A high-voltage, low-voltage battery dual-frequency decoupling wireless charging system and method

Abstract

The application discloses a high-voltage and low-voltage battery dual-frequency decoupling wireless charging system and method, and relates to the technical field of wireless power transmission.The wireless charging system comprises a high-frequency inverter module, a primary side compensation structure, a transmitting coil, a receiving coil, a high-voltage side compensation branch, a low-voltage side compensation branch, a high-voltage side rectification filter module and a low-voltage side rectification filter module.The high-frequency inverter module is connected with the transmitting coil through the primary side compensation structure, the transmitting coil is magnetically coupled with the receiving coil, and the high-voltage side compensation branch and the low-voltage side compensation branch are connected with a high-voltage side load and a low-voltage side load through corresponding rectification filter modules.The wireless charging system and method can realize decoupling wireless power supply and independent charging control of the high-voltage side load and the low-voltage side load, reduce the use of receiving side coil and branch switching switch devices, simplify the magnetic coupling structure and the charging control mode, and improve the integration and operation reliability of the high / low-voltage battery wireless charging system.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission technology, specifically to a dual-frequency decoupled wireless charging system and method for high-voltage and low-voltage batteries. Background Technology

[0002] With the continuous development of wireless power transfer technology in electric vehicles and multi-power systems, these systems typically employ both high-voltage and low-voltage batteries. The high-voltage battery primarily powers the drive system, while the low-voltage battery supplies power to control units, auxiliary equipment, and low-voltage electronic loads. Therefore, achieving independent, safe, and stable charging of both high-voltage and low-voltage batteries is a crucial technical challenge in multi-voltage wireless charging systems.

[0003] Existing wireless power transfer systems still have shortcomings in charging batteries at multiple voltage levels. First, in some systems, the charging processes of high-voltage and low-voltage batteries are difficult to decouple effectively. When powering the high-voltage battery, the low-voltage battery may be forced to charge simultaneously, easily leading to overcharging risks and safety hazards. Second, to achieve independent control of high / low-voltage batteries, some solutions require the introduction of AC switches, relays, or additional compensation branches to achieve energy distribution by switching different charging paths. This not only increases system complexity and control difficulty, but also may subject the switching devices to significant induced voltage stress, reducing system reliability. Third, some multi-output wireless power supply solutions require strict design constraints on the magnetic coupling mechanism, or the introduction of multiple sets of magnetic coupling mechanisms to achieve multi-path power supply, resulting in increased system size, weight, cost, and design complexity.

[0004] Therefore, it is necessary to propose a wireless charging system and method that does not require additional AC switches or multiple sets of magnetic coupling mechanisms, and can selectively activate the high-voltage or low-voltage output branches based on the operating frequency, so as to realize independent and controllable charging of high-voltage and low-voltage batteries, improve system reliability and engineering application value. Summary of the Invention

[0005] The purpose of this invention is to propose a dual-frequency decoupled wireless charging system and method for high-voltage and low-voltage batteries, which can realize decoupled wireless power supply and independent charging control of high-voltage side load and low-voltage side load, reduce the use of receiving side coil and branch switching devices, simplify magnetic coupling structure and charging control method, and improve the integration and operational reliability of high / low voltage battery wireless charging system.

[0006] The technical solution adopted in this invention is: a dual-frequency decoupled wireless charging system for high-voltage and low-voltage batteries, comprising a high-frequency inverter module, a primary-side compensation structure, a transmitting coil, a receiving coil, a high-voltage side compensation branch, a low-voltage side compensation branch, a high-voltage side rectification and filtering module, and a low-voltage side rectification and filtering module. The high-frequency inverter module is connected to the transmitting coil via the primary-side compensation structure. The transmitting coil is magnetically coupled to the receiving coil. The high-voltage side compensation branch and the low-voltage side compensation branch are respectively connected to the high-voltage side load and the low-voltage side load via corresponding rectification and filtering modules. The high-voltage side compensation branch and the low-voltage side compensation branch are connected in parallel in the stage following the same receiving coil; The high-voltage side compensation branch and the low-voltage side compensation branch each include three compensation capacitors and two compensation inductors, and both have the same compensation topology but different compensation parameters. The high-frequency inverter module is configured to switch between outputting high-frequency AC excitation between a first operating frequency and a second operating frequency. The compensation parameters of the primary-side compensation structure, the high-voltage side compensation branch, and the low-voltage side compensation branch are configured collaboratively according to the first operating frequency and the second operating frequency, such that: At the first operating frequency, the high-voltage side compensation branch is in the energy transmission state, and the low-voltage side compensation branch is in the detuning suppression state. At the second operating frequency, the low-voltage side compensation branch is in the energy transmission state, and the high-voltage side compensation branch is in the detuning suppression state.

[0007] As a preferred embodiment, the primary-side compensation structure has a first primary-side port and a second primary-side port that are respectively connected to the two output terminals of the high-frequency inverter module; The first primary-side port is connected to one end of the first primary-side compensating inductor; The other end of the first primary-side compensating inductor is connected to one end of the first primary-side compensating capacitor; The other end of the first primary-side compensation capacitor is connected to the first primary-side node; The first primary-side node is connected to one end of the second primary-side compensation capacitor, one end of the second primary-side compensation inductor, and one end of the third primary-side compensation capacitor, respectively. The other end of the second primary-side compensation capacitor, the other end of the second primary-side compensation inductor, and one end of the transmitting coil are all connected to the second primary-side port; The other end of the third primary-side compensation capacitor is connected to the other end of the transmitting coil.

[0008] As a preferred embodiment, the high-voltage side compensation branch and the low-voltage side compensation branch have the same compensation topology, and each of the compensation branches includes a first branch compensation capacitor, a second branch compensation capacitor, a third branch compensation capacitor, a first branch compensation inductor, and a second branch compensation inductor. One end of the receiving coil is connected to one end of the third branch compensation capacitor and the first AC input terminal of the corresponding rectifier and filter module, and the other end of the receiving coil is connected to the first compensation node via the first branch compensation capacitor. The first compensation node is connected to one end of the first branch compensation inductor and one end of the second branch compensation capacitor, respectively. The other end of the first branch compensation inductor, the other end of the second branch compensation capacitor, the other end of the third branch compensation capacitor, and one end of the second branch compensation inductor are connected to the second compensation node. The other end of the second branch compensation inductor is connected to the second AC input terminal of the rectifier filter module.

[0009] As a preferred embodiment, at the first operating frequency, the high-voltage side compensation branch achieves constant current output, and the output current of the low-voltage side compensation branch is suppressed to near zero. At the second operating frequency, the low-voltage side compensation branch achieves constant current output, and the output current of the high-voltage side compensation branch is suppressed to near zero.

[0010] As a preferred embodiment, the compensation parameters of the primary-side compensation structure, the high-voltage side compensation branch, and the low-voltage side compensation branch are further configured to ensure that the system meets the zero-phase angle input condition at the first operating frequency and the second operating frequency.

[0011] As a preferred embodiment, the high-frequency inverter module is a full-bridge inverter circuit, a half-bridge inverter circuit, a Class-D inverter circuit, or a Class-E inverter circuit.

[0012] As a preferred embodiment, the high-voltage side rectifier and filter module and the low-voltage side rectifier and filter module are respectively a diode rectifier and filter circuit, an active rectifier and filter circuit, or a synchronous rectifier and filter circuit.

[0013] As a preferred embodiment, when the system operates at the first operating frequency, the primary-side compensation structure, the high-voltage side compensation branch, and the low-voltage side compensation branch satisfy the following parameter relationships:

[0014] Furthermore, when zero phase angle input is satisfied at the first operating frequency, the primary-side compensation structure and the high-voltage-side compensation branch further satisfy the following parameter relationship:

[0015] In the formula, ω1=2πf1 is the operating angular frequency corresponding to the operating frequency f1; L p1 L p2 These represent the inductance values ​​of the first primary-side compensating inductor and the second primary-side compensating inductor, respectively; L p3 L represents the self-inductance of the transmitting coil. s1 L represents the self-inductance of the receiving coil. s2 L s3 These represent the inductance values ​​of the first and second branch compensation inductors in the high-voltage side compensation circuit, respectively; L s4 This represents the inductance value of the compensation inductor in the first branch of the low-voltage side compensation circuit; C p1 C p2 C p3 These represent the capacitance values ​​of the first primary-side compensation capacitor, the second primary-side compensation capacitor, and the third primary-side compensation capacitor, respectively; C s1 C s2 C s3 These represent the capacitance values ​​of the first, second, and third branch compensation capacitors in the high-voltage side compensation circuit, respectively; C s5 This indicates the capacitance value of the compensation capacitor in the second branch of the low-voltage side compensation branch.

[0016] As a preferred embodiment, when the system operates at the second operating frequency, the primary-side compensation structure, the high-voltage side compensation branch, and the low-voltage side compensation branch satisfy the following parameter relationships:

[0017] Furthermore, when zero phase angle input is satisfied at the second operating frequency, the primary-side compensation structure and the low-voltage-side compensation branch further satisfy the following parameter relationship:

[0018] In the formula, ω2=2πf2 is the operating angular frequency corresponding to the operating frequency f2; L s5 This represents the inductance value of the compensation inductor in the second branch of the low-voltage side compensation circuit; C s4 C s6 These represent the capacitance values ​​of the first and third branch compensation capacitors in the low-voltage side compensation circuit, respectively.

[0019] A dual-frequency decoupled wireless charging method for high-voltage and low-voltage batteries is applied to a wireless charging system comprising a high-frequency inverter module, a primary-side compensation structure, mutually magnetically coupled transmitting and receiving coils, a high-voltage side compensation branch, a low-voltage side compensation branch, a high-voltage side rectifier and filter module, and a low-voltage side rectifier and filter module. The high-voltage side compensation branch and the low-voltage side compensation branch are respectively connected to the high-voltage side load and the low-voltage side load via corresponding rectifier and filter modules. The method includes: The high-voltage side compensation branch and the low-voltage side compensation branch, each comprising three compensation capacitors and two compensation inductors, are connected in parallel in the stage following the same receiving coil, and the high-voltage side compensation branch and the low-voltage side compensation branch have the same compensation topology and different compensation parameters. Based on the first operating frequency and the second operating frequency, the compensation parameters of the primary side compensation structure, the high-voltage side compensation branch and the low-voltage side compensation branch are coordinated and configured so that the high-voltage side compensation branch and the low-voltage side compensation branch form mutually exchanging energy transfer state and detuning suppression state at the first operating frequency and the second operating frequency. When wirelessly charging the high-voltage side load, the high-frequency inverter module is controlled to output high-frequency AC excitation at the first operating frequency, so that the high-voltage side compensation branch is in the energy transmission state and the low-voltage side compensation branch is in the detuning suppression state. When wirelessly charging the low-voltage side load, the output frequency of the high-frequency inverter module is switched from the first operating frequency to the second operating frequency, so that the low-voltage side compensation branch is in the energy transmission state and the high-voltage side compensation branch is in the detuning suppression state.

[0020] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses a dual-frequency control mechanism to selectively activate corresponding output branches at different operating frequencies, thereby achieving independent charging and effective decoupling of the high-voltage battery and the low-voltage battery, avoiding mutual interference and overcharging problems.

[0021] 2. This invention does not require the introduction of AC switches, relays or additional switching circuits. It can achieve selective operation of different output branches simply by designing frequency switching and compensation parameters, thereby reducing system complexity and improving operational reliability.

[0022] 3. This invention can achieve dual output function by using a magnetic coupling structure with a single transmitting coil and a single receiving coil, without the need for multiple sets of magnetic coupling mechanisms or complex magnetic coupling design constraints, which is beneficial to improving the system power density and integration.

[0023] 4. Through the design of compensation parameters, this invention enables both the high-voltage side and the low-voltage side to have constant current output capability at the corresponding operating frequency, which is beneficial to the safe charging of the battery and the control of the charging process.

[0024] 5. This invention has good designability and scalability, and the compensation parameters can be optimized according to different voltage levels, battery capacities and power requirements. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is the equivalent circuit diagram of the high / low voltage battery dual-frequency decoupled wireless charging system of the present invention; Figure 2 In one embodiment of the present invention, under the condition that the coupling coefficient is 0.1732, the high-voltage side output current varies with the load R. H The changing characteristic curve; Figure 3 In one embodiment of the present invention, with a coupling coefficient of 0.1732, the low-voltage side output current varies with the load R. L The changing characteristic curve; Figure 4 In one embodiment of the present invention, under the condition that the coupling coefficient is 0.3464, the high-voltage side output current varies with the load R. H The changing characteristic curve; Figure 5 In one embodiment of the present invention, with a coupling coefficient of 0.3464, the low-voltage side output current varies with the load R. L The changing characteristic curve. Detailed Implementation

[0027] The present invention will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0028] It should be noted that, unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "a," "an," or "the," etc., used in the specification and claims of this patent application do not express a limitation on quantity, but rather indicate the presence of at least one; the terms "first," "second," and "third," as used herein, should not be considered as a limitation on the order of components, but are merely for distinguishing different components; the terms "comprising," "including," etc., indicate that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects having the same function.

[0029] To more clearly describe the high-voltage and low-voltage battery dual-frequency decoupled wireless charging system and method, see the attached document. Figure 1-5 Description of the embodiment: like Figure 1 As shown, a dual-frequency decoupled wireless charging system for high-voltage and low-voltage batteries includes a DC source U. DC High-frequency inverter module, primary-side compensation structure, transmitting coil L p3 Receiver coil L s1 High-voltage side compensation branch, low-voltage side compensation branch, high-voltage side rectifier and filter module, low-voltage side rectifier and filter module, high-voltage side load R H and low-voltage side load R L ;I H I L These represent the high-voltage side output current and the low-voltage side output current, respectively.

[0030] DC source U DC Used to provide DC input power to the high-frequency inverter module.

[0031] The high-frequency inverter module is used to output a switchable high-frequency AC excitation, with its output frequencies including a first operating frequency f1 and a second operating frequency f2, which can be switched. The high-frequency inverter module can be a full-bridge inverter circuit, a half-bridge inverter circuit, a Class-D inverter circuit, a Class-E inverter circuit, or other inverter circuits capable of providing high-frequency AC excitation to the primary-side compensation structure. The focus of this invention is on the design of the primary-side compensation structure, the high-voltage side compensation branch, the low-voltage side compensation branch, and their dual-frequency decoupling parameters. The specific number of switching devices, connection method, and driving method of the high-frequency inverter module are determined according to actual requirements.

[0032] The high-frequency inverter module is connected to the transmitting coil L via the primary-side compensation structure. p3 Connection, transmitting coil L p3 With receiving coil L s1 Magnetic coupling, the high-voltage side compensation branch and the low-voltage side compensation branch are respectively connected to the high-voltage side load R via corresponding rectifier and filter modules. H and low-voltage side load R L connect.

[0033] The primary-side compensation structure is connected to the output terminal of the high-frequency inverter module. The primary-side compensation structure has a first primary-side port and a second primary-side port. The first primary-side port is connected to the first primary-side compensation inductor L. p1 One end is connected; the first primary-side compensating inductor L p1 The other end is connected to the first primary-side compensation capacitor C p1 One end is connected; the first primary-side compensation capacitor C p1 The other end is connected to the first primary edge node; the first primary edge node is connected to the second primary edge compensation capacitor C. p2 One end, the second primary-side compensating inductor L p2One end and the third primary-side compensation capacitor C p3 One end is connected; the second primary-side compensation capacitor C p2 The other end, the second primary-side compensating inductor L p2 The other end and the transmitting coil L p3 One end of each capacitor is connected to the second primary side port; the third primary side compensation capacitor C p3 The other end is connected to the transmitting coil L p3 The other end is connected.

[0034] transmitting coil L p3 With receiving coil L s1 Energy transfer is achieved through magnetic field coupling, and the mutual inductance between the two is M. The high-voltage side compensation branch and the low-voltage side compensation branch are connected in parallel on the same receiving coil L. s1 The subsequent stage, and sharing the same receiving coil L s1 .

[0035] The high-voltage side compensation branch and the low-voltage side compensation branch each include three compensation capacitors and two compensation inductors, and both have the same compensation topology but different compensation parameters. In this embodiment, for the high-voltage side compensation branch, the compensation capacitors of the first branch, the second branch, and the third branch, and the compensation inductors of the first and second branches are C0, respectively. s1 C s2 C s3 L s2 and L s3 For the low-voltage side compensation branch, the compensation capacitors of the first branch, the second branch, and the third branch, and the compensation inductors of the first and second branches are respectively C s4 C s5 C s6 L s4 and L s5 .

[0036] The high-voltage side compensation branch is connected to the receiving coil L. s1 Between it and the high-voltage side rectifier and filter module. Receiving coil L s1 One end is connected to the third high-voltage side compensation capacitor C. s3 One end is connected to the first AC input terminal of the high-voltage side rectifier and filter module; the receiving coil L s1 The other end is connected to the first high-voltage side compensation capacitor C s1 One end is connected; the first high-voltage side compensation capacitor C s1 The other end is connected to the first high-voltage side node; the first high-voltage side node is connected to the first high-voltage side compensation inductor L. s2 One end and the second high-voltage side compensation capacitor C s2 One end is connected; the first high-voltage side compensation inductor L s2The other end, the second high-voltage side compensation capacitor C s2 The other end, the third high-voltage side compensation capacitor C s3 The other end and the second high-voltage side compensation inductor L s3 One end is connected to the second high-voltage side node; the second high-voltage side compensation inductor L s3 The other end is connected to the second AC input terminal of the high-voltage side rectifier and filter module. The high-voltage side rectifier and filter module converts the AC power output from the high-voltage side compensation branch into DC power and supplies it to the high-voltage side load R. H powered by.

[0037] The low-voltage side compensation branch is connected to the receiving coil L. s1 Between the low-voltage side rectifier and filter module. Receiving coil L s1 One end is connected to the third low-voltage side compensation capacitor C. s6 One end is connected to the first AC input terminal of the low-voltage side rectifier and filter module; the receiving coil L s1 The other end is connected to the first low-voltage side compensation capacitor C s4 One end is connected; the first low-voltage side compensation capacitor C s4 The other end is connected to the first low-voltage side node; the first low-voltage side node is connected to the first low-voltage side compensation inductor L. s4 One end and the second low-voltage side compensation capacitor C s5 One end is connected; the first low-voltage side compensation inductor L s4 The other end, the second low-voltage side compensation capacitor C s5 The other end, the third low-voltage side compensation capacitor C s6 The other end and the second low-voltage side compensation inductor L s5 One end is connected to the second low-voltage side node; the second low-voltage side compensation inductor L s5 The other end is connected to the second AC input terminal of the low-voltage side rectifier and filter module. The low-voltage side rectifier and filter module converts the AC power output from the low-voltage side compensation branch into DC power and supplies it to the low-voltage side load R. L powered by.

[0038] The high-voltage side rectifier and filter module and the low-voltage side rectifier and filter module can adopt diode rectifier and filter circuits, active rectifier and filter circuits, synchronous rectifier and filter circuits or other AC-DC converter circuits, and their specific structures are not limited.

[0039] In this embodiment, the system has two operating frequencies: a first operating frequency f1 and a second operating frequency f2. The compensation parameters of the primary-side compensation structure, the high-voltage side compensation branch, and the low-voltage side compensation branch are configured collaboratively according to the first and second operating frequencies, such that: when the high-frequency inverter module output frequency is f1, the high-voltage side compensation branch participates in energy transfer and achieves constant current output, while the low-voltage side compensation branch is suppressed; when the high-frequency inverter module output frequency is f2, the low-voltage side compensation branch participates in energy transfer and achieves constant current output, while the high-voltage side compensation branch is suppressed. Thus, the system achieves independent charging and decoupling control of the high-voltage and low-voltage sides through frequency selection.

[0040] It should be noted that, for ease of description, the same symbols are used in this article to represent the corresponding inductor, capacitor and their parameters; in the circuit structure description, the symbols represent the corresponding inductor or capacitor; in the following parameter relationships and calculations, the symbols represent the inductance value of the corresponding inductor or the capacitance value of the corresponding capacitor; wherein, the symbols corresponding to the transmitting coil and the receiving coil represent the self-inductance value of the corresponding coil in the parameter relationships and calculations.

[0041] When the system operates at the first operating frequency f1, in order to achieve constant current output in the high-voltage side compensation branch and keep the low-voltage side compensation branch in a non-operating state (detuning suppression state), the parameters of the primary-side compensation structure, the high-voltage side compensation branch, and the low-voltage side compensation branch must satisfy:

[0042] In the formula: ω1=2πf1 is the operating angular frequency corresponding to the operating frequency f1.

[0043] Based on the above conditions, in order to further achieve zero-phase angle input, the primary-side compensation structure and the high-voltage-side compensation branch also need to satisfy:

[0044] When the system operates at the second operating frequency f2, in order to achieve constant current output in the low-voltage side compensation branch and keep the high-voltage side compensation branch in a non-operating state (detuning suppression state), the parameters of the primary-side compensation structure, the high-voltage side compensation branch, and the low-voltage side compensation branch must satisfy:

[0045] In the formula: ω2=2πf2 is the operating angular frequency corresponding to the operating frequency f2.

[0046] Based on the above conditions, in order to further achieve zero-phase angle input, the primary-side compensation structure and the low-voltage-side compensation branch also need to satisfy:

[0047] Furthermore, given the above parameter relationships, when the system operates at the first operating frequency f1, the transconductance gain G1 on the high-voltage side can be expressed as:

[0048] in, The primary side input AC voltage, M represents the equivalent AC output current on the high-voltage side, and L represents the transmitting coil. p3 With receiving coil L s1 Mutual inductance value.

[0049] When the system operates at the second operating frequency f2, the transconductance gain G2 on the low-voltage side can be expressed as:

[0050] in, This is the equivalent AC output current on the low-voltage side.

[0051] The transconductance gain described above is used to explain the theoretical basis for the system of the present invention to achieve constant current output on the high-voltage side and constant current output on the low-voltage side at two operating frequencies, respectively. The transconductance gain formula can be used for example analysis and parameter selection.

[0052] The following provides a set of parameters for a specific embodiment. In this embodiment, the first operating frequency f1 is 85.0 kHz, the second operating frequency f2 is 267.4 kHz, and the coupling coefficients k are 0.1732 and 0.3464, respectively. The parameters of each compensation element are shown in Table 1.

[0053] Table 1 System parameter settings

[0054] Figure 2 The diagram shows the output current on the high-voltage side as a function of the load R when the coupling coefficient is 0.1732 and the operating frequency is f1. H The characteristic curve shows the change. As can be seen from the graph, with the load R... H The high-voltage side output current remained relatively stable at around 8.0 A, exhibiting good constant current output characteristics. Meanwhile, the low-voltage side output current was close to 0 A, indicating that only the high-voltage side formed an effective energy transmission channel at this frequency, while the low-voltage side was suppressed.

[0055] Figure 3 The diagram shows the output current on the low-voltage side as a function of the load R when the coupling coefficient is 0.1732 and the operating frequency is f2. L The characteristic curve shows the change. As can be seen from the graph, with the load R... LThe output current on the low-voltage side remained relatively stable at around 1.4 A, exhibiting good constant current output characteristics. Meanwhile, the output current on the high-voltage side was close to 0 A, indicating that only the low-voltage side formed an effective energy transmission channel at this frequency, while the high-voltage side was suppressed.

[0056] Figure 4 The diagram shows the output current on the high-voltage side as a function of the load R when the coupling coefficient is 0.3464 and the operating frequency is f1. H The characteristic curves show that the high-voltage side output current remains relatively stable at around 16.0 A, while the low-voltage side output current is close to 0 A. This indicates that the system maintains good decoupling characteristics between the high and low voltage sides even with a large coupling coefficient.

[0057] Figure 5 The diagram shows the output current on the low-voltage side as a function of the load R when the coupling coefficient is 0.3464 and the operating frequency is f2. L The characteristic curves show that the low-voltage side output current remains relatively stable at around 2.8 A, while the high-voltage side output current is close to 0 A. This indicates that the system can still achieve constant current output on the low-voltage side and suppression on the high-voltage side even with a large coupling coefficient.

[0058] As can be seen from the above embodiments, the present invention achieves selective constant current output on the high-voltage and low-voltage sides at different operating frequencies through a single transmitting coil, a single receiving coil, and two sets of parallel compensation branches for high and low voltage. The system can achieve independent charging of high-voltage and low-voltage batteries without the need for additional AC switches, multiple sets of magnetic coupling mechanisms, or complex switching controls, and has high reliability, integration, and engineering application value.

[0059] It should be noted that although the present invention has been described through the above embodiments, the present invention may have many other embodiments. Without departing from the spirit and scope of the present invention, those skilled in the art can obviously make various corresponding changes and modifications to the present invention, but all such changes and modifications should fall within the scope of protection of the appended claims and their equivalents.

Claims

1. A dual-frequency decoupled wireless charging system for high-voltage and low-voltage batteries, characterized in that: The system includes a high-frequency inverter module, a primary-side compensation structure, a transmitting coil, a receiving coil, a high-voltage side compensation branch, a low-voltage side compensation branch, a high-voltage side rectification and filtering module, and a low-voltage side rectification and filtering module. The high-frequency inverter module is connected to the transmitting coil via the primary-side compensation structure. The transmitting coil is magnetically coupled to the receiving coil. The high-voltage side compensation branch and the low-voltage side compensation branch are respectively connected to the high-voltage side load and the low-voltage side load via their respective rectification and filtering modules. The high-voltage side compensation branch and the low-voltage side compensation branch are connected in parallel in the stage following the same receiving coil; The high-voltage side compensation branch and the low-voltage side compensation branch each include three compensation capacitors and two compensation inductors, and both have the same compensation topology but different compensation parameters. The high-frequency inverter module is configured to switch between outputting high-frequency AC excitation between a first operating frequency and a second operating frequency. The compensation parameters of the primary-side compensation structure, the high-voltage side compensation branch, and the low-voltage side compensation branch are configured collaboratively according to the first operating frequency and the second operating frequency, such that: At the first operating frequency, the high-voltage side compensation branch is in the energy transmission state, and the low-voltage side compensation branch is in the detuning suppression state. At the second operating frequency, the low-voltage side compensation branch is in the energy transmission state, and the high-voltage side compensation branch is in the detuning suppression state.

2. The system according to claim 1, characterized in that: The primary-side compensation structure has a first primary-side port and a second primary-side port that are respectively connected to the two output terminals of the high-frequency inverter module. The first primary-side port is connected to one end of the first primary-side compensating inductor; The other end of the first primary-side compensating inductor is connected to one end of the first primary-side compensating capacitor; The other end of the first primary-side compensation capacitor is connected to the first primary-side node; The first primary-side node is connected to one end of the second primary-side compensation capacitor, one end of the second primary-side compensation inductor, and one end of the third primary-side compensation capacitor, respectively. The other end of the second primary-side compensation capacitor, the other end of the second primary-side compensation inductor, and one end of the transmitting coil are all connected to the second primary-side port; The other end of the third primary-side compensation capacitor is connected to the other end of the transmitting coil.

3. The system according to claim 2, characterized in that: The high-voltage side compensation branch and the low-voltage side compensation branch have the same compensation topology. Each of the compensation branches includes a first branch compensation capacitor, a second branch compensation capacitor, a third branch compensation capacitor, a first branch compensation inductor, and a second branch compensation inductor. One end of the receiving coil is connected to one end of the third branch compensation capacitor and the first AC input terminal of the corresponding rectifier and filter module, and the other end of the receiving coil is connected to the first compensation node via the first branch compensation capacitor. The first compensation node is connected to one end of the first branch compensation inductor and one end of the second branch compensation capacitor, respectively. The other end of the first branch compensation inductor, the other end of the second branch compensation capacitor, the other end of the third branch compensation capacitor, and one end of the second branch compensation inductor are connected to the second compensation node. The other end of the second branch compensation inductor is connected to the second AC input terminal of the rectifier and filter module.

4. The system according to claim 1, characterized in that: At the first operating frequency, the high-voltage side compensation branch achieves constant current output, and the output current of the low-voltage side compensation branch is suppressed to near zero. At the second operating frequency, the low-voltage side compensation branch achieves constant current output, and the output current of the high-voltage side compensation branch is suppressed to near zero.

5. The system according to claim 3, characterized in that: The compensation parameters of the primary-side compensation structure, the high-voltage side compensation branch, and the low-voltage side compensation branch are further configured to ensure that the system meets the zero-phase angle input condition at the first operating frequency and the second operating frequency.

6. The system according to claim 1, characterized in that: The high-frequency inverter module is a full-bridge inverter circuit, a half-bridge inverter circuit, a Class-D inverter circuit, or a Class-E inverter circuit.

7. The system according to claim 1, characterized in that: The high-voltage side rectifier and filter module and the low-voltage side rectifier and filter module are respectively a diode rectifier and filter circuit, an active rectifier and filter circuit, or a synchronous rectifier and filter circuit.

8. The system according to claim 5, characterized in that, When the system operates at the first operating frequency, the primary-side compensation structure, the high-voltage side compensation branch, and the low-voltage side compensation branch satisfy the following parameter relationship: Furthermore, when zero phase angle input is satisfied at the first operating frequency, the primary-side compensation structure and the high-voltage-side compensation branch further satisfy the following parameter relationship: In the formula, ω1=2πf1 is the operating angular frequency corresponding to the operating frequency f1; L p1 L p2 These represent the inductance values ​​of the first primary-side compensating inductor and the second primary-side compensating inductor, respectively; L p3 L represents the self-inductance of the transmitting coil. s1 L represents the self-inductance of the receiving coil. s2 L s3 These represent the inductance values ​​of the first and second branch compensation inductors in the high-voltage side compensation circuit, respectively; L s4 This represents the inductance value of the compensation inductor in the first branch of the low-voltage side compensation circuit; C p1 C p2 C p3 These represent the capacitance values ​​of the first primary-side compensation capacitor, the second primary-side compensation capacitor, and the third primary-side compensation capacitor, respectively; C s1 C s2 C s3 These represent the capacitance values ​​of the first, second, and third branch compensation capacitors in the high-voltage side compensation circuit, respectively; C s5 This indicates the capacitance value of the compensation capacitor in the second branch of the low-voltage side compensation branch.

9. The system according to claim 5, characterized in that, When the system operates at the second operating frequency, the primary-side compensation structure, the high-voltage side compensation branch, and the low-voltage side compensation branch satisfy the following parameter relationship: Furthermore, when zero phase angle input is satisfied at the second operating frequency, the primary-side compensation structure and the low-voltage-side compensation branch further satisfy the following parameter relationship: In the formula, ω2=2πf2 is the operating angular frequency corresponding to the operating frequency f2; L s5 This represents the inductance value of the compensation inductor in the second branch of the low-voltage side compensation circuit; C s4 C s6 These represent the capacitance values ​​of the first and third branch compensation capacitors in the low-voltage side compensation circuit, respectively.

10. A dual-frequency decoupled wireless charging method for high-voltage and low-voltage batteries, applied to a wireless charging system including a high-frequency inverter module, a primary-side compensation structure, mutually magnetically coupled transmitting and receiving coils, a high-voltage side compensation branch, a low-voltage side compensation branch, a high-voltage side rectifier and filter module, and a low-voltage side rectifier and filter module, wherein the high-voltage side compensation branch and the low-voltage side compensation branch are respectively connected to the high-voltage side load and the low-voltage side load via corresponding rectifier and filter modules, characterized in that... include: The high-voltage side compensation branch and the low-voltage side compensation branch, each comprising three compensation capacitors and two compensation inductors, are connected in parallel in the stage following the same receiving coil, and the high-voltage side compensation branch and the low-voltage side compensation branch have the same compensation topology and different compensation parameters. Based on the first operating frequency and the second operating frequency, the compensation parameters of the primary side compensation structure, the high-voltage side compensation branch and the low-voltage side compensation branch are coordinated and configured so that the high-voltage side compensation branch and the low-voltage side compensation branch form mutually exchanging energy transfer state and detuning suppression state at the first operating frequency and the second operating frequency. When wirelessly charging the high-voltage side load, the high-frequency inverter module is controlled to output high-frequency AC excitation at the first operating frequency, so that the high-voltage side compensation branch is in the energy transmission state and the low-voltage side compensation branch is in the detuning suppression state. When wirelessly charging the low-voltage side load, the output frequency of the high-frequency inverter module is switched from the first operating frequency to the second operating frequency, so that the low-voltage side compensation branch is in the energy transmission state and the high-voltage side compensation branch is in the detuning suppression state.

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