Power fluctuation suppression system applied to dynamic wireless power transmission

Abstract

The invention provides a power fluctuation suppression system applied to dynamic wireless power transmission, and the system comprises a direct current inversion module which is used for converting a direct current into a high-frequency alternating current and controlling the start and stop of a transmitting coil; the compensation topology comprises a primary side S compensation network and a secondary side S compensation network which are respectively connected with the transmitting end and the receiving end; the composite solenoid transmitting coil is composed of a plurality of transmitting units which are laid alternately, each transmitting unit comprises three sets of solenoid coils which are connected in series, and the current directions of the coils are the same. The double-solenoid receiving coil is formed by symmetrically winding two groups of solenoid coils which are connected in series on a ferrite; and the rectification module is used for converting the received high-frequency alternating current into direct current and outputting the direct current. The beneficial effects of the invention are that through the specific structure and turn number adjustment of the composite solenoid transmitting coil, the problem of resonance circuit instability caused by cross coupling of multiple transmitting coils is fundamentally solved, and the design complexity of compensation parameters is significantly reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless power transmission, and in particular relates to a power fluctuation suppression system applied to dynamic wireless power transmission. Background Art

[0002] The current mainstream segmented transmitting coil structure has inherent defects: when the coil spacing is too close, the cross-coupling effect between adjacent transmitting units will significantly increase the complexity of the resonant circuit, resulting in unstable transmission characteristics; and when the spacing is too large, the receiving end will produce severe DC voltage / current fluctuations, which not only reduces charging efficiency but may also damage the battery.

[0003] Existing improvement solutions, such as optimizing coil shape or adding closed-loop control, are unable to eliminate cross-coupling while maintaining the continuity of power transmission. An innovative solution that can simultaneously address structural coupling and dynamic power fluctuations is urgently needed. Summary of the Invention

[0004] In view of this, the present invention aims to provide a power fluctuation suppression system for dynamic wireless power transmission, so as to at least solve one of the problems in the background art.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] This solution discloses a power fluctuation suppression system for dynamic wireless power transmission, comprising:

[0007] DC inverter module, used to convert DC power into high-frequency AC power and control the start and stop of the transmitting coil;

[0008] The compensation topology includes a primary-side S compensation network and a secondary-side S compensation network, connected to the transmitter and receiver respectively;

[0009] The composite solenoid transmitting coil is composed of multiple alternately laid transmitting units. Each transmitting unit contains three sets of solenoid coils connected in series, and the current direction of each coil is the same.

[0010] The double solenoid receiving coil is composed of two sets of series-connected solenoid coils symmetrically wound on ferrite;

[0011] Rectifier module, used to convert the received high-frequency AC power into DC power output;

[0012] in,

[0013] The composite solenoid transmitting coil achieves natural decoupling by adjusting the number of coil turns so that the mutual inductance between adjacent transmitting units satisfies M1+M2=0;

[0014] The axially symmetric magnetic field distribution of the dual solenoid receiving coil suppresses fluctuations in the coupling coefficient when the power receiver moves.

[0015] Furthermore, each transmitting unit of the composite solenoid transmitting coil comprises three sets of solenoid coils L connected in series. n1 , L n2 , L n3 ,in:

[0016] L n1 , L n2 Wound on the nth ferrite, L n3 Wrapped around the n+1th section of ferrite, the current directions of each coil are the same.

[0017] Furthermore, in the composite solenoid transmitting coil, L n1 , L n2 The reverse coupling mutual inductance M1<0, L n3 The generated forward coupling mutual inductance M2>0, and M1 and M2 are offset by adjusting the number of turns.

[0018] Furthermore, the primary side S compensation network includes a first compensation capacitor C1 and a second compensation capacitor C2 connected in parallel, corresponding to two sets of transmitting coils respectively; the secondary side S compensation network includes a secondary side compensation capacitor C s ; Compensation parameters meet the resonance conditions:

[0019]

[0020] Where: ω is the system resonant angular frequency, L 13 , L 14 is the equivalent inductance of the first set of transmitting coils, L 23 , L 24 is the equivalent inductance of the second group of transmitting coils, and Ls is the inductance of the receiving coil.

[0021] Furthermore, the DC inverter module includes a DC voltage source and a full-bridge inverter circuit composed of four MOSFETs, and the rectifier module is a single-phase bridge rectifier circuit including four rectifier diodes and a filter capacitor.

[0022] Furthermore, the longitudinally symmetrical structure of the dual-solenoid receiving coil enables the mutual inductance change rate to be lower than that of a planar coil structure when the dual-solenoid receiving coil moves in the laying direction of the transmitting coil.

[0023] Furthermore, the two groups of solenoid coils of the dual-solenoid receiving coil are wound around the same ferrite in an axially symmetrical manner, and the winding axis lines of the two groups of coils are parallel to the laying direction of the transmitting coil.

[0024] Furthermore, in the primary side S compensation network:

[0025] The first compensation capacitor C1 is connected in parallel to the equivalent inductance L of the first group of transmitting coils 14 , L13 ;

[0026] The second compensation capacitor C2 is connected in parallel to the equivalent inductance L of the second group of transmitting coils 24 , L 23 .

[0027] Furthermore, the system uses a position detection sensor to determine the position of the mobile power receiver in real time and controls the DC inverter module to start and stop the corresponding transmitting unit.

[0028] Furthermore, when the receiving coil moves in the arrangement direction of the transmitting coils, the mutual inductance value of the composite solenoid transmitting coil and the dual solenoid receiving coil presents a smooth and stable waveform.

[0029] Compared with the prior art, the power fluctuation suppression system for dynamic wireless power transmission described in the present invention has the following beneficial effects:

[0030] (1) The power fluctuation suppression system for dynamic wireless power transmission described in the present invention achieves a total mutual inductance M1+M2=0 between adjacent transmitting units through the specific structure and turn adjustment of the composite solenoid transmitting coil, fundamentally solving the problem of resonant circuit instability caused by cross-coupling of multiple transmitting coils and significantly reducing the complexity of compensation parameter design;

[0031] (2) The power fluctuation suppression system for dynamic wireless power transmission described in the present invention uses a dual-solenoid receiving coil with axially symmetrical magnetic fields to make the coupling coefficient change gradually smooth during the longitudinal movement of the power receiver, ensuring continuous and stable output power and avoiding the risk of charging interruption and battery damage caused by severe fluctuations in DC voltage / current;

[0032] (3) In a power fluctuation suppression system for dynamic wireless power transmission described in the present invention, the composite solenoid structure achieves natural decoupling through mutual inductance self-cancellation, eliminating the hardware requirements of active filters or complex compensation networks in the prior art, reducing manufacturing costs and improving system reliability;

[0033] (4) The power fluctuation suppression system for dynamic wireless power transmission described in the present invention has a collaborative coupling design of the composite solenoid coil at the transmitting end and the dual solenoid coil at the receiving end, which maintains efficient energy transfer while achieving decoupling, thereby ensuring the overall transmission efficiency of the dynamic wireless charging system. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0035] Figure 1 It is a system circuit structure diagram of the present invention;

[0036] Figure 2 It is a schematic diagram of the structure of the composite solenoid transmitting coil and the double solenoid receiving coil of the present invention;

[0037] Figure 3 It is a simplified schematic diagram of the cross-coupling of the transmitting coil in the present invention;

[0038] Figure 4 It is the decoupling simplified topological equivalent circuit diagram of the present invention;

[0039] Figure 5 This is a mutual inductance waveform diagram during the movement of the power receiver of the present invention. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0041] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0042] Wireless charging is widely used in various electrical devices due to its convenience, and dynamic wireless power transfer technology (DWPT) has achieved the function of charging on the move. However, existing technologies still have problems such as large output power fluctuations and insufficient transmission stability, which may lead to charging interruptions or reduced efficiency, and even affect battery life. In addition, cross-coupling between transmitting units is inevitably introduced into the resonant circuit, which not only increases the complexity of compensation parameter design and system analysis, but also leads to uncertainty in the transmission characteristics of the dynamic wireless charging system. The present invention can effectively solve the above problems and realize high-performance dynamic wireless charging.

[0043] In existing technologies, dynamic wireless charging systems primarily employ long rails and segmented rails. To balance electromagnetic compatibility and charging efficiency, a segmented transmitting coil array layout is currently widely adopted. However, existing technologies still face key challenges: when transmitting coils are closely spaced, cross-coupling effects between adjacent coils significantly increase the complexity of system analysis and lead to unstable transmission characteristics. Excessive spacing can cause drastic fluctuations in the DC output voltage or current at the receiving end, impacting charging quality and potentially negatively impacting battery life.

[0044] The main problem to be solved by this invention is to address the range anxiety of existing mobile power receivers, the mutual inductance cross-coupling between multiple power transmitting coils in DWPT systems, and the power fluctuations that occur at the receiving end during the movement of the power receiver. A composite solenoid coupling structure is designed. Each transmitting coil contains three sets of solenoid coils connected in series. The mutual inductance of two coils with the adjacent coil is offset by the mutual inductance of another coil with the adjacent coil, achieving decoupling. This structure eliminates the need for additional compensation devices at the transmitting end to mitigate the cross-coupling effects between the power transmitting coils, reducing costs while simplifying the design of compensation parameters. The receiving end uses a dual-solenoid coupling structure, which enables efficient coupling between the transmitting and receiving coils, significantly improving transmission performance and suppressing output power fluctuations.

[0045] The technical solution adopted by the present invention is: a power fluctuation suppression system applied to dynamic wireless power transmission.

[0046] The system comprises: (1) a DC inverter module; (2) a compensation topology; (3) a composite solenoid transmitting coil; (4) a dual solenoid receiving coil; and (5) a rectifier module. The dynamic wireless power transmission system uses an alternating magnetic field as a medium for energy transfer between the receiving and transmitting coils, and starts and stops the transmitting coil at the corresponding position in real time according to the position of the mobile power receiver. The DC inverter module (1) converts DC power into high-frequency AC power, generates a high-frequency electromagnetic field in space, and controls the start and stop of the corresponding transmitting coil. The inverted high-frequency AC power resonates with the primary side composite solenoid transmitting coil (3) through the primary side compensation topology (2), and transfers energy to the dual solenoid receiving coil (4) based on the near-field resonant coupling principle. The secondary side compensation topology (2) resonates with the dual solenoid receiving coil (4), and finally converts the high-frequency AC power into stable DC power through the rectifier module (5) and outputs it to the battery.

[0047] The DC inverter module includes a DC voltage source and a full-bridge inverter circuit. The full-bridge inverter circuit is composed of four switching devices (MOSFETs) and operates according to a specific switching sequence to convert DC power into high-frequency AC power. At the same time, the high-frequency AC power generates a high-frequency alternating magnetic field, and energy is transferred through a coupling mechanism.

[0048] The compensation network is divided into the primary side S compensation network and the secondary side S compensation network, such as Figure 4 When working, the two primary compensation networks transfer energy to the secondary compensation network. The primary compensation network S includes primary compensation capacitors C1 and C2, primary coil inductance L 14 , L 13 and L 24 , L 23 The secondary side S compensation network includes a secondary side compensation capacitor C s , primary coil inductance L s .

[0049] The coupling mechanism is the core device of the power fluctuation suppression system of dynamic wireless power transmission, including the transmitting coil on the primary side and the receiving coil on the secondary side, such as Figure 2 , wherein the primary transmitting coil (3) adopts a composite solenoid coupling structure, and each transmitting coil comprises three sets of solenoid coils (L n1 ,L n2 ,L n3 ), where L n1 ,L n2 Wrapped around both sides of the nth coil, L n3 Wound on the n+1th coil, the coil current direction is the same. The inductance L on the nth coil n1 ,L n2 It will produce cross coupling with the inductance on the n+1th coil. The coupling inductance is M1, which is negative. L n3 This inductance, combined with the inductance of the n+1th coil, creates a positive cross-coupling, M2. Adjusting the number of turns in the transmitting coil allows M1 + M2 to equal 0. In this arrangement, the mutual inductances of adjacent transmitting coils theoretically cancel each other, achieving natural decoupling.

[0050] The secondary receiving coil is a double solenoid receiving coil (4), and its magnetic field is symmetrically distributed along its axial direction. When the receiving coil moves in the longitudinal direction (the laying direction of the transmitting coil), the distribution of the magnetic lines of force changes relatively slowly. This symmetry makes the coupling coefficient decrease slower than that of the planar coil.

[0051] The rectifier module is a single-phase bridge rectifier circuit, which includes four rectifier diodes and a filter capacitor, and plays the role of rectification and filtering. It can convert the received high-frequency alternating current into a stable direct current to supply the battery.

[0052] The following describes in detail a dynamic wireless power transmission power fluctuation suppression system for wireless charging devices such as electric vehicles and automated guided vehicles in conjunction with examples and drawings.

[0053] like Figure 1 As shown in the figure, the overall circuit structure of the power fluctuation suppression system for dynamic wireless power transmission of the present invention includes: (1) a DC inverter module; (2) a compensation topology; (3) a composite solenoid transmitting coil; (4) a dual solenoid receiving coil; and (5) a rectifier module.

[0054] like Figure 2 As shown, the transmitting coil adopts a composite solenoid transmitting coil. Each coil group contains three solenoid coils connected in series. The two coils L in the first group are connected in series. 11 and L 12 Wound on the first part of ferrite, L 13Wrapped around the second part of the ferrite, they are connected in series. 21 and L 22 Wound on the second part of the ferrite, L 23 Wrapped around the third ferrite, they are connected in series. The receiving coil uses a dual solenoid wound around the ferrite, connected in series. Because the solenoid coil itself has excellent longitudinal (transmitting coil arrangement direction) anti-skew effect, and the dual solenoid coil also has good lateral anti-skew effect, the mutual inductance between the decoupled transmitting coil and receiving coil is smooth and stable.

[0055] like Figure 3 As shown, there are 9 groups of cross couplings between adjacent transmitting coils of the composite solenoid transmitting coil, namely L 11 Same as L 21 , L 22 , L 23 , there is a set of cross coupling, L 12 Same as L 21 , L 22 , L 23 , there is a set of cross coupling, L 13 Same as L 21 , L 22 , L 23 , there is a group of cross coupling, a total of 9 groups. 14 For L 11 and L 12 Equivalent inductance, L 24 For L 21 and L 22 Equivalent inductance, due to L 23 Corresponding coil distance L 11， L 12 and L 13 Far away, cross coupling can be ignored. 14 Same as L 24 For parallel connection in the same direction, mutual inductance M1<0, L 14 Same as L 24 The two coils are connected in reverse parallel and the mutual inductance M2 is greater than 0. The decoupling effect between the transmitting coils can be achieved by adjusting the number of turns of the transmitting coil.

[0056] like Figure 4 As shown in the simplified equivalent circuit diagram of the decoupling, U1 is the input voltage of the first group of transmitting coils, U2 is the input voltage of the second group of transmitting coils, and U o is the output voltage; I1 and I2 are the resonant currents of the two sets of transmitting coils on the primary side, I s is the secondary side resonant current; C1 and C2 are the compensation capacitors of the two sets of transmitting coils on the primary side, C s is the secondary side compensation capacitor; L14 and L 13 is the self-inductance of the first set of primary coils, L 24 ,L 23 is the self-inductance of the second set of primary coils, L s is the self-inductance of the receiving coil; M1 is L 14 and L 24 The coupling mutual inductance between them, M2 is L 14 and L 24 The coupling mutual inductance between ps1 is the coupling mutual inductance between the first group of transmitting coils and receiving coils, M s2 is the coupling mutual inductance between the second set of transmitting coils and receiving coils; R L is the equivalent load. Analyzing the circuit shown in the figure, using Kirchhoff's voltage law mesh loop method, we get three expressions, namely:

[0057]

[0058] The circuit resonance condition is:

[0059]

[0060] Where w is the coupling resonant frequency. When the entire system is in a resonant state, the circuit appears purely resistive to the outside.

[0061] because Figure 4 The resistance of the primary and secondary coils and the parasitic resistance of the inductors and capacitors are ignored, so the model is a lossless model. The output power of the resonant compensation network DWPT under the lossless model can be expressed as:

[0062]

[0063] The conclusion can be drawn from the formula: output power P out With w 2 Inversely proportional to (M1+M2) 2 Inversely proportional to R L Inversely, (U1M s2 +U2M s1 ) 2 , when the system parameters are determined, P out Mutual inductance value M only with magnetic coupling mechanism s1 , M s2 It is related to the cross coupling M1 and M2 between the primary coils. The use of composite solenoids can eliminate the cross coupling between the transmitting coils, and M1 and M2 do not need to be considered. The power output size itself mainly depends on the mutual inductance value M of the magnetic coupling mechanism. s1 , M s2Therefore, under this condition, when the mutual inductance is stable, the output power reaches a stable state, that is, when the mutual inductance is stable during the movement of the power receiving body, the purpose of suppressing power fluctuations is achieved.

[0064] like Figure 5 As shown in the mutual inductance waveform diagram of the receiving body during the movement process of the present invention, the primary transmitting coil adopts a composite solenoid transmitting coil laid alternately, and the receiving coil is a double solenoid receiving coil. The mutual inductance waveform of the receiving coil achieves a smooth and stable effect during the movement process.

[0065] Those skilled in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0066] In the several embodiments provided in this application, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the division of the units described above is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. The above-mentioned units may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiment of the present invention.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A power fluctuation suppression system for dynamic wireless power transmission, characterized in that: include: DC inverter module, used to convert DC power into high-frequency AC power and control the start and stop of the transmitting coil; The compensation topology includes a primary-side S compensation network and a secondary-side S compensation network, connected to the transmitter and receiver respectively; The composite solenoid transmitting coil is composed of multiple alternately laid transmitting units. Each transmitting unit contains three sets of solenoid coils connected in series, and the current direction of each coil is the same. The double solenoid receiving coil is composed of two sets of series-connected solenoid coils symmetrically wound on ferrite; Rectifier module, used to convert the received high-frequency AC power into DC power output; in, The composite solenoid transmitting coil achieves natural decoupling by adjusting the number of coil turns so that the mutual inductance between adjacent transmitting units satisfies M1+M2=0; The axially symmetric magnetic field distribution of the dual solenoid receiving coil suppresses fluctuations in the coupling coefficient when the power receiver moves.

2. The power fluctuation suppression system for dynamic wireless power transmission according to claim 1, characterized in that: Each transmitting unit of the composite solenoid transmitting coil contains three sets of solenoid coils L connected in series. n1 , L n2 , L n3 ,in: L n1 , L n2 Wound on the nth ferrite, L n3 Wrapped around the n+1th section of ferrite, the current directions of each coil are the same.

3. The power fluctuation suppression system for dynamic wireless power transmission according to claim 2, characterized in that: In the composite solenoid transmitting coil, L n1 , L n2 The reverse coupling mutual inductance M1<0, L n3 The generated forward coupling mutual inductance M2>0, and M1 and M2 are offset by adjusting the number of turns.

4. The power fluctuation suppression system for dynamic wireless power transmission according to claim 1, characterized in that: The primary side S compensation network includes a first compensation capacitor C1 and a second compensation capacitor C2 connected in parallel, corresponding to two sets of transmitting coils respectively; the secondary side S compensation network includes a secondary side compensation capacitor C s ; Compensation parameters meet the resonance conditions: Where: ω is the system resonant angular frequency, L 13 , L 14 is the equivalent inductance of the first set of transmitting coils, L 23 , L 24 is the equivalent inductance of the second group of transmitting coils, and Ls is the inductance of the receiving coil.

5. The power fluctuation suppression system for dynamic wireless power transmission according to claim 1, characterized in that: The DC inverter module includes a DC voltage source and a full-bridge inverter circuit composed of four MOSFETs, and the rectifier module is a single-phase bridge rectifier circuit including four rectifier diodes and a filter capacitor.

6. The power fluctuation suppression system for dynamic wireless power transmission according to claim 1, characterized in that: The longitudinally symmetrical structure of the dual-solenoid receiving coil enables the mutual inductance change rate to be lower than that of a planar coil structure when the receiving coil moves in the laying direction of the transmitting coil.

7. The power fluctuation suppression system for dynamic wireless power transmission according to claim 1, characterized in that: The two groups of solenoid coils of the dual-solenoid receiving coil are wound around the same ferrite in an axially symmetrical manner, and the winding axis lines of the two groups of coils are parallel to the laying direction of the transmitting coil.

8. The power fluctuation suppression system for dynamic wireless power transmission according to claim 1, characterized in that: In the primary side S compensation network: The first compensation capacitor C1 is connected in parallel to the equivalent inductance L of the first group of transmitting coils 14 , L 13 ; The second compensation capacitor C2 is connected in parallel to the equivalent inductance L of the second group of transmitting coils 24 , L 23 .

9. The power fluctuation suppression system for dynamic wireless power transmission according to claim 1, characterized in that: The system uses position detection sensors to determine the position of the mobile power receiver in real time and controls the DC inverter module to start and stop the corresponding transmitting unit.

10. The power fluctuation suppression system for dynamic wireless power transmission according to claim 1, characterized in that: When the receiving coil moves in the arrangement direction of the transmitting coil, the mutual inductance value of the composite solenoid transmitting coil and the double solenoid receiving coil presents a smooth and stable waveform.

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