) the dynamic simulation waveform chart of load switching;

[0033] Figure 10 is a chart showing the steady-state simulation waveform of the HWPT system when the coupling offset is (a) 0 mm and (b) 100 mm provided by the embodiment of the present application;

[0034] Figure 11 is a chart showing the experimental waveform of the HWPT system when (a) RL = 20 Ω and (b) RL = 40 Ω provided by the embodiment of the present application;

[0035] Figure 12 is a chart showing the experimental waveform of the HWPT system when (a) 0 mm offset and (b) 100 mm offset provided by the embodiment of the present application. DETAILED DESCRIPTION

[0036] The embodiments of the present application will be described in detail below with reference to the accompanying drawings. The embodiments are provided only for illustrative purposes and should not be construed as limiting the present application. The accompanying drawings are only for reference and illustration and do not constitute a limitation on the scope of patent protection of the present application, because many changes can be made to the present application without departing from the spirit and scope thereof.

[0037] The hybrid wireless power transmission system provided by the embodiment of the present application has improved current output and constant output current, and the block diagram thereof is shown in Figure 1 which comprises a DC input source, a high-frequency inverter, a bilateral LC compensation network, a laminated hybrid coupling mechanism, a rectifier filter and an equivalent load R LThe laminated hybrid coupling mechanism includes an electric field coupling mechanism and a magnetic field coupling mechanism, the electric field coupling mechanism is sequentially laminated from bottom to top with a first emitter plate P1, a second emitter plate P2, a fourth emitter plate P4 and a third emitter plate P3, the magnetic field coupling mechanism includes a transmitting coil L1 and a receiving coil L2 which are sequentially laminated between the second emitter plate P2 and the fourth emitter plate P4, the transmitting coil L1 is connected in series with the first emitter plate P1, and the receiving coil L2 is connected in series with the third emitter plate P3.

[0038] The double-sided LC compensation network includes a primary-side LC compensation network and a secondary-side LC compensation network.

[0039] The primary-side LC compensation network includes a transmitting coil L1 and a primary-side compensation capacitor C ex1 One end of the primary-side compensation capacitor C ex1 is connected to a common end of the transmitting coil L1 and the first emitter plate P1, and the other end is connected to an output end of the high-frequency inverter and the second emitter plate P2.

[0040] The secondary-side LC compensation network includes a receiving coil L2 and a secondary-side compensation capacitor C ex2 One end of the secondary-side compensation capacitor C ex2 is connected to a common end of the receiving coil L2 and the third emitter plate P3, and the other end is connected to an input end of the rectifier filter and the fourth emitter plate P4.

[0041] The HWPT system utilizes the compensation inductors of the CPT system to form an additional magnetic field coupling channel. In the magnetic field coupling channel, M represents the mutual inductance between the compensation inductors.

[0042] Compared with a typical CPT system, the coupling mechanism of the HWPT system is composed of an electric field coupling mechanism and a magnetic field coupling mechanism. In order to form a more compact structure, the magnetic field coupling mechanism is placed between the electric field coupling mechanism, thereby forming a compact coupling mechanism as shown in Figure 2 .

[0043] As shown in Figure 2As shown, the electric field coupling mechanism is a typical stacked structure. In order to be consistent in the X-axis and Y-axis, the electric field coupling mechanism is set to be symmetrical, and the magnetic field coupling mechanism adopts a Q-type coil. As shown in FIG. 2, the pole plates P1, P2 and the coil L1 are fixed on one side as the electric energy transmitting end, and the pole plates P3, P4 and the coil L2 are placed on the application as the electric energy receiving end. The electric field coupling mechanism is a loose coupling stacked coupling mechanism, and the magnetic field coupling mechanism is a Q-type coil. In order to obtain a larger cross-coupling capacitance, the size of the outer pole plate of the electric field coupling mechanism is larger than the size of the inner pole plate. In order to reduce the direct area between the coupling pole plate and the coil, the outer diameter of the coil is slightly larger than the size of the inner pole plate. The side length of the P1 and P3 pole plates is l1, the side length of the P2 and P4 pole plates is l2, and the inner diameter of the Q-type coil is l3. The transmission distance between the coupling mechanisms is d, the distance between the pole plates on the same side is d1, and the distance between the pole plates on the same side and the coil is d2.

[0044] Figure 3 The equivalent circuit diagram of the HWPT system is given, jωC M V C1 and jωC M V C2 respectively represent the electric field coupling between the electric energy transmitting end and the receiving end, jωMI o and jωMI in respectively represent the magnetic field coupling between the electric energy transmitting end and the receiving end, C M represents the mutual capacitance of the coupling mechanism, and M represents the mutual inductance of the coupling mechanism. C1 and C2 represent the resonance capacitances of the electric energy transmitting end and the electric energy receiving end, C1=C ex1 +C sc1 , and C2=C ex2 +C sc2 . Among them, C sc1 and C sc2 are the self-capacitances of the electric field coupling mechanism (that is, C sc1 is the self-capacitance of the pole plates P1, P2, and C sc2 is the self-capacitance of the pole plates P3, P4). R e is the equivalent alternating current resistance, R e =8R L / π 2 . V in is the fundamental wave effective value of the inverter output voltage, which can be expressed as:

[0045]

[0046] For the full-bridge rectifier, the input voltage V o and the input current I o can be expressed as:

[0047]

[0048] where V RL , I RL are the voltage and current of the equivalent load R L , respectively.

[0049] According to Kirchhoff's law, the input and output of the HWPT system can be expressed as:

[0050]

[0051] where the inductive reactance X M = jωM, the capacitive reactance X CM = 1 / jωC M , the inductive reactance X L1 = jωL1, the capacitive reactance X C1 = 1 / jωC1, the capacitive reactance X C2 = 1 / jωC2, and ω is the operating frequency of the system.

[0052] According to equation (3), the excitation voltage of the coupling plate can be obtained as:

[0053]

[0054] where m and n are:

[0055]

[0056] In addition, the output voltage of the system can also be expressed as:

[0057]

[0058] According to equations (3)-(6), the output current of the system can be calculated as:

[0059]

[0060] According to equation (7), the condition for the system to output constant current is obtained when the derivative of the output current with respect to the load is zero:

[0061] dI o / dR e = 0 (8)

[0062] In general, the self-resonant frequencies ω1 and ω2 of the power transmitting and receiving end networks are set to be consistent, ω1 = ω2 = ω0. Then, according to equations (7) and (8), the parameter condition for the system to output constant current can be expressed as:

[0063]

[0064] By solving equation (9), the constant current frequency of the system can be calculated and simplified as:

[0065]

[0066] k c The coupling coefficient of the electric field coupling mechanism is referred to as the electric field coupling coefficient.

[0067] Substituting equation (10) into equation (3) can calculate and simplify the input current I in and the output current I o of the system:

[0068]

[0069] As can be seen from equation (11), the output current of the system is independent of the load, and it depends on other system parameters except the load. Compared with the CPT system without magnetic field coupling, the output current of the system is additionally affected by the mutual inductance M. Therefore, the system can also achieve different current gains by adjusting the size of the mutual inductance.

[0070] According to the above analysis, the typical waveforms of the CPT system and the HWPT system with bilateral LC compensation are shown in Figure 4 As can be seen from Figure 4 , the input current of the system is always in phase with the input voltage and leads the output current by 90°. Therefore, in the HWPT system, the induced voltage jωMI in and jωMI o caused by magnetic field coupling is always in phase or opposite with the input voltage and the output voltage. This shows that the additional magnetic coupling channel only changes the size of the output current of the system, but not the phase of the output current of the system. In addition, the system analysis shows that the induced voltage jωMI in is proportional to the load, so the output current of the system can always be independent of the load.

[0071] According to the system parameters listed in Table 1, Figure 5 the conduction gain and the input impedance angle of the two systems CPT system and HWPT system are given with the change of the system frequency. As shown in Figure 5 (a), both the CPT system and the HWPT system can achieve constant current output at constant current frequency, but the output current of the HWPT system is twice that of the CPT system. Similarly, both systems are sensitive to frequency changes at heavy load. As shown in Figure 5 (b), the HWPT system can always achieve ZPA at the constant current frequency point.

[0072] Table 1 System parameters

[0073]

[0074] f0= 2π / ω0 is the frequency corresponding to ω0.

[0075] Based on finite element simulation COMSOL, Figure 6 The variation of self-capacitance and mutual-capacitance with coupling offset is given in Table 2. Since the electric field coupling mechanism is symmetric, the values of two self-capacitances are almost the same under different coupling offsets. As shown in Fig. 2, in the loosely coupled electric field coupling mechanism, the coupling self-capacitance is almost not affected by the coupling offset, while the coupling mutual-capacitance decreases with the increase of the coupling offset. In particular, the coupling mutual-capacitance is negative in some cases, and the electric field mutual coupling presents inductive. Figure 6

[0076] Table 2 Coupling mechanism dimensions

[0077]

[0078] According to the above analysis, when the system parameters are set to be symmetric, the coupling offset of the loosely coupled electric field coupling mechanism has little effect on the self-resonant frequency of the bilateral LC compensation network. Although the electric field coupling coefficient decreases with the increase of the coupling offset, it is always in a very small value (k c <5%), so that the constant current frequency ω cc of the system is almost unchanged. In order to achieve complete tuning, the constant current frequency can be realized by frequency tracking.

[0079] According to the analysis in the last section, the system output current and the coupling coefficient are negatively correlated, and the system output current gradually increases when the coupling coefficient decreases. For the hybrid coupling mechanism, the coupling mutual-capacitance changes with the coupling offset, and the coupling mutual-inductance also changes accordingly. In order to realize the constant system output current under the coupling offset, the mutual-inductance M of the magnetic field coupling mechanism can be set. According to formula (11), the corresponding coupling mutual-inductance changes with the coupling mutual-capacitance when the system output current is set to the target value, which can be expressed as:

[0080]

[0081] where k c_mis and M mis represent the electric field coupling coefficient and the coupling mutual-inductance of the hybrid coupling mechanism after the coupling offset, respectively.

[0082] According to the simulation results, Figure 7 the variation of the electric field coupling coefficient with the coupling offset is shown. In order to realize the constant output current, the corresponding theoretical value of the coupling mutual-inductance is also shown in Figure 7 . Since the output current of the hybrid CPT system is set to one times of the CPT system, when the electric field coupling coefficient is reduced by half, the corresponding coupling mutual-inductance is close to zero, as shown in Figure 7 . Accordingly, when the multiple of the output current is determined, the maximum offset of the coupling mechanism is also determined.​

[0083] According to the above analysis, the size of the coupling self-inductance in the HWPT system does not affect the operation of the system, so the compensation inductance in the HWPT system can be divided into two parts, which can effectively reduce the volume of the magnetic field coupling mechanism. Among them, one part only plays a compensation role, and the other part acts as both a compensation inductance and a coupling inductance. Therefore, for the structure of the magnetic field coupling mechanism, only the mutual inductance thereof needs to meet the mutual inductance value as shown in Figure 7 .

[0084] As is known, the coupling mutual inductance of the magnetic field coupling mechanism depends on its structure, size, transmission distance, and coil turns, etc. Since the transmission distance of the HWPT system is determined, and in order to obtain consistency of the x-axis and y-axis offsets, the coil structure is set to a Q-type coil, so the coupling mutual inductance can be adjusted by adjusting the coil turns and inner diameter. According to the coupling mechanism size listed in Table 1, the self-inductance of the coupling coil is determined to be 8.9 uH.

[0085] According to the data in Table 2, the hybrid coupling mechanism, Figure 8 is determined, and its electric field distribution and magnetic field distribution are shown. From Figure 8 it can be seen that when there is no coupling offset, most of the electric flux and magnetic flux are confined between the coupling plates. When the coupling offset occurs, the leakage electric field is relatively large in the misaligned area, and the magnetic field distribution is relatively reduced compared to the aligned time.

[0086] In order to verify the constant current output characteristics of the system under load changes and coupling offsets, a MATLAB / Simulink simulation model is built according to the system circuit as shown in Figure 1 . Among them, the system parameters are as listed in Table 1. Figure 9 The simulation results of the system under different load resistances are shown, and the waveforms from top to bottom are input voltage v in , input current i in , output voltage v o , and output current i RL .

[0087] As shown in Figure 9 , the input voltage v in and the input current i in of the HWPT system under different load conditions are almost in phase. In order to realize soft switching of the MOSFET switching tube, the compensation inductance of the power transmission end is slightly larger than the theoretical value, so that the system input current is slightly lagging behind the input voltage. Through Figure 9(a), (b) It can be seen that the output voltage of the HWPT system lags behind the input voltage by 90° under different load conditions, which is consistent with the CPT system with double-sided LC compensation. In addition, the output currents of the HWPT system are 2.52 A and 2.46 A when the load resistance is 20 Ω and 40 Ω, respectively. As shown in (c), after the load is switched from 20 Ω to 40 Ω, the input current of the system is doubled, but the output current reaches a steady state after a short overshoot, and the output current remains almost unchanged, which indicates that the system can achieve constant current output under different load conditions. Figure 9

[0088] In addition to the load-independent constant current output, the system can also maintain constant current output characteristics under coupling offset. Since the coupling mechanism of the HWPT system is symmetrical, there is consistency in the x-axis and y-axis, Figure 10 The simulation results of the system under different x-axis coupling offsets are shown, and the load resistance is 30 Ω. The waveforms from top to bottom are input voltage v in , input current i in , output voltage v o and output current i RL . As shown in the figure, when the coupling offset changes from 0 mm to 100 mm, the system output current changes from 2.47 A to 2.53 A. Similarly, the output current of the HWPT system under different coupling offsets is slightly smaller than the output voltage, so the MOSFETs can achieve soft switching. As shown in the figure, the system output voltage lags behind the input voltage by 90 degrees, so the coupling offset has little effect on the working state of the system under loose coupling conditions. In general, the system can achieve constant current output under different coupling offsets.

[0089] To verify the transmission characteristics of the proposed HWPT system, an experimental device consistent with the simulation is established. In order to reduce high-frequency loss, the compensation inductors are made of Litz wire wound on a PVC pipe, and the compensation capacitors are made of multiple mica capacitors connected in series and parallel.

[0090] Similar to the simulation, Figure 11 The experimental waveforms of the HWPT system under different load resistances are shown. As can be seen from the figure, the input current of the HWPT system lags slightly behind the input voltage, which is due to the parameter settings that make the system input impedance slightly inductive, so that the inverter can achieve soft switching. As can be seen from the figure, the output voltage lags behind the input voltage by 90°, and the system working state does not change with the load.

[0091] Figure 12 ​The experimental waveforms of the HWPT system under different coupling offsets are shown. It can be seen from the diagrams that the inverter can still achieve soft switching under different coupling conditions, and the input voltage always leads the output voltage by 90°, so the coupling offset of the system has little effect on the working state of the system. Figure 11 and Figure 12 It is shown that the HWPT system can achieve constant output current under different load resistances and coupling offsets.

[0092] In summary, the embodiment of the present application proposes a hybrid wireless power transmission system which improves current output and achieves constant output current. The system uses the compensation inductance of the capacitive wireless power transmission system to form an additional inductive coupling channel, which can be seen as the series connection of the IPT system and the CPT system in terms of circuit form. The electric field coupling mechanism is arranged in a stacked manner, and the magnetic field coupling mechanism is designed between the electric field coupling mechanisms to form a compact hybrid coupler. Based on the modeling of the HWPT system, the present application also derives the parameter settings for constant current output independent of the load. The system can achieve constant current output at a constant current frequency, and the output current is twice that of the CPT system under the same coupling coefficient. When the coupler is misaligned, the reduction in power transmitted through the inductive channel can be compensated by the increase in power transmitted through the capacitive channel, thereby achieving constant current output and having good anti-offset effect.

[0093] The experimental results show that when the load resistance is switched between 20Ω and 40Ω and the coupling is misaligned by 0-100mm, the output current is almost unchanged, and the input current is in phase with the input voltage. The experimental results also show that the output current of the HWPT system is about twice that of the CPT system with the same capacitive coupler.

[0094] The above embodiment is the preferred embodiment of the present application, but the embodiment of the present application is not limited by the above embodiment, and any change, modification, substitution, combination, simplification made without departing from the spirit and principles of the present application should be an equivalent replacement method, and all are included in the protection scope of the present application.

Claims

1. A hybrid wireless power transfer system that improves current output while maintaining a constant output current, characterized in that, Includes a DC input source, a high-frequency inverter, a bilateral LC compensation network, a cascaded hybrid coupling mechanism, a rectifier filter, and an equivalent load R. L The stacked hybrid coupling mechanism includes an electric field coupling mechanism and a magnetic field coupling mechanism. The electric field coupling mechanism has a first emitting electrode P1, a second emitting electrode P2, a fourth emitting electrode P4, and a third emitting electrode P3 stacked from bottom to top. The magnetic field coupling mechanism includes a transmitting coil L1 and a receiving coil L2 stacked between the second emitting electrode P2 and the fourth emitting electrode P4. The transmitting coil L1 is connected in series with the first emitting electrode P1, and the receiving coil L2 is connected in series with the third emitting electrode P3. The bilateral LC compensation network includes the primary-side LC compensation network and the secondary-side LC compensation network; The primary-side LC compensation network includes the transmitting coil L1 and the primary-side compensation capacitor C. ex1 The primary-side compensation capacitor C ex1 One end is connected to the common terminal of the transmitting coil L1 and the first transmitting plate P1, and the other end is connected to an output terminal of the high-frequency inverter and the second transmitting plate P2; The secondary-side LC compensation network includes the receiving coil L2 and the secondary-side compensation capacitor C. ex2 The secondary-side compensation capacitor C ex2 One end is connected to the common terminal of the receiving coil L2 and the third emitting plate P3, and the other end is connected to an input terminal of the rectifier filter and the fourth emitting plate P4; The parameters for the system's constant current output are set as follows: ， Among them, capacitive , resistance , Rongkang , Rongkang The equivalent capacitance C1 = C ex1 +C sc1 The equivalent capacitance C2 = C ex2 +C sc2 C sc1 For the self-capacitance of the first emitter plate P1 and the second emitter plate P2, C sc2 For the self-capacitance of the third emitter plate P3 and the fourth emitter plate P4, C M This indicates the mutual compatibility of the stacked hybrid coupling mechanism. This refers to the system's operating frequency.

2. The hybrid wireless power transmission system with improved current output and constant output current according to claim 1, characterized in that, System constant current frequency Set to: ， ω0 represents the self-resonant frequency of the primary-side LC compensation network, which is also the self-resonant frequency of the secondary-side LC compensation network. The coupling coefficient of the electric field coupling mechanism is referred to as the electric field coupling coefficient.

3. The hybrid wireless power transfer system with improved current output and constant output current according to claim 2, characterized in that, If the system output current is set to the target value, the coupling inductance M of the magnetic field coupling mechanism must be set to meet the following requirements: ， k c_mis and M mis These represent the electric field coupling coefficient and coupling mutual inductance of the stacked hybrid coupling mechanism after coupling offset, respectively.

4. The hybrid wireless power transfer system with improved current output and constant output current according to any one of claims 1 to 3, characterized in that: The electric field coupling mechanism is configured as a symmetrical structure, and the dimensions of the outer plates P1 and P3 are larger than the dimensions of the inner plates P2 and P4.

5. The hybrid wireless power transfer system with improved current output and constant output current according to claim 4, characterized in that: Both the transmitting coil L1 and the receiving coil L2 are Q-type coils with the same size and an inner diameter of l3.

6. The hybrid wireless power transfer system with improved current output and constant output current according to claim 5, characterized in that: The outer diameter of the Q-type coil is greater than the length and width of the inner plates P2 and P4.

7. The hybrid wireless power transfer system with improved current output and constant output current according to claim 6, characterized in that: The outer electrode plates P1 and P3 are square electrode plates with a side length of l1; the inner electrode plates P2 and P4 are square electrode plates with a side length of l2.

8. The hybrid wireless power transfer system with improved current output and constant output current according to claim 6, characterized in that: The spacing between the same-side plates of the electric field coupling mechanism is set to d1; the spacing between the same-side plates of the stacked hybrid coupling mechanism and the coil is set to d2; the transmission distance of the stacked hybrid coupling mechanism is set to d.

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