A kind of active and passive collaborative noise reduction high-power wireless charging system and control method thereof

Abstract

The application discloses a kind of active and passive collaborative noise reduction high-power wireless charging system and control method thereof.A kind of active and passive collaborative noise reduction high-power wireless charging system includes direct-current power supply, full-bridge inverter circuit, LCC-S resonant network, transmitting coil module, receiving coil module, rectification filter circuit and load module;The transmitting coil module is gradient damping potting coil module, the gradient damping potting coil module includes magnetic core, coil winding and the potting body that is covered in the magnetic core and the coil winding outside;The potting body is sequentially provided with first damping layer, second damping layer and outer layer heat conduction structure layer from inside to outside, three layers of structure are integrally cured and formed, form no-gap crosslinking integrated interface;The wireless charging system further includes magnetic flux limiting quiet control system, and the magnetic flux limiting quiet control system includes sampling unit, magnetic flux operation unit, control unit and inverter drive unit.The application is applied to the technical field of wireless charging.

Description

Technical Field

[0001] This invention is applied to the field of high-power wireless charging technology, specifically relating to a high-power wireless charging system and its control method with active and passive collaborative noise reduction suitable for industrial-grade high-power wireless charging scenarios of 2kW and above. It is mainly applied to fully automatic wireless charging scenarios for AGV handling robots, electric forklifts, construction machinery equipment, and industrial mobile terminals, and is especially suitable for noise reduction, heat dissipation, and efficiency optimization scenarios of high-power wireless charging equipment with LCC-S resonant topology. Background Technology

[0002] Industrial high-power wireless charging systems commonly employ an LCC-S resonant topology, with typical operating frequencies concentrated in the 10kHz–18kHz range. This frequency precisely covers the area of ​​human hearing sensitivity, making the devices prone to generating audible noise during operation. Research has revealed two independent yet superimposed vibration and noise excitation sources in high-power wireless charging coil modules: firstly, magnetostrictive vibration of the magnetic core, where the ferrite core undergoes periodic micro-deformation under the influence of a high-frequency alternating magnetic field, generating magnetostrictive vibration and radiating noise outwards, with the vibration energy concentrated within the core itself; secondly, electromagnetic jitter of the windings, where the Litz wires of the coil generate high-frequency micro-jitter between turns and layers under the influence of a large-current alternating electromagnetic force, with the vibration energy distributed between the coil wire gaps and the inter-turn gaps. The superposition of these two types of vibration significantly increases the system noise amplitude, with operating noise levels of 2kW and above typically reaching 55dB–65dB, failing to meet the low-noise operation requirements of industrial equipment.

[0003] Currently, the industry has developed two independent technical paths for noise reduction in wireless charging devices: structural noise reduction and control noise reduction. However, both have obvious technical defects and cannot achieve compatibility optimization.

[0004] In terms of structural noise reduction, existing conventional solutions mostly employ methods such as locally bonding vibration damping pads to the magnetic core or overall flexible potting. The locally applied vibration damping pad solution only weakens the transmission of vibration on the magnetic core surface and cannot suppress electromagnetic jitter in the windings, resulting in an overall noise reduction of less than 5dB, with extremely poor noise reduction effect. While the overall flexible potting solution can reduce overall vibration to some extent, the flexible damping material has poor thermal conductivity, leading to heat accumulation in the coil module during long-term high-power operation, causing excessive temperature rise and decreased operational stability. Some existing multi-layer potting patent technologies are simply stacks of soft and hard materials or multiple injections of the same material, without damping matching design for the two different vibration sources: magnetostrictive vibration and winding electromagnetic jitter, thus failing to simultaneously achieve noise reduction, heat dissipation, and structural stability.

[0005] In terms of noise reduction, mainstream solutions increase the inverter switching frequency to move the operating frequency away from the sensitive frequency range of the human ear. However, for every 1kHz increase in switching frequency, the switching losses of power devices increase by 3% to 5%, directly leading to a significant decrease in the overall charging efficiency. At the same time, existing current and power regulation solutions mainly aim to optimize transmission efficiency and improve offset tolerance, without designing dedicated noise reduction control logic for the source of magnetostrictive vibration in the magnetic core, thus failing to suppress noise generation at its root.

[0006] More importantly, in existing technologies, structural noise reduction and control noise reduction are completely isolated. Structural noise reduction only passively attenuates the vibration noise that has already been generated, and control noise reduction only passively avoids the frequency band that the human ear can perceive. There is no technical solution that can organically combine and synergistically optimize the two types of technologies. The industry has long held the technical prejudice that "noise reduction must sacrifice heat dissipation and noise reduction must reduce charging efficiency," which has become the core bottleneck restricting the development of low-noise and high-performance high-power industrial wireless charging equipment. Summary of the Invention

[0007] The technical problem this invention aims to solve is to overcome the shortcomings of existing technologies and provide a high-power wireless charging system and its control method with active and passive coordinated noise reduction. This addresses the issues of high noise levels, poor single-stage noise reduction effectiveness, and the mutual constraint between noise reduction and heat dissipation efficiency in existing high-power wireless charging devices. This invention achieves multi-level vibration attenuation through a passive gradient damping structure, suppresses vibration excitation at its source through active flux limiting control, and achieves a superimposed noise reduction effect through an active-passive coordinated mechanism. This significantly reduces device operating noise while ensuring that the system's heat dissipation performance and transmission efficiency are not compromised.

[0008] The technical solution adopted in this invention is as follows: This invention includes a high-power wireless charging system with active and passive coordinated noise reduction and its control method. The high-power wireless charging system with active and passive coordinated noise reduction includes a DC power supply, a full-bridge inverter circuit, an LCC-S resonant network, a transmitting coil module, a receiving coil module, a rectifier and filter circuit, and a load module. The transmitting coil module is a gradient damping potted coil module, which includes a magnetic core, a coil winding, and a potting body covering the magnetic core and the coil winding. The potting body is provided with a first damping layer, a second damping layer, and an outer thermal conductive structure layer from the inside out, forming a three-layer integrated structure. The process involves curing and molding to form a seamless, cross-linked, integrated interface. The first damping layer completely covers the entire outer surface of the magnetic core, serving to absorb magnetostrictive vibrations generated during high-frequency operation of the magnetic core through elastic viscous deformation buffering. The second damping layer completely fills the inter-turn gaps and wire gaps of the coil winding, serving to suppress inter-turn alternating electromagnetic jitter of the coil winding through flexible damping constraints. The outer thermally conductive structural layer provides overall structural support and an efficient heat dissipation channel for the coil module. The outer thermally conductive structural layer has a material hardness of not less than Shore D80 and a thermal conductivity of not less than 1.0 W / m·K, serving to provide overall structural support and an efficient heat dissipation channel for the coil module. The wireless charging system also includes a magnetic flux limiting and noise reduction control system, which includes a sampling unit, a magnetic flux calculation unit, a control unit, and an inverter drive unit. The sampling unit is used to collect the operating current, real-time charging power, and magnetic core operating temperature of the transmitting coil module in real time. The magnetic flux calculation unit has a built-in magnetic flux density calculation model. It combines the number of coil turns, equivalent length of magnetic circuit, and core temperature of the coil winding to correct the permeability parameter. It then iteratively calculates the current working magnetic flux density value of the core in real time based on the real-time working current and charging power. The control unit is preset with a temperature-compensated magnetic flux limiting threshold. When the real-time magnetic core working magnetic flux density value reaches or exceeds the temperature-compensated magnetic flux limiting threshold, a pulse width modulation control signal is output. The inverter drive unit receives a pulse width modulation control signal and limits the peak value of the excitation current of the transmitting coil module by adjusting the phase shift angle or duty cycle of the drive pulse of the full-bridge inverter circuit, thereby stabilizing the magnetic core working flux density below the flux limiting threshold after temperature compensation.

[0009] Furthermore, the magnetic flux limiting and noise reduction control system also includes a resonance adjustment module, which is electrically connected to the control unit and the LCC-S resonant network respectively. The module is used to dynamically correct the resonance parameters of the LCC-S resonant network by switching the resonant capacitor group or adjusting the adjustable inductor according to the instructions of the control unit, thereby weakening the peak electromagnetic impulse of the primary and secondary sides and further reducing electromagnetic vibration noise.

[0010] Furthermore, the first damping layer is made of silicone, polyurethane elastomer, or butyl rubber, with a single-layer thickness of 0.2mm to 1.0mm. The elastic modulus of the first damping layer is 1MPa to 50MPa. This parameter range is designed based on the following: the lower limit of 1MPa ensures that the material has good flexibility and can deform synchronously with the micron-level magnetostrictive deformation of the magnetic core, achieving viscoelastic strain energy dissipation; the upper limit of 50MPa avoids excessive material hardness and attenuation of internal friction damping capacity, effectively buffering the low-frequency, large-amplitude magnetostrictive vibration of the magnetic core body, achieving source attenuation at the first level of vibration transmission; the second damping layer is made of flexible epoxy resin, foamed epoxy resin, or silicone resin. The second damping layer has an elastic modulus of 0.1MPa to 10MPa and overall flexibility superior to the first damping layer. It can adapt to the electromagnetic jitter characteristics of high-frequency, small-amplitude, and multi-frequency bands of the coil winding, forming a fully encapsulated damping constraint on a single Litz wire, suppressing relative micro-displacement between turns, blocking the vibration transmission path of electromagnetic jitter in the winding, and achieving secondary vibration attenuation. The outer thermally conductive structure layer is made of high thermal conductivity epoxy resin, with a thickness of not less than 2mm after molding. The rigid structure can provide rigid support for the entire coil module, suppressing overall structural resonance. At the same time, its high thermal conductivity can quickly dissipate the working heat of the winding coil and magnetic core, solving the defect of poor heat dissipation in traditional flexible potting structures.

[0011] Furthermore, the potting compound is formed by vacuum layered infusion and segmented stepped heating curing process. The three-layer structure formed by the first damping layer, the second damping layer and the outer thermal conductive structure layer is cross-linked without gaps, which is used to eliminate defects such as internal cavities and delamination, and avoid secondary abnormal noise.

[0012] Furthermore, the sampling unit integrates a temperature sensor to collect the core operating temperature in real time and feed it back to the control unit; the flux calculation unit performs dynamic correction of the permeability parameter based on the core temperature; the control unit performs temperature compensation correction on the reference flux limiting threshold according to the core temperature to obtain the real-time effective flux limiting threshold. The reference flux limiting threshold is 0.35T, which is the inflection point of the nonlinear growth of the core magnetostriction coefficient. When the flux density exceeds this value, the magnetostriction deformation of the core increases sharply, and the noise spikes significantly. The control unit performs dynamic temperature compensation on the reference threshold according to the real-time core temperature to adapt to the full-temperature operating scenario. When the real-time flux density reaches the compensated threshold, the excitation current peak is limited by adjusting the phase shift angle or duty cycle of the full-bridge inverter, locking the core flux density in the low vibration range and suppressing magnetostriction vibration noise from the source.

[0013] Furthermore, the control unit identifies the load condition based on the real-time charging power. Under light load conditions, the magnetic core flux density is low and there is no risk of saturation vibration. It outputs a frequency adjustment signal to increase the switching frequency of the inverter bridge in the full-bridge inverter circuit to above 18kHz, avoiding the 10kHz to 18kHz frequency band that is sensitive to human hearing. Under full load conditions, it locks the resonant operating point of the LCC-S resonant network to maintain the system transmission efficiency, while also achieving low-noise operation in conjunction with magnetic flux limiting.

[0014] Furthermore, the magnetic core is a manganese-zinc ferrite magnetic core that has undergone chamfering and high-temperature stress relief pretreatment.

[0015] Furthermore, a high-power wireless charging control method, applied to the aforementioned active-passive collaborative noise reduction high-power wireless charging system, includes the following steps: S1. The wireless charging system is powered on and initialized. The gradient damping potted coil module enters the passive noise reduction working state. The first damping layer buffers the magnetostrictive vibration of the magnetic core. The second damping layer suppresses the electromagnetic jitter between the coil winding turns. The outer heat-conducting structure layer continuously realizes the structural support and heat dissipation functions. S2. The sampling unit collects the real-time operating current of the transmitting coil module, the real-time charging power of the system, and the operating temperature of the magnetic core. S3. The magnetic flux calculation unit calls the built-in magnetic flux density calculation model, and combines real-time acquired parameters, inherent parameters of coil windings and temperature-corrected permeability to calculate the current working magnetic flux density value of the magnetic core in real time. S4. The control unit determines the load condition based on the real-time charging power and executes the corresponding active noise reduction control strategy: When the system is under light load, the control unit outputs a frequency adjustment signal to raise the inverter bridge switching frequency to above 18kHz through the inverter drive unit, thus avoiding the noise frequency band that is sensitive to the human ear. When the system is under full load and the real-time working magnetic flux density of the magnetic core reaches or exceeds the magnetic flux limiting threshold after temperature compensation, the control unit outputs a pulse width modulation control signal to adjust the drive pulse parameters of the full-bridge inverter circuit, limit the peak value of the excitation current, and stably control the magnetic flux density of the magnetic core below the threshold. S5. The control unit dynamically compensates and corrects the flux limiting threshold based on the real-time temperature of the magnetic core, and drives the resonance adjustment module to correct the resonance parameters of the LCC-S resonant network, thereby achieving coordinated noise reduction control under all operating conditions.

[0016] Furthermore, the light load condition is defined as charging power less than 30% of the system's rated power, and the full load condition is defined as charging power greater than or equal to 30% of the system's rated power; when the system's rated power is 6kW, the light load condition is charging power < 1.8kW, and the full load condition is charging power ≥ 1.8kW.

[0017] Furthermore, the control method executes steps S2-S5 in a fixed cycle of 10ms, namely parameter sampling, magnetic flux calculation, working condition determination, threshold comparison and dynamic adjustment steps.

[0018] The beneficial effects of this invention are: 1. Excellent noise reduction effect with synergistic gain: This invention reduces the noise of a 6kW full-load operating condition to 41dB through an active-passive synergistic noise reduction mechanism, which is 19dB lower than the noise reduction solution without noise reduction, and 3dB and 6dB lower than the single passive structure noise reduction and single active control noise reduction solutions, respectively. It completely solves the technical bottleneck of the limited effect of single noise reduction technology, and the noise performance under full load conditions is better than the traditional solution.

[0019] 2. Balancing heat dissipation and transmission efficiency without performance sacrifice: The high thermal conductivity and rigidity of the outer thermal conductive structure layer ensure the heat dissipation performance of the coil module. The system's full-load temperature rise is only 49.3℃, which is basically the same as the benchmark solution without noise reduction. Active noise reduction does not rely on high-frequency boost frequency modulation. At the same time, magnetic flux limiting keeps the magnetic core away from the saturation region, greatly reducing hysteresis loss and eddy current loss. The overall transmission efficiency of the wireless charging system can reach 93.1%, which is no worse than traditional wireless charging systems, breaking the industry's technical prejudice that noise reduction must sacrifice heat dissipation and efficiency.

[0020] 3. Adaptive to operating conditions and strong operational stability: The wireless charging system can accurately identify light load and full load conditions, adjust the frequency to avoid noise under light load and limit the amplitude to reduce noise under full load. With the help of temperature threshold compensation and dynamic correction of resonance parameters, it can adapt to all temperature and full load working scenarios, greatly improving environmental adaptability and operational reliability.

[0021] 4. High structural reliability and no secondary noise: The three-layer integrated curing potting body has no gaps, no cavities, and no debonding defects, eliminating secondary noise such as structural loosening and cavity resonance after long-term operation, and extending the service life of the equipment. Attached Figure Description

[0022] Figure 1 A schematic diagram of the overall architecture of a high-power wireless charging system with active and passive noise reduction. Figure 2 A partial cross-sectional view of a gradient damping potting coil module; Figure 3 The hardware architecture and signal flow diagram of the flux limiting and silent control system; Figure 4 This is a flowchart illustrating the control method of the present invention; Figure 5 This is a noise comparison curve between the embodiments of the present invention and various comparative examples under different load rates. Detailed Implementation

[0023] like Figures 1 to 4As shown, in this embodiment, the present invention includes a high-power wireless charging system with active and passive coordinated noise reduction and its control method. The high-power wireless charging system with active and passive coordinated noise reduction includes a DC power supply 1, a full-bridge inverter circuit 2, an LCC-S resonant network 3, a transmitting coil module 4, a receiving coil module 5, a rectifier and filter circuit 6, a load module 7, and a magnetic flux limiting and mute control system 8. The transmitting coil module 4 is a gradient damping potted coil module, which includes a magnetic core 41, a coil winding 42, and a potting compound covering the magnetic core 41 and the coil winding 42. The magnetic core 41 is a manganese-zinc ferrite core that has undergone chamfering and high-temperature stress relief pretreatment. Specifically, the magnetic core 41 is a PC40 manganese-zinc ferrite E-type spliced ​​magnetic core with dimensions of 180mm × 120mm × 20mm. m, saturation magnetic flux density 0.51T; the coil winding 42 uses 0.1mm×400 strand Litz wire double-layer parallel winding, with a total of 18 turns; the potting body is provided with a first damping layer 43, a second damping layer 44 and an outer thermal conductive structure layer 45 from the inside out, the three layers are integrally cured and formed to form a gapless cross-linked integrated interface; the first damping layer 43 completely covers the entire outer surface of the magnetic core 41, and is used to absorb the magnetostrictive vibration generated by the high-frequency operation of the magnetic core 41 through elastic viscous deformation buffer; the second damping layer 44 completely fills the inter-turn gap and wire gap of the coil winding 42, and is used to suppress the inter-turn alternating electromagnetic jitter of the coil winding 42 through flexible damping constraint; the outer thermal conductive structure layer 45 is used to provide overall structural support and efficient heat dissipation channel for the coil module; the parameters of each potting material and the preparation process are as follows: The first damping layer 43 is made of high-damping silicone with an elastic modulus of 5 MPa, a loss factor tanδ≥0.3, and a thickness of 0.4 mm; the second damping layer 44 is made of low-viscosity flexible epoxy resin with an elastic modulus of 1 MPa; the outer thermally conductive structural layer 45 is made of high thermal conductivity rigid epoxy potting compound with a Shore hardness of D85, a thermal conductivity of 1.5 W / m·K, and a minimum molding thickness of 2 mm.

[0024] In this embodiment, the fabrication process of the gradient damping potting coil module includes the following steps: Pre-treatment process: All edges and corners of the magnetic core 41 are chamfered with R0.5 to eliminate stress concentration points. Then, it is baked in a high temperature environment of 120℃ for 2 hours to completely remove residual stress from machining and avoid additional vibration caused by the inherent stress of the magnetic core 41.

[0025] Layered potting and curing process: High-damping silicone A / B components are uniformly mixed in a 10:1 ratio. After vacuum degassing, the mixture is uniformly coated onto the entire outer surface of the magnetic core 41 and cured at room temperature to form the first damping layer 43. The main components of the high-damping silicone A are at least one of the following: base silicone raw rubber, filler, damping powder, plasticizer, and reinforcing agent. The high-damping silicone B includes a curing agent and a catalyst. The wound coil winding 42 is attached to the magnetic core 41 for assembly and positioning, placed in a vacuum mold, and injected with flexible epoxy resin under a vacuum environment of -0.095MPa to completely fill the gaps between turns and the wiring. It is pre-cured at 60℃ for 30 minutes to form the second damping layer 44. Finally, high thermal conductivity rigid epoxy resin is vacuum injected, and a segmented stepped temperature curing process is adopted: 70℃ for 1 hour + 90℃ for 2 hours + 110℃ for 1 hour. After natural and slow cooling, it is demolded to form the outer thermally conductive structural layer 45.

[0026] Ultrasonic scanning revealed that the gradient damping potted coil module prepared in this embodiment has a tightly cross-linked three-layer structure with no cavities, no debonding, and no delamination defects. It also possesses multiple properties such as magnetostrictive vibration buffering, winding electromagnetic jitter suppression, efficient heat dissipation, and structural support.

[0027] In this embodiment, the hardware setup and parameter calibration of the magnetic flux limiting and noise reduction control system are as follows: The wireless charging system has a rated power of 6kW and the hardware platform configuration is as follows: DC power supply 1 output range 0~600V / 10kW; full-bridge inverter circuit 2 is integrated into the full-bridge inverter, which uses C3M0040120K type SiC MOSFET power devices; LCC-S resonant network 3 reference resonant frequency 15kHz; transmitting coil module 4 adopts a gradient damped potted coil module, receiving coil module 5 adopts a conventional Litz wire winding structure, and the back-end matching rectifier filter circuit 6 and load module 7.

[0028] In this embodiment, the magnetic flux limiting and silent control system 8 includes a sampling unit 81, a magnetic flux calculation unit 82, a control unit 83, an inverter drive unit 84, and a resonance adjustment module 85. The magnetic flux calculation unit 82 and the control unit 83 are integrated on an STM32H743ARM Cortex-M7 main control chip. The inverter drive unit 84 uses a Si8271 isolated drive chip. The resonance adjustment module 85 has three sets of parallel resonant capacitors and an adjustable inductor built in, which can realize dynamic switching and adjustment of parameters.

[0029] The sampling unit 81 integrates an ACS758LCB-100B Hall current sensor, a high-precision power sampling circuit, and an NTC temperature sensor, and is used to collect the operating current, real-time charging power, and operating temperature of the magnetic core 41 of the transmitting coil module 4 in real time and feed them back to the control unit 83. The magnetic flux calculation unit 82 dynamically corrects the permeability parameter based on the temperature of the magnetic core 41. The magnetic flux calculation unit 82 has a built-in magnetic flux density calculation model, established according to B=μ(T)·N·i / le, where B is the magnetic flux density, le is the equivalent length of the magnetic circuit, μ(T) is the temperature-corrected dynamic permeability calibrated offline, N is the number of turns of the coil winding 42, and i is the instantaneous excitation current of the coil winding 42. The model is corrected in real time using a lookup table method. Combining the number of turns of the coil winding 42, the equivalent length of the magnetic circuit, and the temperature-corrected permeability parameter of the magnetic core 41, the current operating magnetic flux density value of the magnetic core 41 is calculated based on the real-time operating current and charging power. The control unit 83 is preset with a temperature-compensated flux limiting threshold, with a reference threshold of 0.35T. When the real-time operating flux density of the magnetic core 41 reaches or exceeds the temperature-compensated flux limiting threshold, a pulse width modulation (PWM) control signal is output. Specifically, the control unit 83 performs temperature compensation correction on the reference flux limiting threshold of 0.35T based on the temperature of the magnetic core 41, obtaining the actual threshold Blim(T) = 0.35 × [1 - 0.003 × (T - 25℃)]. When the real-time flux is greater than or equal to the actual threshold, a phase shift control signal is output to limit the peak value of the excitation current. The inverter drive unit 84 receives the pulse width modulation control signal and limits the peak value of the excitation current of the transmitting coil module 4 by adjusting the phase shift angle or duty cycle of the drive pulse of the full-bridge inverter circuit 2, thereby stabilizing the working magnetic flux density of the magnetic core 41 below the magnetic flux limiting threshold after temperature compensation. The resonant adjustment module 85 is electrically connected to the control unit 83 and the LCC-S resonant network 3 respectively. It is used to dynamically correct the resonant parameters of the LCC-S resonant network 3 by switching the resonant capacitor group or adjusting the adjustable inductor according to the instructions of the control unit 83, thereby reducing the peak value of the electromagnetic impulse on the primary and secondary sides.

[0030] The control unit 83 identifies the load condition based on the real-time charging power. Under light load conditions (based on the rated 6kW, P<1.8kW), it outputs a frequency adjustment signal to increase the switching frequency of the inverter bridge in the full-bridge inverter circuit 2 to 20kHz (above 18kHz) to avoid the 10kHz~18kHz frequency band that is sensitive to human hearing feedback. Under full load conditions, it locks the resonant operating point of the LCC-S resonant network 3 to maintain the system transmission efficiency.

[0031] In this embodiment, a high-power wireless charging control method is applied to the aforementioned active-passive collaborative noise reduction high-power wireless charging system, comprising the following steps: S1. The wireless charging system is powered on and initialized. The gradient damping potted coil module enters the passive noise reduction working state. The gradient damping potted coil module continuously realizes vibration buffering, jitter suppression and heat dissipation support. Specifically, the first damping layer 43 buffers the magnetostrictive vibration of the magnetic core 41, the second damping layer 44 suppresses the electromagnetic jitter between turns of the coil winding 42, and the outer heat-conducting structure layer 45 continuously realizes the structural support and heat dissipation function. The system uses a fixed control cycle of 10ms to cyclically execute the closed-loop control process S2-S5. S2, Sampling unit 81 collects the real-time operating current of transmitting coil module 4, real-time charging power of system and operating temperature of magnetic core 41; S3. The magnetic flux calculation unit 82 calls the built-in magnetic flux density calculation model, and combines the real-time acquired parameters, the inherent parameters of the coil winding 42 and the temperature-corrected permeability to calculate the current working magnetic flux density value of the magnetic core 41 in real time. S4 and control unit 83 determine the load condition based on the real-time charging power and execute the corresponding active noise reduction control strategy: When the system is under light load, the control unit 83 outputs a frequency adjustment signal, which raises the inverter bridge switching frequency to 20kHz through the inverter drive unit 84 to avoid the noise frequency band that is sensitive to the human ear. When the system is under full load and the real-time working magnetic flux density value of the magnetic core 41 reaches or exceeds the magnetic flux limiting threshold after temperature compensation, the control unit 83 outputs a pulse width modulation control signal to adjust the driving pulse parameters of the full-bridge inverter circuit 2, limit the peak value of the excitation current, and stably control the magnetic flux density of the magnetic core 41 below the threshold, thereby suppressing magnetostrictive vibration from the source. S5 and control unit 83 dynamically compensate for the real-time temperature of magnetic core 41 to correct the magnetic flux limiting threshold, and drive resonance adjustment module 85 to correct the resonance parameters of LCC-S resonant network 3, so as to achieve coordinated noise reduction control under all working conditions.

[0032] In this embodiment, the light load condition is defined as the charging power being less than 30% of the system's rated power, and the full load condition is defined as the charging power being greater than or equal to 30% of the system's rated power. When the system's rated power is 6kW, the light load condition is the charging power being <1.8kW, and the full load condition is the charging power being ≥1.8kW.

[0033] To verify the synergistic noise reduction effect and overall performance of the present invention, such as Figure 5 As shown, four comparison schemes were set up and tested under the rated condition of 6kW full load. The parameters of each group were tested repeatedly three times and the average value was taken. The test results are as follows: Scheme A (Active-Passive Coordination Scheme of the Invention): Operating noise 41dB, maximum core temperature rise 49.3℃, overall transmission efficiency 93.1%; Option B (noise reduction only with passive gradient damping structure, no active control): operating noise 44dB, maximum core temperature rise 49.1℃, overall transmission efficiency 93.2%; Option C (active flux limiting control only, no passive damping structure): operating noise 47dB, maximum core temperature rise 48.5℃, overall transmission efficiency 93.0%; Option D (traditional option without noise reduction benchmark): operating noise 60dB, maximum core temperature rise 48.2℃, overall transmission efficiency 92.8%.

[0034] Experimental data shows that the noise reduction effect of the active-passive synergistic scheme of this invention is significantly better than that of a single noise reduction scheme, exhibiting obvious synergistic gain. Simultaneously, the temperature rise and efficiency indicators are basically the same as those of traditional no-noise-reduction schemes, with no performance degradation, perfectly solving the problem that traditional technologies cannot simultaneously achieve noise reduction, heat dissipation, and efficiency. Combined with noise curves at different load rates, it can be seen that the noise performance of the scheme of this invention is optimal under all light, medium, and full load conditions, demonstrating extremely strong adaptability to all operating conditions.

[0035] The core innovation of this invention lies in the cooperation between the passive noise reduction structure of the gradient damping potting coil module and the active noise reduction strategy of the magnetic flux limiting silent control system, forming a combined active and passive noise reduction mechanism.

[0036] The core synergistic mechanism of this invention is as follows: the passive noise reduction structure is responsible for the multi-level attenuation of the vibration transmission path, the magnetic flux limiting silent control system is responsible for the amplitude suppression of the vibration excitation source, and the active limiting technology reduces the overall vibration strain amplitude of the magnetic core 41 and the coil winding 42, so that the first damping layer 43 and the second damping layer 44 work in the optimal working condition of small strain and high loss factor, which greatly improves the vibration absorption efficiency of passive damping, and finally achieves the super-superimposed synergistic noise reduction effect of "1+1>2", breaking through the noise reduction limit of a single technology.

[0037] Although the embodiments of the present invention are described with reference to actual solutions, they do not constitute a limitation on the meaning of the present invention. Modifications to the embodiments and combinations with other solutions based on this specification will be obvious to those skilled in the art.

Claims

1. A high-power wireless charging system with active and passive coordinated noise reduction, comprising a DC power supply (1), a full-bridge inverter circuit (2), an LCC-S resonant network (3), a transmitting coil module (4), a receiving coil module (5), a rectifier and filter circuit (6), and a load module (7), characterized in that: The transmitting coil module (4) is a gradient damping potted coil module. The gradient damping potted coil module includes a magnetic core (41), a coil winding (42), and a potting body covering the magnetic core (41) and the coil winding (42). The potting body is provided with a first damping layer (43), a second damping layer (44), and an outer thermal conductive structure layer (45) from the inside to the outside. The three-layer structure is integrally cured and formed to form a gapless cross-linked integrated interface. The wireless charging system also includes a magnetic flux limiting and noise reduction control system (8), which includes a sampling unit (81), a magnetic flux calculation unit (82), a control unit (83), and an inverter drive unit (84). The sampling unit (81) is used to collect the operating current, real-time charging power, and operating temperature of the magnetic core (41) of the transmitting coil module (4) in real time. The magnetic flux calculation unit (82) is used to calculate the current working magnetic flux density value of the magnetic core (41) based on the real-time working current and charging power; The control unit (83) is preset with a magnetic flux limiting threshold after temperature compensation. When the working magnetic flux density value of the real-time magnetic core (41) reaches or exceeds the magnetic flux limiting threshold after temperature compensation, it outputs a pulse width modulation control signal. The inverter drive unit (84) receives the pulse width modulation control signal and stably controls the working magnetic flux density of the magnetic core (41) below the magnetic flux limiting threshold after temperature compensation.

2. The high-power wireless charging system with active and passive coordinated noise reduction according to claim 1, characterized in that: The flux limiting and silent control system (8) also includes a resonance adjustment module (85), which is electrically connected to the control unit (83) and the LCC-S resonant network (3) respectively. It is used to dynamically correct the resonance parameters of the LCC-S resonant network (3) by switching the resonant capacitor group or adjusting the adjustable inductor according to the instructions of the control unit (83), thereby weakening the peak value of the electromagnetic shock on the primary and secondary sides. The flux calculation unit (82) has a built-in flux density calculation model. It combines the number of coil turns, equivalent length of magnetic circuit, and temperature correction permeability parameters of the coil winding (42) with the temperature of the core (41) to calculate the current working flux density value of the core (41) according to the real-time working current and charging power. The inverter drive unit (84) receives the pulse width modulation control signal and limits the peak value of the excitation current of the transmitting coil module (4) by adjusting the phase shift angle or duty cycle of the driving pulse of the full-bridge inverter circuit (2), thereby stabilizing the working flux density of the core (41) below the flux limiting threshold after temperature compensation.

3. A high-power wireless charging system with active and passive coordinated noise reduction according to claim 2, characterized in that: The first damping layer (43) is made of silicone, polyurethane elastomer or butyl rubber, with a single layer thickness of 0.2mm to 1.0mm. The elastic modulus of the first damping layer (43) is 1MPa to 50MPa. It is used to absorb the magnetostrictive vibration generated by the high-frequency operation of the magnetic core (41) through elastic viscous deformation buffer. The second damping layer (44) is made of flexible epoxy resin, foamed epoxy resin or silicone gel. The elastic modulus of the second damping layer (44) is 0.1MPa to 10MPa. It is used to suppress the inter-turn alternating electromagnetic jitter of the coil winding (42) through flexible damping constraint. The outer thermal conductive structure layer (45) is made of high thermal conductivity epoxy resin, with a thickness of not less than 2mm after molding. The hardness of the outer thermal conductive structure layer (45) is not less than Shore D80, and the thermal conductivity is not less than 1.0W / m·K.

4. A high-power wireless charging system with active and passive coordinated noise reduction according to claim 2, characterized in that: The potting compound is formed by vacuum layered potting and segmented stepped heating curing process. The three-layer structure interface formed by the first damping layer (43), the second damping layer (44) and the outer thermal conductive structure layer (45) is cross-linked without gaps to eliminate internal cavities and debonding noise defects. The first damping layer (43) completely covers the entire outer surface of the magnetic core (41). The second damping layer (44) completely fills the inter-turn gap and wire gap of the coil winding (42). The outer thermal conductive structure layer (45) is used to provide overall structural support and efficient heat dissipation channel for the coil module.

5. A high-power wireless charging system with active and passive coordinated noise reduction according to claim 2, characterized in that: The sampling unit (81) integrates a temperature sensor to collect the working temperature of the magnetic core (41) in real time and feed it back to the control unit (83); the magnetic flux calculation unit (82) performs dynamic correction of the permeability parameter based on the temperature of the magnetic core (41); the control unit (83) performs temperature compensation correction on the reference magnetic flux limiting threshold according to the temperature of the magnetic core (41) to obtain the real-time effective magnetic flux limiting threshold, and the reference magnetic flux limiting threshold is 0.35T.

6. A high-power wireless charging system with active and passive coordinated noise reduction according to claim 2, characterized in that: The control unit (83) identifies the load condition based on the real-time charging power. Under light load conditions, it outputs a frequency adjustment signal to raise the inverter bridge switching frequency in the full-bridge inverter circuit (2) to above 18kHz, avoiding the sensitive howling frequency band of 10kHz to 18kHz. Under full load conditions, it locks the resonant operating point of the LCC-S resonant network (3) to maintain the system transmission efficiency.

7. A high-power wireless charging system with active and passive coordinated noise reduction according to claim 2, characterized in that: The magnetic core (41) is a manganese-zinc ferrite magnetic core that has undergone chamfering and high-temperature stress relief pretreatment.

8. A high-power wireless charging control method, applied to a high-power wireless charging system with active-passive cooperative noise reduction as described in any one of claims 2-7, characterized in that, Includes the following steps: S1. The wireless charging system is powered on and initialized. The gradient damping potted coil module enters the passive noise reduction working state. The first damping layer (43) buffers the magnetostrictive vibration of the magnetic core (41). The second damping layer (44) suppresses the electromagnetic jitter between turns of the coil winding (42). The outer heat-conducting structure layer (45) continuously realizes the structural support and heat dissipation functions. S2, the sampling unit (81) collects the operating current of the transmitting coil module (4), the real-time charging power of the system, and the operating temperature of the magnetic core (41) in real time; S3, the magnetic flux calculation unit (82) calls the built-in magnetic flux density calculation model, and combines the real-time collected parameters, the inherent parameters of the coil winding (42) and the temperature-corrected permeability to calculate the current working magnetic flux density value of the magnetic core (41) in real time. S4. The control unit (83) determines the load condition based on the real-time charging power and executes the corresponding active noise reduction control strategy: When the system is under light load, the control unit (83) outputs a frequency adjustment signal, which raises the inverter bridge switching frequency to above 18kHz through the inverter drive unit (84) to avoid the noise frequency band that is sensitive to human ears. When the system is under full load and the real-time working magnetic flux density value of the magnetic core (41) reaches or exceeds the magnetic flux limiting threshold after temperature compensation, the control unit (83) outputs a pulse width modulation control signal to adjust the driving pulse parameters of the full-bridge inverter circuit (2), limit the peak value of the excitation current, and stably control the magnetic flux density of the magnetic core (41) below the threshold. S5, the control unit (83) corrects the flux limiting threshold according to the real-time temperature compensation of the magnetic core (41), and drives the resonance adjustment module (85) to correct the resonance parameters of the LCC-S resonance network (3) to achieve coordinated noise reduction control under all working conditions.

9. The high-power wireless charging control method according to claim 8, characterized in that: The light load condition is defined as charging power less than 30% of the system's rated power, and the full load condition is defined as charging power greater than or equal to 30% of the system's rated power. When the system's rated power is 6kW, the light load condition is charging power < 1.8kW, and the full load condition is charging power ≥ 1.8kW.

10. The high-power wireless charging control method according to claim 8, characterized in that: The control method executes steps S2-S5 in a cyclical manner with a fixed period of 10ms.

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