Constant-current constant-voltage self-switching dynamic wireless power transmission system based on hybrid topology

Abstract

The application relates to the technical field of electric energy transmission, and particularly discloses a constant-current constant-voltage self-switching dynamic wireless electric energy transmission system based on a hybrid topology. # The hybrid topology shares a switch tube with Class-E, utilizes E # The constant-current branch and the constant-voltage characteristic of the Class-E branch realize automatic switching of the charging mode according to load changes, without the need of an additional detection circuit and complex control; meanwhile, the double transmitting coils with orthogonal winding are cooperatively designed with the T-shaped ferrite structure, cross coupling is inhibited, the magnetic field is uniformly distributed, and the coupling coefficient retention rate is improved when the load is offset in each direction; the switch tube realizes ZVS in the full load range, loss is reduced, and the overall efficiency is above 90% at the turning load. The application simplifies the system structure, reduces the hardware cost, improves the stability and adaptability of dynamic charging, and has a good application prospect.

Description

Technical Field

[0001] This invention relates to the field of power transmission technology, and in particular to a constant current and constant voltage self-switching dynamic wireless power transmission system based on hybrid topology. Background Technology

[0002] With the increasing prevalence of new energy vehicles, IoT terminals, and industrial mobile robots, traditional wired charging methods face numerous limitations: cumbersome wiring leading to space occupation, wear and tear and safety hazards from repeated plugging and unplugging, and interrupted battery life of mobile devices. These issues make it difficult to meet the public's demand for convenient, unmanned, and continuous power supply. Dynamic Wireless Power Transfer (DWPT) technology, as an important branch of Wireless Power Transfer (WPT) technology, breaks through the limitations of static charging scenarios, enabling real-time, contactless energy transfer during load movement, providing a new approach to solving the battery life problem of mobile devices. Currently, the global wave of energy structure transformation and intelligent industrial upgrading provides broad application prospects for DWPT technology. DWPT technology can achieve uninterrupted power supply during the operation of new energy vehicles, automated guided vehicles (AGVs), and implantable medical devices, extending the continuous working time of the equipment, significantly reducing battery capacity requirements, and improving the overall system operating efficiency.

[0003] While DWPT technology demonstrates significant advantages in addressing mobile device battery life issues, practical applications often involve spatial movement between the receiver and transmitter, such as horizontal offset, angular deflection, or variations in spacing. These pose serious challenges to the system's efficiency and stability. Existing research addresses the power instability caused by coupling coefficient fluctuations in DWPT systems under different operating conditions primarily through three aspects: control system optimization, core topology, and magnetic field coupling mechanisms.

[0004] In terms of control systems, existing solutions achieve constant current output by combining Kalman filtering with model predictive control, or frequency tracking using a composite strategy of zero-voltage switching angle tracking and dynamic capacitor compensation matrix. However, these methods generally suffer from high computational complexity, cumbersome control logic, and the need for additional detection circuits and compensation capacitor matrices, leading to increased system costs and stringent hardware requirements for the controller. Regarding core topologies, researchers have proposed a composite topology combining LCC-LCC constant current and LCC-S constant voltage, achieving mode switching via a secondary AC switch, or constructing a simplified structure using a single-tube inverter P#LCC-S resonant network, or employing an electric field-coupled LCLC-S type compensation circuit. However, these topologies suffer from drawbacks such as difficult parameter design, unsuitability for high-power scenarios, poor adaptability to load changes, and short transmission distances that fail to meet the demands of medium-range dynamic wireless charging. Regarding magnetic field coupling mechanisms, existing research has constructed uniform magnetic fields to enhance anti-offset capabilities through improved flat solenoid coils, coupling mechanisms for DQDD transmission and OLDD reception, dual-path LCC-S compensation with DDQ and DD coils, and two-dimensional layouts of non-overlapping multi-transmitter coils. However, the above schemes are complex in structure, have stringent requirements for coil arrangement and magnetic core design, and have high overall implementation costs. Summary of the Invention

[0005] This invention provides a constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology. The technical problem it solves is that existing dynamic wireless power transfer systems have significant limitations in terms of control system complexity, topology load adaptability, and magnetic coupling mechanism anti-offset performance. It is difficult to achieve both constant current and constant voltage adaptive charging and stable and efficient dynamic power transfer without adding additional detection circuits and complex control strategies.

[0006] To address the above technical problems, this invention provides a constant current / constant voltage self-switching dynamic wireless power transfer system based on a hybrid topology, including a transmitter. The transmitter includes a first inductor L1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a switching transistor Q1, and a first transmitting coil L. p1 Second transmitting coil L p1 The first inductor L1, the second capacitor C2, and the switching transistor Q1 are connected in series between the positive and negative terminals of the input DC voltage source DC. The first transmitting coil L... p1 The first capacitor C1 is connected in series between the common terminal of the first inductor L1 and the second capacitor C2 and the negative terminal of the input DC voltage source DC. The third capacitor C3 and the second transmitting coil L... p2 The first inductor L1, the second capacitor C2, and the first transmitting coil L are connected in series between the common terminal of the second capacitor C2 and the switching transistor Q1 and the negative terminal of the input DC voltage source DC. p1 The switching transistor Q1 and the first capacitor C1 constitute E. #The circuit consists of a first inductor L1, a switching transistor Q1, a second capacitor C2, a third capacitor C3, and a second transmitting coil L. p2 To form a Class-E circuit.

[0007] Preferably, the system includes a receiving end, the receiving end including a first receiving coil L s1 Second receiving coil L s2 , with the first receiving coil L s1 Series compensation capacitor C s1 , and the second receiving coil L s2 Parallel compensation capacitor C s2 Connect the first receiving coil L s1 and series compensation capacitor C s1 The first rectifier circuit is connected to the second receiving coil L. s2 and parallel compensation capacitor C s2 The second rectifier circuit has a filter capacitor C connected in parallel with both the first and second rectifier circuits. O and parallel-connected filter capacitor C O The storage battery.

[0008] Preferably, E # The second capacitor C2 in the circuit is equivalent to C a and C b Two capacitors are connected in parallel, where capacitor C b and inductor L p1 To form a parallel resonance, capacitor C3 and inductor L in a Class-E circuit p2 A series resonance is formed, and the system's resonant angular frequency is... The inductor and capacitor parameters satisfy:

[0009] ,

[0010] in, For the second transmitting coil L p2 and the second receiving coil L s2 Mutual induction when facing each other.

[0011] Preferably, the system includes a transmitting mechanism, which includes a transmitting ferrite and a first transmitting coil L wound around the transmitting ferrite. p1 and the second transmitting coil L p2 The transmitting ferrite includes a rectangular body, an oblique plate disposed at one end of the rectangular body in the horizontal direction forming an acute angle with the rectangular body, and two vertical plates disposed at both ends of the rectangular body in the vertical direction forming a right angle with the rectangular body; the first transmitting coil L p1 The second transmitting coil L p2One horizontal winding and one vertical winding are applied to the rectangular body, with the horizontal and vertical directions arranged at equal intervals but not uniformly.

[0012] Preferably, the longitudinally wound transmitting coil is denser at the outer end and sparser at the inner end, with the coil spacing being an arithmetic sequence with a tolerance of d1, and is wound only on half of the rectangular body, adjacent to the oblique plate.

[0013] Preferably, the transversely wound transmitting coils are symmetrically dense on both sides and sparse in the middle, with the coil spacing being an arithmetic sequence with a tolerance of d2.

[0014] Preferably, the system includes a receiving mechanism, the transmitting mechanism including a receiving ferrite and a first receiving coil L wound on the receiving ferrite. s1 Second receiving coil L s2 The first receiving coil L s1 The second receiving coil L s2 One horizontal winding and one vertical winding together form an orthogonal, uniform grid on the square receiving ferrite.

[0015] Preferably, the longitudinally wound transmitting coil serves as the first transmitting coil L. p1 The transversely wound transmitting coil serves as the second transmitting coil L. p2 The longitudinally wound receiving coil serves as the first transmitting coil L p1 The first receiving coil L coupled s1 The transversely wound receiving coil serves as the second transmitting coil L p2 The coupled second receiving coil L s2 .

[0016] Preferably, the parameters of the transmitting mechanism and the receiving mechanism are designed using the following steps:

[0017] The dimensions of the receiver ferrite, the rectangular body, and the charging air gap are determined according to application requirements.

[0018] With the goal of maximizing the ratio of the coupling coefficient after the magnetic coupling mechanism is offset laterally to that when it is aligned, the height H of the vertical piece, the number of turns N1 of the longitudinally wound transmitting coil and its coil spacing tolerance d1 are determined on the basis that the total length L of the longitudinally wound transmitting coil is less than half the length of the receiving end ferrite.

[0019] The number of turns N2 of the transversely wound transmitting coil and its coil spacing tolerance d2 are determined with the goal of maximizing the ratio of the coupling coefficient after longitudinal offset of the magnetic coupling mechanism to that when it is aligned.

[0020] Preferably, the threshold for switching between system operating modes is the critical load resistance. The corresponding load point, The operating angular frequency of the system. For the first transmitting coil L p1 and the first receiving coil L s1 Mutual inductance when facing each other; when the battery load equivalent resistance R Bat <R T At this time, E # The circuit and the Class-E circuit provide complementary power output, and the system operates in constant current output mode; when R Bat >R T At this time, E # When the circuit is blocked, its output is open, the Class-E circuit works normally, and the system operates in constant voltage output mode.

[0021] The present invention provides a constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology. In terms of circuit topology, the system adopts an E... # And a hybrid topology of Class-E, where E # Sharing a single switching transistor with Class-E, it can effectively achieve zero-voltage switching (ZVS), reducing switching losses and improving the system's operating economy. Regarding the coupling mechanism, the receiving coil uses a tightly wound mesh, while the transmitting end is approximately "T-shaped." The coil is wound in both horizontal and vertical directions, arranged non-uniformly according to an arithmetic sequence. Furthermore, the left half of the transmitting end is designed with a U-shaped magnetic core, thereby constraining the magnetic field lines.

[0022] Overall, this system achieves constant current and constant voltage adaptive wireless charging based on a single switching transistor, without the need for additional mode detection circuits or complex control algorithms, relying solely on E # The inherent constant current and constant voltage output characteristics of the Class-E branch allow for automatic switching from constant current to constant voltage mode based on changes in the battery's equivalent load. Simultaneously, the synergistic design of orthogonally wound dual-emitting coils and a T-shaped ferrite structure effectively suppresses cross-coupling between coils and ensures a more uniform magnetic field distribution, significantly improving the coupling coefficient retention rate during lateral, longitudinal, and vertical offsets. Furthermore, the system maintains zero-voltage turn-on of the switching transistors across the entire load range, reducing switching losses, and achieving an overall efficiency exceeding 90% at transition loads. Therefore, this invention simplifies the system structure and reduces hardware costs while simultaneously ensuring stability, adaptability, and economy during dynamic charging, effectively addressing the main bottlenecks faced by existing DWPT systems in engineering applications. Attached Figure Description

[0023] Figure 1This is a circuit topology diagram of a constant current and constant voltage self-switching dynamic wireless power transfer system based on a hybrid topology provided in an embodiment of the present invention;

[0024] Figure 2 This is an equivalent model diagram of the DWPT system based on the fundamental wave approximation method provided in the embodiments of the present invention;

[0025] Figure 3 This is an equivalent model diagram of the DWPT system after the transmitter power supply equivalent transformation provided in the embodiments of the present invention;

[0026] Figure 4 This is an equivalent model diagram of the system in constant current output mode and constant voltage output mode;

[0027] Figure 5 This is a schematic diagram of the coupling mechanism provided in an embodiment of the present invention, including a perspective view, a top view of the transmitting mechanism, and a top view of the receiving mechanism;

[0028] Figure 6 This is a graph showing the effect of the vertical plate height H on the coupling coefficient.

[0029] Figure 7 It is a graph showing the variation of longitudinal coil mutual inductance and coupling coefficient with X-axis offset distance under different coil spacing tolerances;

[0030] Figure 8 This is a comparison diagram of the magnetic flux density distribution between a traditional flat solenoid and the dual-winding T-type solenoid coil of this invention;

[0031] Figure 9 This is a diagram showing the effects of the longitudinal and transverse coils on the magnetic field distribution;

[0032] Figure 10 This is a magnetic flux density distribution diagram of the XY plane of the transmitting mechanism under different combinations of coil spacing tolerances and number of turns;

[0033] Figure 11 These are the ZVS waveforms of the switching transistor under different load resistances;

[0034] Figure 12 These are waveforms of the input voltage and current before rectification under different load resistances;

[0035] Figure 13 It is a graph showing the changes in system output voltage and output current as a function of load resistance;

[0036] Figure 14 This is a waveform diagram of the ZVS operation of the switching transistor under different load resistors in constant current output mode;

[0037] Figure 15 This is a waveform diagram of the ZVS operation of the switching transistor under different load resistors in constant voltage output mode;

[0038] Figure 16 E at different offset positions in constant current output mode # Voltage and current waveforms before branch rectification;

[0039] Figure 17 These are the voltage and current waveforms of the Class-E branch before rectification at different offset positions in constant current output mode;

[0040] Figure 18 E is at different offset positions in constant voltage output mode # Voltage and current waveforms before branch rectification;

[0041] Figure 19 These are waveforms of the Class-E branch voltage and current before rectification at different offset positions in constant voltage output mode.

[0042] Figure 20 This is a dynamic waveform diagram of load switching in constant current output mode;

[0043] Figure 21 This is a dynamic waveform diagram of load switching in constant voltage output mode;

[0044] Figure 22 It is a graph showing the changes in system output power and overall efficiency with load when the coupling mechanism is properly aligned;

[0045] Figure 23 This is a distribution diagram of the loss percentage of each part of the experimental system. Detailed Implementation

[0046] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The embodiments are given for illustrative purposes only and should not be construed as limiting the present invention. The accompanying drawings are for reference and illustration only and do not constitute a limitation on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from the spirit and scope of the present invention.

[0047] The constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology provided in this invention has the following circuit topology: Figure 1 As shown, it includes a transmitter and a receiver. The transmitter includes a connected input DC voltage source DC and a hybrid topology, which includes a first inductor L1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a switching transistor Q1, and a first transmitting coil L. p1 Second transmitting coil L p1 The first inductor L1, the second capacitor C2, and the switching transistor Q1 are connected in series between the positive and negative terminals of the input DC voltage source DC. The first transmitting coil L... p1The first capacitor C1 is connected in series between the common terminal of the first inductor L1 and the second capacitor C2 and the negative terminal of the input DC voltage source DC. The third capacitor C3 and the second transmitting coil L... p2 The capacitors L1, C2, and L3 are connected in series between the common terminal of the second capacitor C2 and the switching transistor Q1, and the negative terminal of the input DC voltage source DC. Q1 is a single-transistor inverter switch. p1 Q1 and C1 constitute E # Circuit, L1, Q1, C2, C3, L p2 Constructing a Class-E circuit, E # The circuit shares the same switching transistor Q1, inductor L1, and capacitor C2 with the Class-E circuit, utilizing E # The constant current characteristic of the circuit and the constant voltage characteristic of the Class-E circuit can achieve adaptive switching between constant current and constant voltage during the charging process.

[0048] The receiving end includes a first receiving coil L s1 Second receiving coil L s2 , with the first receiving coil L s1 Series compensation capacitor C s1 , and the second receiving coil L s2 Parallel compensation capacitor C s2 Connect the first receiving coil L s1 and series compensation capacitor C s1 The first rectifier circuit (a full-bridge rectifier composed of diodes D1, D2, D3, and D4) is connected to the second receiving coil L. s2 and parallel compensation capacitor C s2 The second rectifier circuit (a full-bridge rectifier composed of diodes D5, D6, D7, and D8) is connected in parallel with the filter capacitor C of the first and second rectifier circuits. O and parallel-connected filter capacitor C O The storage battery. Figure 1 In the middle, L p1 L p2 L is the self-inductance of the first and second transmitting coils. s1 L s2 M is the self-inductance of the first and second receiving coils. p1s1 M p2s2 It is the mutual inductance between the two sets of transceiver coils (due to structural design, there is no cross mutual inductance; the structural design will be explained in detail below), and R is the internal resistance of the battery. V in and I in V represents the system input voltage and current. p1 V p2 V is the AC voltage of the first and second transmitting coils. R1 V R2 I represents the input voltage across the first and second rectifier circuits.p1 I p2 I represents the alternating current of the first and second transmitting coils, respectively. s1 I s2 The AC currents of the first and second receiving coils are respectively, V Bat and I Bat This refers to the system output voltage and current.

[0049] For ease of analysis, the transmitter E # The circuit uses current source I Inv As an equivalent input, the Class-E circuit uses a voltage source U. Inv As an equivalent input, the load of the series compensation branch is equivalent to an AC resistance R. AC1 The load of the parallel compensation branch is equivalent to an AC resistance R. AC2 E # The capacitor C2 in the circuit is equivalent to C a and C b Two capacitors connected in parallel satisfy: The capacitor C b and inductor L p1 To form a parallel resonance, capacitor C3 and inductor L in a Class-E circuit p2 A series resonance is formed. The DWPT system topology is analyzed using the fundamental frequency approximation method, yielding the equivalent model of the DWPT system as follows: Figure 2 As shown, the entire system is divided into three parts: the transmitter equivalent circuit, the receiver series compensation branch, and the receiver parallel compensation branch.

[0050] System resonant angular frequency The inductor and capacitor parameters satisfy:

[0051] (1)

[0052] Based on the characteristics of this Class E inverter, the input inductance L in The resonant capacitor C1 resonates at q times the resonant frequency; when the duty cycle D = 0.5, the resonant frequency ratio is q = 1.29, and the capacitor C... a It is 2.11 times that of C1, and the relevant parameter calculation method satisfies: , .

[0053] To facilitate a clearer study of the DWPT system circuit topology model, E is now discussed. #The equivalent input current source on the circuit side is transformed into a voltage source through power supply equivalence transformation, thus forming a parallel structure of SS and SP topologies. The SS topology exhibits a constant current characteristic with a constant output current, while the SP topology exhibits a constant voltage characteristic with an output voltage insensitive to load changes. The equivalent model of the DWPT system after power supply equivalence transformation is as follows: Figure 3 As shown.

[0054] Figure 3 The diagram shows the equivalent model of the DWPT system after the transmitter power supply has been transformed. This is when the system operates at the resonant angular frequency. (i.e., the operating angular frequency of switching transistor Q1) Equal to the system's resonant angular frequency When ), for Figure 3 Using Kirchhoff's voltage law, we can obtain equation (2):

[0055] (2)

[0056] The expressions for the currents in each branch are obtained as shown in equation (3):

[0057] (3)

[0058] in, Equivalent impedance for parallel compensation at the receiving end:

[0059] (4)

[0060] E can be obtained from equation (3) # The input impedances of the circuit and the Class-E circuit respectively and The two are connected in parallel to form the total input impedance of the system. :

[0061] (5)

[0062] Output voltage and for:

[0063] (6)

[0064] At this time, let the output voltage and If the amplitudes are equal, the equivalent load resistance value can be obtained. For ease of subsequent analysis of the system's operating mode switching characteristics, this value is defined as the critical load resistance R. T :

[0065] (7)

[0066] It can be seen from equations (3) and (6) that the current and voltage The expression is independent of the load, further proving that E # The constant current output characteristics of the circuit and the constant voltage output characteristics of the Class-E circuit.

[0067] Since the two compensation branches at the receiving end are rectified by the rectifier bridge and filtered by the filter capacitor, and then connected in parallel, the equivalent resistance of the battery load is:

[0068] (8)

[0069] The threshold for switching between system operating modes is the critical load resistance R. T The corresponding load point. When R Bat <R T At that time, V R1 >V R2 At this time, E # The circuit and the Class-E circuit provide complementary power output, and the system operates in constant current output mode (CCO mode); when R Bat >R T At that time, V R1 <V R2 At this time, E # The circuit is blocked, its output is open, the Class-E circuit works normally, and the system operates in constant voltage output mode (CVO mode). Compared to a standalone E... # The circuit and Class-E circuit, this single-transistor hybrid compensation topology can operate over a wider range of loads and has better adaptability to load variations.

[0070] The switching between CCO and CVO modes is determined by the battery's internal resistance. When the battery's internal resistance is below the critical load resistance, the system switches to constant current output; when the battery's internal resistance reaches the critical load resistance, the system switches to constant voltage output. This mechanism ensures that the system can automatically adjust its operating mode according to the load, avoiding cumbersome control methods and thus optimizing the charging process efficiency. The system's charging mode switching response rate is related to the rate of change of the battery's internal resistance, rather than a fixed time threshold.

[0071] Figure 4 This is an equivalent model for the two operating modes of the system. Figure 4 (a) represents the CCO working mode. Figure 4 (b) shows the CVO operating mode. At the start of charging, the battery's equivalent internal resistance is low, and V... R2 The voltage amplitude is relatively small, and the output amplitude is mainly determined by V. R1 Decision, at this time V R1 >V R2 The system operates in CCO mode, E# The circuit and the Class-E circuit provide complementary power output. The output DC voltage V Bat The expression is:

[0072] (9)

[0073] Among them, V R1 This represents the effective voltage value of the full-bridge rectifier in the series compensation branch.

[0074] Based on the conservation of input and output power, the battery charging current can be further expressed as:

[0075] (10)

[0076] Therefore, it can be seen that during the initial charging phase, the system can achieve CCO characteristics independent of the load.

[0077] When the battery is charged at a constant current until its internal resistance is greater than the critical load resistance, R AC1 When the resistance approaches infinity, the branch is in an open circuit state, and the branch current I is compensated in series. R1 The impedance reflected to the primary side is approximately zero. At this point, the parallel compensation branch operates normally, while the series compensation branch is essentially inactive. The system output mainly depends on V. R2 The hybrid compensation topology degenerates into the SP compensation topology, corresponding to the output DC voltage V. Bat The expression is:

[0078] (11)

[0079] Therefore, the system can also achieve CVO characteristics independent of load.

[0080] Furthermore, the system can handle both short-circuit and open-circuit faults: it automatically enters CCO mode when a short circuit occurs and switches to CVO mode when an open circuit occurs, achieving stable operation under both conditions. This capability eliminates the need for additional detection and protection circuits, thus improving the system's simplicity and reliability.

[0081] Traditional flat solenoids possess the inherent property of a dual flux loop, exhibiting good resistance to longitudinal offset. However, their magnetic field is mainly concentrated in the directly facing region and disperses outwards. During lateral offset, the effective coupling area decreases sharply, and the mutual magnetic reluctance increases drastically, resulting in poor resistance to lateral offset. When lateral offset occurs at the receiving end, the coupling coefficient drops sharply. To improve the offset resistance of the DWPT system, especially the lateral offset, this embodiment designs a coupling mechanism with a special structure, as shown below. Figure 5 As shown, Figure 5In Figure 5(a), the coupling mechanism is shown in perspective. Figure 5(b) is a top view of the transmitting mechanism (the transmitting ferrite and the first and second transmitting coils wound around the transmitting ferrite). Figure 5(c) is a top view of the receiving mechanism (the receiving ferrite and the first and second receiving coils wound around the receiving ferrite). Figure 5 As shown, the first and second receiving coils are wound horizontally and vertically, respectively, forming an orthogonal, uniform grid on the square receiving ferrite core. The transmitting ferrite core includes a rectangular body, a beveled plate at one end of the rectangular body forming an acute angle (preferably 30°) with the body, and two vertical plates at both ends of the rectangular body forming a 90° angle with the body. The two vertical plates and the rectangular body together form a U-shaped structure, making the magnetic field distribution more uniform. The first and second transmitting coils are wound horizontally and vertically on the rectangular body, respectively, with equal intervals in both directions. The vertically wound transmitting coil is wound from dense to sparse from the outer end to the inner end, with the coil spacing following an arithmetic progression with a tolerance of d1, and is only wound on half of the rectangular body (the right side in this example), adjacent to the beveled plate. Combined with the beveled plate, this makes the magnetic field distribution more uniform, improving the system's resistance to lateral offset to a certain extent and compensating for the legacy problems of traditional flat solenoids. The transversely wound transmitting coil exhibits a symmetrical arrangement, with denser coils at both ends and sparser coils in the middle. The coil spacing follows an arithmetic progression with a tolerance of d². Combined with the vertical plates on both sides, this helps to concentrate magnetic field lines, enhancing the system's resistance to lateral deviation and increasing the vertical height of the magnetic field. Both the transmitting and receiving coils in the DWPT system are made of Litz wire wound on a flat solenoid. In this embodiment, the longitudinally wound transmitting coil serves as the E... # The transmitting coil of the circuit, i.e., the first transmitting coil L p1 (Coupled with it is a longitudinally wound receiving coil, serving as the first receiving coil L) s1 The transversely wound transmitting coil serves as the transmitting coil for the Class-E circuit, i.e., the second transmitting coil L. p2 (Coupled with it is a laterally wound receiving coil, serving as the second receiving coil L) s2 The orthogonal relationship between coils with different windings allows for mutual decoupling, eliminating cross-inductance. Using this coupling mechanism, combined with specific circuit design, a charging method that first maintains constant current and then constant voltage can be implemented as the battery load gradually increases.

[0082] The coupling coefficient of the magnetic coupling mechanism in the DWPT system is directly related to the dimensions of the transmitting and receiving coils and ferrite. Therefore, parameter optimization of the proposed dual-winding T-type solenoid coil magnetic coupling mechanism is necessary. The installation position of the transmitting end is relatively fixed, and its dimensions are generally not easily changed after installation. Since the coil needs to be wound on the ferrite, the ferrite size directly affects the coil's planar dimensions. Taking the dimensions of the transmitting end ferrite vertical sheet as 270mm × 96mm × 2mm as an example, in practical applications, the parameters of the receiving end should be determined according to the dimensions of the specific charging equipment. However, for the sake of simplifying the analysis, the receiving end ferrite size is fixed at 100mm × 100mm × 2mm, and the air gap distance h is taken as 30mm.

[0083] The height H of the vertical plate, the number of turns N1 of the longitudinally wound transmitting coil, and the coil spacing tolerance d1 are parameters to be further optimized. To better reflect the anti-offset performance of the magnetic coupling mechanism, the coupling coefficient retention rate (CCRR) is first defined for quantitative comparison, and its expression is:

[0084] (12)

[0085] Where, k x k and k0 are the coupling coefficients of the magnetic coupling mechanism after offset and when it is aligned, respectively.

[0086] The influence of the height H of the vertical piece on the coupling coefficient k was obtained using Ansys Maxwell finite element simulation software. Since the vertical piece exhibits a symmetrical structure, only the case where the offset distance along the X-axis is [0mm~80mm] was verified. The simulation results are as follows. Figure 6 As shown. By Figure 6 It can be seen that the CCRR is basically the same when the height H is between 0mm and 8mm, and the heights overlap. However, when it exceeds 8mm, the CCRR decreases. In order to ensure that the magnetic coupling mechanism still has a certain anti-offset performance in the vertical height, the height H is now selected as 8mm.

[0087] Because the transmitting coil is wound non-uniformly according to an arithmetic sequence, the number of turns N is closely related to the tolerance d of the coil spacing. Meanwhile, the constant current phase during battery charging is the main charging period, primarily focusing on speed and efficiency. This places high demands on the E... # The longitudinal coil of the circuit's transmitting coil is set to a standard, so the following analysis will mainly focus on the longitudinal coil.

[0088] Let the longitudinally wound transmitting coil be a one-dimensional flattened coil with a total length of L, number of turns of N1, width of Litz wire of a, coil spacing tolerance of d1, and distance of b between the left end of the first turn of the coil and the leftmost side of the flat solenoid. Then the total length can be expressed as:

[0089] (13)

[0090] The longitudinally wound transmitting coil is only distributed in the right half of the mechanism, therefore L should be less than half the length in the receiving end magnetic core (set to 270mm in this embodiment).

[0091] (14)

[0092] Taking the width of the Litz wire as 3mm, the distance between the left end of the first turn and the leftmost side of the flat solenoid is 5mm. Combining equations (13) and (14), we can obtain:

[0093] (15)

[0094] Equation (15) shows the relationship between the number of coil turns N1 and the coil spacing tolerance d1. With appropriate parameter selection, several sets of data as shown in Table 1 can be obtained.

[0095] Table 1. Parameter values ​​for longitudinally wound transmitting coils

[0096]

[0097] To further determine the coil turns N1 and coil spacing tolerance d1, finite element simulation software was used to simulate and analyze the above three sets of parameters. Since the longitudinal coil is only distributed in the right half of the magnetic coupling mechanism, only the case where the lateral offset distance along the X-axis (the length direction of the transmitting end magnetic core) is [-85mm~0mm] was verified. The simulation results are as follows. Figure 7 As shown. Figure 7 (a) shows coil L under different coil spacing tolerances d1. p1 With L s1 Mutual induction between L p1s1 The graph showing the change in lateral offset distance along the X-axis indicates that when d1 = 0.1 mm, the mutual inductance L... p1s1 The mutual inductance is significantly greater than the values ​​for d1=0.5mm and d1=1mm, meaning more energy is transferred in the same amount of time. When the coil spacing decreases, more turns can be wound on the same volume of ferrite. Mutual inductance is directly proportional to the product of the number of turns in the two coils. Therefore, as the coil spacing tolerance d1 decreases, the number of turns N1 increases, and the mutual inductance M increases. Figure 7 The comparison results of the three cases shown in (a) also prove this point. Figure 7Figure (b) shows the variation of the coupling coefficient k with the lateral offset distance along the X-axis under different coil tolerances d. It can be seen that both the coupling coefficient k and the rate of change of the coupling coefficient (CCRR) are maximized when d1 = 0.1 mm. This demonstrates that its anti-offset performance is better than that when d1 = 0.5 mm and d1 = 1 mm. In summary, to meet the standards of "fast" and "efficient" during constant current charging, the coil spacing is chosen to be d1 = 0.1 mm. As shown in Table 1, this results in 29 coil turns.

[0098] The transversely wound transmitting coil employs the same arithmetic interval non-uniform winding method as the longitudinally wound transmitting coil. Since solenoid coils naturally possess good anti-misalignment performance in the longitudinal direction, the longitudinally wound transmitting coil already undertakes the main task of transverse anti-misalignment, while the transversely wound transmitting coil is primarily used to compensate for uneven magnetic field distribution during longitudinal misalignment. Referring to the longitudinal optimization process (aiming to maximize the ratio of the coupling coefficient after longitudinal misalignment to that when aligned), the final determined spacing tolerance d2 for the transversely wound transmitting coil is 2mm, and the number of turns N2 is 11 turns.

[0099] Based on the above optimization results, the overall dimensional parameters of the dual-winding T-type solenoid coil magnetic coupling mechanism are shown in Table 2.

[0100] Table 2. Parameter values ​​for the magnetic coupling mechanism of the dual-direction T-type solenoid coil.

[0101]

[0102] To further demonstrate the anti-offset characteristics of the proposed dual-winding T-type solenoid coil magnetic coupling mechanism, without considering the receiver, only the transmitting coil is excited and analyzed. Ansys Maxwell finite element simulation software is used to simulate and compare the dual-winding T-type solenoid coil with a traditional flat solenoid. The simulation results are as follows: Figure 8 As shown. Figure 8 In the middle (a), the magnetic flux density distribution of a conventional flat solenoid is shown. Figure 8 (b) shows the magnetic flux density distribution of a double-wound T-type solenoid coil. Through analysis of... Figure 8 (a) and Figure 8 The comparison in (b) shows that the magnetic flux density distribution of the proposed dual-winding T-type solenoid coil magnetic coupling mechanism is superior to that of the traditional flat solenoid. This is because the dual-winding T-type solenoid coil adds a ferrite baffle at a 30° angle to the horizontal plane on the right side of the horizontal direction, and adds a ferrite baffle at a 90° angle to the horizontal plane at each end of the vertical direction to form a U-shaped structure. This structure concentrates the magnetic lines of force, making the magnetic flux density distribution more uniform and enhancing the anti-deflection capability of the magnetic coupling mechanism to a certain extent.

[0103] To further analyze the influence of the longitudinally and transversely wound transmitting coils (referred to as longitudinal coils and transverse coils) on the magnetic field distribution, a simulation analysis was performed using finite element software. The simulation results are as follows: Figure 9 As shown, Figure 9 (a) and Figure 9 (b) shows the effects of the longitudinal and transverse coils on the magnetic field distribution, respectively. Figure 9 As can be seen in (a), the longitudinal coil significantly enhances the magnetic field strength on the left side of the solenoid, solving the problem of weak magnetic field at the X-axis edge of traditional solenoids and effectively improving the anti-offset capability of the magnetic coupling mechanism along the X-axis. Because no coil is wound on the left side of the solenoid, the magnetic field strength is somewhat weakened. From... Figure 9 As can be seen in (b), the winding of the transverse coil effectively enhances the magnetic field strength on the left side of the solenoid, solving the aforementioned problem. At the same time, the magnetic field density distribution of the entire solenoid is uniform, further demonstrating the feasibility of this coupling mechanism.

[0104] The magnetic coupling mechanism of the transmitter with the same receiver but different numbers of turns in the longitudinal coil was simulated and analyzed using Ansys Maxwell finite element simulation software. To ensure the validity of the simulation results, the core material, Litz wire specifications, air gap distance, and receiver coil parameter types were kept consistent across different simulation models. The longitudinal coil spacing tolerance and number of turns were used as variables to build multiple sets of magnetic coupling mechanism simulation models. Analysis was performed only on the transmitter mechanism without a receiver, and the magnetic flux density distribution in the XY plane of the transmitter mechanism was obtained as follows: Figure 10 As shown, Figure 10 In section (a), the corresponding value is d=0.1mm and N=29 turns. Figure 10 (b) corresponds to d=0.5mm and N=18 turns. Figure 10 In section (c), d=1mm and N=13 turns are corresponding to this. (Comparison) Figure 10 (a) Figure 10 (b) and Figure 10 In (c), it can be clearly seen that the magnetic flux distribution density of the transmitting mechanism with coil tolerance d=0.1mm and number of turns N=29 is significantly better than the other two cases. This indicates that, to a certain extent, reducing the coil spacing tolerance to increase the number of coil turns can make the magnetic flux density more uniform and the anti-offset performance more excellent.

[0105] To verify the soft-switching characteristics and self-switching characteristics of the proposed single-transistor hybrid compensation topology, a single-transistor WPT system circuit simulation model was built using MATLAB / Simulink software. The circuit parameters are shown in Table 3.

[0106] Table 3 Simulation Model Circuit Parameters

[0107]

[0108] Figure 11 For different R Bat Simulation results show the ZVS operating waveform of the switching transistor. Figure 11 (a) Figure 11 (b) corresponds to R respectively Bat =1Ω and R Bat =10Ω. For example... Figure 11 As shown in (a), when R Bat When the resistance is 1Ω, the circuit operates in CCO mode, and the peak drain-source voltage V of the switching transistor is... DS The drain-source voltage V is 121.0V before the switching transistor is turned on. DS The value has been reduced to 0, achieving ZVS turn-on of the switching transistor. For example... Figure 11 As shown in (b), when R Bat When the impedance is 10Ω, the circuit operates in CVO mode, and the peak drain-source voltage V of the switching transistor is... DS The drain-source voltage V before the switching transistor is turned on is 122.6V. DS The voltage has also dropped to 0, achieving ZVS turn-on of the switching transistor. This proves that the switching transistor can achieve zero-voltage turn-on regardless of the load in both CCO and CVO modes.

[0109] Figure 12 For different R Bat The simulation results show the input voltage and current waveforms before rectification. Figure 12 (a) Figure 11 (b) corresponds to R respectively Bat =1Ω and R Bat =10Ω. For example... Figure 12 As shown in (a), when R Bat When the Ω is 1Ω, the circuit operates in CCO mode, and the effective value of the input voltage before rectification in branch 1 and branch 2 is V. R1 and V R2 The voltages are 5.63V and 5.26V respectively, and the effective value of the current I is... R1 and I R2 The currents are 3.32A and 1.29A respectively, with the voltage and current in phase and both in a resonant state. For example... Figure 12 As shown in (b), when R Bat When the resistance is 10Ω, the circuit operates in CVO mode, E # The input voltage V before rectification in the branch R1 The effective value is 12.75V, and the current I is... R1 The effective value is 0.03A, E # The branch has almost no power output; the pre-rectified input voltage V of the Class-E branch R2 The effective value is 12.84V, and the current I... R2 The effective value is 1.60A, and the voltage and current are in phase. It can be seen that when... At that time, V R1 >V R2 At this time, E # The branch and the Class-E branch provide complementary power output; when At that time, V R1 <V R2 At this time, E # When a branch is blocked, its output is open, and the Class-E branch works normally, consistent with the theoretical analysis.

[0110] Figure 13 Output voltage and current variation curves based on the simulation results. When R Bat When the resistance is 1Ω, the output voltage V Bat and output current I Bat They are 2.05V and 2.05A respectively; when R Bat When the resistance is 3Ω, the output voltage V Bat and output current I Bat The voltages are 6.06V and 2.02A respectively, when R Bat When the resistance is 5Ω, the output voltage V Bat and output current I Bat The voltages are 9.90V and 1.98A respectively, with the output current remaining approximately 2A and fluctuating by less than 2.5%, demonstrating that the system circuit topology possesses load-independent CCO characteristics. When R... Bat When the resistance is 5Ω, the output voltage V Bat and output current I Bat The voltages are 9.90V and 1.98A respectively, when R Bat When the resistance is 10Ω, the output voltage V Bat and output current I Bat The voltages are 10.08V and 1.008A respectively, when R Bat When the resistance is 15Ω, the output voltage V Bat and output current I Bat The voltages are 10.15V and 0.677A respectively, with the output voltage remaining approximately 10V and fluctuating by less than 1.5%, demonstrating that the system circuit topology possesses load-independent CVO characteristics. Therefore, the load breakover resistance R... T Approximately 5Ω, when R Bat <R T When R is in CCO mode, the system operates in CCO mode; when R is in CCO mode, the system operates in CCO mode. Bat >R T At this time, the system operates in CVO mode. During the initial charging phase, the battery terminal voltage is low, the equivalent load resistance is small, and the system output is close to its high current demand state. At this time, E #Because of its constant current characteristic within the short-circuit to turning load resistance range, the branch becomes the main energy transfer channel, maintaining the output current around 2A to achieve constant current charging. As the battery voltage increases, the output equivalent load resistance gradually increases, E # The branch gradually deviates from its optimal constant current operating range, while the equivalent transfer capability of the Class-E branch increases. When the output voltage reaches around 10V, the system's dominant power transfer path shifts from E... # The branch naturally shifts to the Class-E branch, and the output voltage is limited to a constant voltage value. The charging current gradually decreases as the battery state of charge increases, thereby achieving an adaptive switching from constant current to constant voltage.

[0111] To verify the soft-switching, anti-offset performance, and adaptive switching between CCO and CVO of the proposed single-tube WPT system, an experimental prototype platform was built. The circuit parameters are shown in Table 4. An electronic load was used to simulate the battery internal resistance, and its setting range covered the theoretically derived operating state inflection point. The transmitting mechanism used a double-wound T-type solenoid coil with ferrite dimensions of 270*96*2mm, and the receiving mechanism used a grid-type solenoid coil with ferrite dimensions of 100*100*2mm. All windings were made of 0.1*300 strand Litz wire, and the transmission distance between the transmitting and receiving coils was 30mm. The remaining structural parameters were consistent with those listed in Table 2.

[0112] Table 4 Circuit parameters of the experimental prototype

[0113]

[0114] Figure 14 For the experimental prototype under different loads in CCO mode R Bat ZVS operating waveform of the lower switching transistor Figure 14 (a) Figure 14 (b) Figure 14 (c) Figure 14 (d) corresponds to R respectively Bat The available Ω values ​​are 1Ω, 2Ω, 3Ω, and 4Ω. Figure 14 The results show that when the load R Bat The peak drain-source voltage V of the switching transistor at 1Ω, 2Ω, 3Ω and 4Ω respectively. DS The voltages are 116.8V, 116.4V, 116.4V, and 116.2V respectively. Before the switching transistor is turned on, V... DS All values ​​were reduced to 0, achieving ZVS activation. The above results verify that the proposed system possesses good ZVS characteristics in CCO mode and is unaffected by load changes.

[0115] Figure 15 For the experimental prototype under different loads in CVO mode R Bat ZVS operating waveform of the lower switching transistor Figure 15(a) Figure 15 (b) Figure 15 (c) Figure 15 (d) corresponds to R respectively Bat are 5Ω, 10Ω, 15Ω and 20Ω. Figure 15 The results show that when the load R Bat The peak drain-source voltage V of the switching transistor at 5Ω, 10Ω, 15Ω and 20Ω respectively. DS The voltages are 116V, 115.9V, 115.96V, and 115.94V respectively, before the switching transistor is turned on. DS All values ​​were reduced to 0, achieving ZVS activation. The results show that the proposed system also possesses stable ZVS characteristics in CVO mode, unaffected by load changes.

[0116] When a low-power mobile device enters the coupling mechanism, due to the equivalent load resistance R Bat The current is relatively small, and the system charging mode is in CCO mode at this time. Figure 16 For different positions E in CCO mode of the test prototype # Voltage and current waveforms before branch rectification. Figure 17 The above are waveforms of the Class-E branch voltage and current before rectification at different locations in CCO mode of the test prototype. Figure 16 neutralization Figure 17 In the diagram, (a), (b), (c), and (d) correspond to positive alignment, offset 30mm along the X-axis, offset 30mm along the Y-axis, and offset 10mm along the Z-axis, respectively. Figure 16 The results in (a) show that when the coupling mechanism is in positive alignment, E # The effective values ​​of the voltage and current before rectification in the branch circuit are 7.24V and 3.96A, respectively. Figure 17 The results in (a) show that the effective values ​​of the voltage and current before rectification in the Class-E branch are 7.16V and 1.96A, respectively. Figure 16 neutralization Figure 17 Figures (b), (c), and (d) show that when offset along the X, Y, and Z axes by 30mm, 30mm, and 10mm respectively, the effective values ​​of the pre-rectification voltage and current in both branches increase. This is because the mutual inductance between the magnetic coupling mechanisms decreases slightly during the offset process, which is consistent with the theoretical derivation. At this time, E # The Class-E branch and the Class-E branch work simultaneously, with complementary power output. The voltage and current phases before rectification remain consistent, indicating that the system is continuously in a resonant state, thus ensuring the stable operation of the system.

[0117] As mobile devices continue to charge in CCO mode, their equivalent load resistance R... Bat Gradually increase, when R Bat >R TAt this time, the system charging mode enters CVO mode. Figure 18 For different positions of E in CVO mode of the test prototype # Voltage and current waveforms before branch rectification. Figure 19 The above are the voltage and current waveforms of the Class-E branch before rectification at different locations in CVO mode of the test prototype. Figure 18 neutralization Figure 19 In the diagram, (a), (b), (c), and (d) correspond to positive alignment, offset 30mm along the X-axis, offset 30mm along the Y-axis, and offset 10mm along the Z-axis, respectively. Figure 18 The results in (a) show that when the coupling mechanism is in positive alignment, E # The effective values ​​of the voltage and current before rectification in the branch circuit are 8.04V and 0.02A, respectively. Figure 19 The results in (a) show that when the coupling mechanism is in positive alignment, the effective values ​​of the voltage and current before rectification in the Class-E branch are 10.04V and 1.72A, respectively. Figure 18 neutralization Figure 19 Figures (b), (c), and (d) show that when offset along the X, Y, and Z axes by 30mm, 30mm, and 10mm respectively, the effective values ​​of the voltage and current before rectification in the Class-E branch are improved. # The current before rectification in the branch circuit is always close to 0. This is because, in CVO mode, E # The Class-E branch was blocked, and its output was approximately open, while the Class-E branch operated normally. The voltage and current phases remained consistent before rectification in the Class-E branch, indicating that the Class-E branch was always in a resonant state. This experimental result is consistent with theoretical analysis.

[0118] Figure 20 This is a dynamic waveform diagram of load switching in CCO mode of the experimental prototype. (Source: [Insert Source Here]) Figure 20 It can be seen that when the equivalent load resistance R Bat When dynamically switching from 1Ω to 2Ω to 3Ω, the output voltage V Bat The voltage changes from 2.06V to 4.11V to 6.07V, and the output current I... Bat The output current fluctuates by less than 3% as it changes from 2.06A to 2.05A to 2.02A. The voltage and current changes consistently satisfy Ohm's law.

[0119] Figure 21 This is a dynamic waveform diagram of load switching in CVO mode of the experimental prototype. Figure 21 It can be seen that when the equivalent load resistance R Bat When dynamically switching from 5Ω to 10Ω to 15Ω, the output current I Bat The output voltage V changes from 1.99A to 1.01A to 0.68A. BatThe output voltage fluctuates by less than 1.5% as it changes from 9.94V to 10.06V to 10.13V. The voltage and current changes consistently satisfy Ohm's law.

[0120] Figure 22 The output power efficiency curves of the positively aligned coupling mechanism are shown. Figure 22 It can be seen that both the system output power and overall efficiency show a trend of first increasing and then decreasing. The maximum output power of 19.78W and the maximum overall efficiency of 90.3% occur at the load transition resistance R. Bat =5Ω. Therefore, the system achieves optimal power transfer and energy conversion efficiency at the load transition resistance. When the system operates in CVO mode, the output power and overall efficiency of the system continuously decrease as the battery equivalent load increases. This is because, with the continuous increase of the equivalent load resistance, E # Branch line unloaded losses increase, leading to a continuous decrease in efficiency.

[0121] Figure 23 The loss distribution of each part of the experimental system is shown. The largest loss component is the magnetic coupling mechanism, accounting for approximately 45.3% of the total loss, mainly due to copper losses in the winding coils and iron losses in the magnetic core. This is followed by the rectifier bridge and the receiver compensation circuit, accounting for 26.8% and 13.2% of the total loss, respectively. The single-transistor inverter section accounts for only 8.2% of the total loss, due to the system's good soft-switching characteristics in both CCO and CVO modes, where losses are mainly due to the conduction losses of the switching transistors. Other losses account for approximately 6.5% of the total loss, mainly including power consumption in the control circuit and ohmic losses in the wires.

[0122] Table 5 shows a comparison of the system output characteristics under different compensation structures at the receiver. When E # When both the Class-E and Class-E branches use parallel compensation at their corresponding receivers, the system output exhibits constant current characteristics, functioning as a constant current source externally; when E # When both the Class-E and Class-E branches use series compensation at their corresponding receivers, the system output exhibits constant voltage characteristics, functioning as a constant voltage source externally. When E # When parallel compensation is used at the receiving end of the Class-E branch and series compensation is used at the receiving end of the Class-E branch, the system exhibits a constant voltage followed by a constant current output characteristic; when E # When the receiver of the branch uses series compensation and the receiver of the Class-E branch uses parallel compensation, the system exhibits a constant current and then constant voltage output characteristic, which meets the dynamic charging requirements of the device.

[0123] Table 5 Comparison of output characteristics of different receiver compensation structures

[0124]

[0125] In summary, this invention proposes a constant current and constant voltage self-switching dynamic wireless power transfer system with a hybrid topology of dual-winding T-type coils and single tubes. Based on theoretical analysis and simulation results, the following conclusions are drawn:

[0126] 1) Single-transistor hybrid compensation topology circuit via E # The circuit's constant current characteristics and Class-E constant voltage characteristics enable a dynamic wireless charging method that combines constant current with constant voltage, eliminating the need for additional detection circuits and allowing for adaptive switching between constant current and constant voltage.

[0127] 2) The transmitting coil of the dual-winding T-type coil magnetic coupling mechanism is orthogonally wound, which effectively cancels the coupling relationship between the two sets of coils. At the same time, the combination design of horizontal, 30° and 90° ferrite placement achieves the uniformity of magnetic field density distribution, which improves the transmission efficiency and anti-offset performance of the DWPT system.

[0128] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology, characterized in that: The transmitter includes a first inductor L1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a switching transistor Q1, and a first transmitting coil L. p1 Second transmitting coil L p1 The first inductor L1, the second capacitor C2, and the switching transistor Q1 are connected in series between the positive and negative terminals of the input DC voltage source DC. The first transmitting coil L... p1 The first capacitor C1 is connected in series between the common terminal of the first inductor L1 and the second capacitor C2 and the negative terminal of the input DC voltage source DC. The third capacitor C3 and the second transmitting coil L... p2 The first inductor L1, the second capacitor C2, and the first transmitting coil L are connected in series between the common terminal of the second capacitor C2 and the switching transistor Q1 and the negative terminal of the input DC voltage source DC. p1 The switching transistor Q1 and the first capacitor C1 constitute E. # The circuit consists of a first inductor L1, a switching transistor Q1, a second capacitor C2, a third capacitor C3, and a second transmitting coil L. p2 To form a Class-E circuit.

2. The constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology according to claim 1, characterized in that: Includes a receiving end, the receiving end including a first receiving coil L s1 Second receiving coil L s2 , with the first receiving coil L s1 Series compensation capacitor C s1 , and the second receiving coil L s2 Parallel compensation capacitor C s2 Connect the first receiving coil L s1 and series compensation capacitor C s1 The first rectifier circuit is connected to the second receiving coil L. s2 and parallel compensation capacitor C s2 The second rectifier circuit has a filter capacitor C connected in parallel with both the first and second rectifier circuits. O and parallel-connected filter capacitor C O The storage battery.

3. The constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology according to claim 2, characterized in that: E # The second capacitor C2 in the circuit is equivalent to C a and C b Two capacitors are connected in parallel, where capacitor C b and inductor L p1 To form a parallel resonance, capacitor C3 and inductor L in a Class-E circuit p2 A series resonance is formed, and the system's resonant angular frequency is... The inductor and capacitor parameters satisfy: ， in, For the second transmitting coil L p2 and the second receiving coil L s2 Mutual induction when facing each other.

4. The constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology according to claim 3, characterized in that: The system includes a transmitting mechanism, which comprises a transmitting ferrite core and a first transmitting coil L wound around the transmitting ferrite core. p1 and the second transmitting coil L p2 The transmitting ferrite includes a rectangular body, an oblique plate disposed at one end of the rectangular body in the horizontal direction forming an acute angle with the rectangular body, and two vertical plates disposed at both ends of the rectangular body in the vertical direction forming a right angle with the rectangular body; the first transmitting coil L p1 The second transmitting coil L p2 One horizontal winding and one vertical winding are applied to the rectangular body, with the horizontal and vertical directions arranged at equal intervals but not uniformly.

5. The constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology according to claim 4, characterized in that: The longitudinally wound transmitting coil has a density that decreases from the outer end to the inner end, and the coil spacing is an arithmetic sequence with a tolerance of d1. It is wound only on half of the rectangular body, adjacent to the oblique plate.

6. The constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology according to claim 5, characterized in that: The transversely wound transmitting coils exhibit a relatively symmetrical pattern with denser ends and a sparser middle, and the coil spacing is an arithmetic sequence with a tolerance of d2.

7. The constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology according to claim 6, characterized in that: The transmitting mechanism includes a receiving mechanism, and the transmitting mechanism includes a receiving ferrite core and a first receiving coil L wound around the receiving ferrite core. s1 Second receiving coil L s2 The first receiving coil L s1 The second receiving coil L s2 One horizontal winding and one vertical winding together form an orthogonal, uniform grid on the square receiving ferrite.

8. The constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology according to claim 7, characterized in that: The longitudinally wound transmitting coil serves as the first transmitting coil L. p1 The transversely wound transmitting coil serves as the second transmitting coil L. p2 The longitudinally wound receiving coil serves as the first transmitting coil L p1 The first receiving coil L coupled s1 The transversely wound receiving coil serves as the second transmitting coil L p2 The coupled second receiving coil L s2 .

9. The constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology according to claim 8, characterized in that, The parameters of the transmitting mechanism and the receiving mechanism are designed using the following steps: The dimensions of the receiver ferrite, the rectangular body, and the charging air gap are determined according to application requirements. With the goal of maximizing the ratio of the coupling coefficient after the magnetic coupling mechanism is offset laterally to that when it is aligned, the height H of the vertical piece, the number of turns N1 of the longitudinally wound transmitting coil and its coil spacing tolerance d1 are determined on the basis that the total length L of the longitudinally wound transmitting coil is less than half the length of the receiving end ferrite. The number of turns N2 of the transversely wound transmitting coil and its coil spacing tolerance d2 are determined with the goal of maximizing the ratio of the coupling coefficient after longitudinal offset of the magnetic coupling mechanism to that when it is aligned.

10. The constant current and constant voltage self-switching dynamic wireless power transfer system based on hybrid topology according to any one of claims 2 to 9, characterized in that: The threshold at which the system's operating mode switches is the critical load resistance. The corresponding load point, The operating angular frequency of the system. For the first transmitting coil L p1 and the first receiving coil L s1 Mutual inductance when facing each other; when the battery load equivalent resistance R Bat <R T At this time, E # The circuit and the Class-E circuit provide complementary power output, and the system operates in constant current output mode; when R Bat >R T At this time, E # When the circuit is blocked, its output is open, the Class-E circuit works normally, and the system operates in constant voltage output mode.

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