Low-power wireless energy transmission method and device

Abstract

The application discloses a kind of low-power wireless energy transmission method and device, the method includes the following steps: S1: equipment required for test is assembled, including charging device and detection device;S2: after main circuit connection, transmitting coil is connected to power supply, and receiving coil is connected to load;S3: check all lines, and use LCR tester to measure inductance, capacitance and resistance parameters;S4: start power supply, and adjust output voltage, current and frequency parameters of power supply;By connecting the input end of the whole device with power frequency power supply, power frequency alternating current is changed into direct current by AC-DC converter with power factor corrector (PFC), and the power factor of circuit reaches more than 0.99, the direct current is changed into high-frequency alternating current by DC-AC high-frequency converter and sent to transmitting coil, and transmitting coil sends electric energy;The electric energy received by receiving coil is powered for load by high-frequency AC-DC converter, so as to realize wireless charging function.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic field technology, specifically a low-power wireless power transmission method and device. Background Technology

[0002] Wireless power transfer, also known as contactless power transfer, refers to the process of converting electrical energy into other forms of relay energy (such as electromagnetic field energy, laser, microwave, and mechanical waves) through a transmitter, transmitting it over a distance, and then converting the relay energy back into electrical energy through a receiver, thus achieving wireless power transfer.

[0003] Numerous domestic and international institutions, universities, and companies are conducting research on wireless power transfer technology. In my country, wireless charging technology research mainly focuses on electric vehicles and high-speed trains. Theoretically, it has reached or is close to the international advanced level, with some research results leading the world. However, engineering practice is relatively limited, and industrialization lags behind international standards. Currently, electromagnetic induction coupling, magnetic resonance coupling (referred to as "magnetic resonance"), microwave radiation, and photoelectric conversion are the most widely used wireless power transfer methods. A comprehensive comparison of these charging methods aims to achieve a wireless charging technology with relatively low total power transmission, long transmission distance, and high system conversion efficiency.

[0004] Magnetic resonant coupling wireless power transfer is currently the preferred method. According to statistical data, the transmission efficiency of magnetic resonant coupling wireless power transfer can reach over 90% when the distance is below 30cm. However, the transmission efficiency drops sharply when the transmission distance exceeds 30cm. Therefore, the transmission distance and power are not the main research challenges, but rather the improvement of transmission efficiency. To address these issues, a low-power wireless power transfer method and device are proposed. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies and solve the problem of low transmission efficiency in existing energy transmission methods, this invention proposes a low-power wireless energy transmission method and device.

[0006] A low-power wireless power transfer method, comprising the following steps:

[0007] S1: Equipment required for assembly testing, including charging devices and testing devices;

[0008] S2: After the main circuit is connected, connect the transmitting coil to the power supply and the receiving coil to the load;

[0009] S3: Inspect all circuits and use an LCR meter to measure inductance, capacitance, and resistance parameters;

[0010] S4: Turn on the power supply and adjust the power supply's output voltage, current, and frequency parameters;

[0011] S5: Measure the coil power after step S4 adjustment, and measure the working temperature of each part of the system.

[0012] Preferably, in S1, the charging device comprises: PFC rectifier, high-frequency inverter, impedance changer, high-frequency rectifier, transmitting coil, receiving coil, load, power supply, U-shaped magnetic core group and I-shaped magnetic core group.

[0013] The PFC rectifier mainly provides stable DC power supply and improves the rectification power factor.

[0014] The high-frequency inverter mainly converts the DC power supply into high-frequency alternating current.

[0015] The impedance changer mainly performs LC resonance on the alternating current output by the high-frequency inverter to generate hundreds of times of magnetic field energy, and through optimization of the magnetic circuit structure and the coil structure, the energy is efficiently transmitted from the transmitting coil to the receiving coil.

[0016] The high-frequency rectifier mainly changes the high-frequency alternating current received by the receiving coil into DC power supply for the load.

[0017] The combination of U-shaped magnetic core group and I-shaped magnetic core group, together with the shielding structure, can concentrate the magnetic field energy in the transmitting coil and the receiving coil, and can realize the wireless power transmission requirements of total transmission power greater than or equal to 1KW, transmission distance greater than or equal to 1m, and system conversion efficiency greater than or equal to 88%.

[0018] Preferably, in S2, the test device adopts a double-transmitting coil and a single-receiving coil structure, and a single transmitting coil is wound with six turns of 6mm diameter high-frequency wire, and a single receiving coil is made of twelve turns of 6mm diameter high-frequency wire.

[0019] In addition to the U-shaped magnetic group and the I-shaped magnetic core group, magnetic shielding should be appropriately added outside the transmitting coil and the receiving coil to absorb unnecessary leakage magnetic field, and an electric shielding is additionally provided outside to further reduce the influence of coil leakage magnetic field.

[0020] Preferably, in S1, the power supply refers to a 30kw wireless power transmission power supply, the U-shaped magnetic core group is composed of 116 100x25x25mm ferrite magnetic cores, and the I-shaped magnetic core group is composed of 96 100x100x2.5mm magnetic sheets.

[0021] Through the introduction of the U-shaped magnetic core group and the I-shaped magnetic core group, the magnetic field energy of the transmitting coil and the receiving coil can be more effectively concentrated at the two poles, so that the receiving side magnetic core group can obtain the magnetic field generated by the transmitting coil at a distance of 1m.

[0022] Preferably, in the S1, the detection device comprises a signal generator, an oscilloscope, an LCR tester, a voltmeter, an ammeter and an infrared thermal imager.

[0023] Preferably, in the S4, the working frequency of the main circuit is adjusted in the range of 20-150 kHz; and in the S5, the infrared thermal imager is used to measure the working temperature of each part of the system.

[0024] A small power wireless energy transmission device, comprising an electrostatic insulation plate placed on the ground; a plurality of groups of U-shaped magnetic core groups are arranged in the middle of the electrostatic insulation plate; the plurality of groups of U-shaped magnetic core groups are stacked in the middle of the electrostatic insulation plate; two groups of fixed supports are arranged on the surface of the electrostatic insulation plate, and a transmitting coil insulation plate is fixedly connected to the middle of the fixed support; a transmitting coil is wound on the transmitting coil insulation plate; the U-shaped magnetic core group is arranged at the bottom of the fixed support; a receiving coil insulation plate is fixedly connected to the top of the fixed support; an I-shaped magnetic core group is arranged on the receiving coil insulation plate; the end of the transmitting coil is connected with a power supply, and the end of the receiving coil is connected with a load.

[0025] Preferably, an impedance converter and a rectifier are arranged between the receiving coil and the load, the receiving coil is connected to the rectifier, and the impedance converter is connected to the rectifier and the load respectively.

[0026] The present application has the advantages that:

[0027] 1. The present application develops an electromagnetic coil structure and shielding structure with UI-shaped magnetic core, which can concentrate the magnetic field energy in the transmitting coil and the receiving coil. The direct current is converted into high-frequency alternating current through a high-frequency inverter, and through LC resonance, the transmitting coil generates a high-frequency changing strong magnetic field within a certain distance. When the receiving coil is located in the magnetic field, the high-frequency change of the transmitting coil magnetic flux will generate a certain intensity of high-frequency induced electromotive force on the receiving coil side. The electromotive force is enhanced through the receiving side resonance circuit, and then is converted into direct current through the receiving side rectifier device to charge the load. The wireless power transmission technology adopts electromagnetic induction coupling mode for power transmission, eliminates the danger of friction and electric shock, improves the flexibility of system power transmission, and significantly reduces the weight and volume of the power system.

[0028] 2. The input end of the whole device is connected with a power frequency power supply. The power frequency alternating current is converted into direct current through an AC-DC converter with a power factor corrector (PFC), and the power factor of the circuit reaches 0.99 or above. The direct current is converted into high-frequency alternating current through a DC-AC high-frequency converter and is sent to the transmitting coil. The transmitting coil sends electric energy. The electric energy received by the receiving coil is used to supply power to the load through a high-frequency AC-DC converter, so as to realize the wireless charging function. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative labor based on these drawings also belong to the protection scope of the present application.

[0030] Figure 1 The charging technical schematic diagram of an embodiment of the present application;

[0031] Figure 2 The charging device circuit diagram of an embodiment of the present application;

[0032] Figure 3 The magnetic field diagram of a wireless energy transmission device of an embodiment of the present application;

[0033] Figure 4 The magnetic core magnetic field distribution cloud diagram of a wireless energy transmission device of an embodiment of the present application;

[0034] Figure 5 The front view of a wireless energy transmission device of an embodiment of the present application;

[0035] Figure 6 The left view of a wireless energy transmission device of an embodiment of the present application;

[0036] Figure 7 The top view of a wireless energy transmission device of an embodiment of the present application;

[0037] Figure 8 The front view of a transmitting coil of an embodiment of the present application.

[0038] In the figure: 1, electrostatic insulation plate; 2, U-shaped magnetic core group; 3, transmitting coil; 4, transmitting coil insulation plate; 5, fixed support; 6, I-shaped magnetic core group; 7, receiving coil; 8, receiving coil insulation plate; 9, power supply; 12, rectifier; 13, impedance transformer; 14, load. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only represent some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor also belong to the protection scope of the present application.

[0040] Please refer to Figures 1-8 The figure shows a small power wireless energy transmission method, which comprises the following steps:

[0041] S1: Equipment required for assembly testing, including charging devices and testing devices;

[0042] S2: After the main circuit is connected, connect the transmitting coil to the power supply and the receiving coil to the load;

[0043] S3: Inspect all circuits and use an LCR meter to measure inductance, capacitance, and resistance parameters;

[0044] S4: Turn on the power supply and adjust the power supply's output voltage, current, and frequency parameters;

[0045] S5: Measure the coil power after adjustment in step S4, and measure the operating temperature of each part of the system.

[0046] In one embodiment of the present invention, in S1, the charging device includes: a PFC rectifier, a high-frequency inverter, an impedance changer, a high-frequency rectifier, a transmitting coil, a receiving coil, a load, a power supply, a U-shaped magnetic core assembly, and an I-shaped magnetic core assembly.

[0047] The PFC rectifier mainly provides a stable DC power supply and improves the rectified power factor.

[0048] High-frequency inverters primarily convert DC power into high-frequency AC current.

[0049] The impedance transformer mainly uses LC resonance to generate hundreds of times the magnetic field energy from the AC power output of the high-frequency inverter. By optimizing the magnetic circuit structure and coil structure, the energy is efficiently transferred from the transmitting coil to the receiving coil.

[0050] High-frequency rectifiers primarily convert the high-frequency AC power received by the receiving coil into DC power for use by the load.

[0051] Specifically, the key to this energy transfer method lies in the combination of U-shaped magnetic core groups and I-shaped magnetic core groups, along with the shielding structure, which can concentrate the magnetic field energy in the transmitting coil and the receiving coil. This enables wireless power transmission that simultaneously meets the requirements of a total transmission power of ≥1KW, a transmission distance of ≥1m, and a system conversion efficiency of ≥88%. It also solves the problem that the magnetic field energy of existing electromagnetic coils is relatively dispersed and has a significant electromagnetic impact on surrounding devices.

[0052] In addition, such as Figure 1 As shown, the electromagnetic field under the simulated resonant operation of the transmitting and receiving sides is different from the electromagnetic field under the open-circuit and short-circuit conditions of the receiving side, which is the actual operating condition of the load.

[0053] As an embodiment of the present application, in S2, the test device adopts a structure of double transmitting coils and single receiving coil, and the single transmitting coil is made of six turns of high-frequency wire with a diameter of 6 mm, and the single receiving coil is made of twelve turns of high-frequency wire with a diameter of 6 mm.

[0054] Specifically, in addition to adopting the U-shaped magnetic group and the I-shaped magnetic core group, magnetic shielding should be appropriately added outside the transmitting coil and the receiving coil to absorb unnecessary leakage magnetic flux, and electric shielding should be additionally added outside to further reduce the influence of coil leakage magnetic flux, and anti-magnetic shielding should be arranged at appropriate positions of the coil to prevent part of the leakage magnetic flux from passing through.

[0055] In addition, as shown in the figure, the shape, the number of turns, the position of the two transmitting coils and the position of the transmitting magnetic core are optimized, and the width, the length, the number of turns and other parameters of the receiving coil are optimized to cooperate with the magnetic circuit optimization to maximize the wireless power transmission. Figure 3

[0056] As an embodiment of the present application, in S1, the power source refers to a 30kw wireless power transmission power source, the U-shaped magnetic core group is made of 116 pieces of 100x25x25mm ferrite magnetic core, and the I-shaped magnetic core group is made of 96 pieces of 100x100x2.5mm magnetic sheet.

[0057] Specifically, through the introduction of the U-shaped magnetic core group and the I-shaped magnetic core group, the magnetic field energy of the transmitting coil and the receiving coil can be more effectively concentrated at the two poles, so that the receiving side magnetic core group can remotely obtain the magnetic field generated by the transmitting coil at a distance of 1m.

[0058] As shown in the figure, the magnetic field distribution in the transmitting magnetic core and the receiving magnetic core can be obtained, so that the resonance frequency can be further optimized, and the magnetic flux density of the transmitting magnetic core and the receiving magnetic core can be reasonably designed to realize the optimal matching of the amount of magnetic core and the loss of magnetic core. Figure 4

[0059] As an embodiment of the present application, in S1, the detection device includes a signal generator, an oscilloscope, an LCR tester, a voltmeter, an ammeter and an infrared thermal imager.

[0060] As an embodiment of the present application, in S4, the working frequency of the main circuit is adjusted in the range of 20-150kHz; and in S5, the infrared thermal imager is used to measure the working temperature of each part of the system.

[0061] Specifically, when the system resonance frequency is 82.5kHz and the working frequency is set in the range of 20-150kHz, the transmission power of the receiving coil reaches 100W-7.7kW.

[0062] ​​A kind of low-power wireless energy transfer device, including placing on the ground electrostatic insulation board 1;The middle part of the electrostatic insulation board 1 is provided with several groups of U-shaped magnetic core group 2;Several groups of the U-shaped magnetic core group 2 is stacked in the middle part of electrostatic insulation board 1;Two groups of fixed support 5 are provided on the surface of the electrostatic insulation board 1, and the middle part of the fixed support 5 is fixedly connected with transmitting coil insulation board 4;Transmitting coil 3 is wound on the transmitting coil insulation board 4;The U-shaped magnetic core group 2 is arranged at the bottom of fixed support 5;The top of the fixed support 5 is fixedly connected with receiving coil insulation board 8;I-shaped magnetic core group 6 is provided on the receiving coil insulation board 8;The end of the transmitting coil 3 is communicated with power supply 9, and the end of the receiving coil 7 is communicated with load 14.

[0063] Specifically, wherein the electrostatic insulation board 1 is the appearance size 2100 × 1000 × 2 millimeter rectangular insulating rubber board, fixed support 5 is made of 50 × 50 millimeter laminated wood, each part is connected using mortise and tenon structure, and the position of transmitting coil 3 needs to be 600 millimeters away from the ground height, and the distance between transmitting coil 3 and receiving coil 7 needs to be greater than or equal to 1 m;

[0064] Specifically, power factor corrector and DC-AC inverter are further provided between power supply 9 and transmitting coil 3.

[0065] As an embodiment of the application, impedance transformer 13 and rectifier 12 are provided between receiving coil 7 and load 14, and receiving coil 7 is communicated on rectifier 12, and impedance transformer 13 is respectively communicated with rectifier 12 and load 14.

[0066] Working principle:

[0067] After the completion of main circuit connection, transmitting coil 3 is connected to power supply 9, receiving coil 7 is connected to load 14, all lines are checked, LCR tester is used to measure inductance, capacitance and resistance parameters in the system, power supply 9 is started, output voltage, current and frequency parameters of power supply 9 are adjusted, power of receiving coil 7 is measured, infrared thermal imager is used to measure working temperature of each part of the system, when working frequency is set in the range of 20-150 kHz, transmission power of receiving coil 7 reaches 100 W-7.7 kW;

[0068] 3. By developing an electromagnetic coil structure with a UI type magnetic core and a shielding structure, the magnetic field energy can be concentrated in the transmitting coil 3 and the receiving coil 7, the direct current is converted into high-frequency alternating current by the high-frequency inverter, and through LC resonance, the transmitting coil 3 generates a high-frequency changing strong magnetic field within a certain distance around it, and when the receiving coil 7 is located in this magnetic field, the high-frequency change of the magnetic flux of the transmitting coil 3 will generate a certain intensity of high-frequency induced electromotive force on the side of the receiving coil 7, this electromotive force is enhanced through the receiving side resonance circuit, and then through the receiving side rectifier device, it is converted into direct current to charge the load 14; further by connecting the input end of the entire device with the power frequency power supply 9, the power frequency alternating current is converted into direct current through the AC-DC converter with power factor corrector (PFC) and makes the power factor of the circuit reach above 0.99, the direct current is converted into high-frequency alternating current through the DC-AC high-frequency converter and sent to the transmitting coil 3, and the transmitting coil 3 transmits electric energy; the electric energy received by the receiving coil 7 is supplied to the load 14 through the high-frequency AC-DC converter, thereby realizing the wireless charging function; the wireless power transmission technology adopts electromagnetic induction coupling mode for power transmission, eliminates the danger of friction and electric shock, improves the flexibility of system power transmission, and significantly reduces the weight and volume of the power system.

[0069] In the description of the present specification, the description referring to the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0070] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A method of low power wireless power transfer, characterized by: The method comprises the following steps: S1: Assemble the test required equipment, including charging device and detection device; S2: After the main circuit is connected, the transmitting coil is connected to the power supply, and the receiving coil is connected to the load; S3: Check all lines, and measure the inductance, capacitance and resistance parameters using the LCR tester; S4: Start the power supply, and adjust the output voltage, current and frequency parameters of the power supply; S5: Measure the coil power after the adjustment in step S4, and measure the working temperature of each part of the system; In S1, the charging device comprises a PFC rectifier, a high-frequency inverter, an impedance changer, a high-frequency rectifier, a transmitting coil, a receiving coil, a load, a power supply, a U-shaped magnetic core group and an I-shaped magnetic core group; The PFC rectifier mainly provides a stable DC power supply and improves the rectification power factor; The high-frequency inverter mainly converts the DC power supply into a high-frequency AC current; The impedance changer mainly performs LC resonance on the AC power supply output by the high-frequency inverter to generate a magnetic field energy of hundreds of times, and through optimization of the magnetic circuit structure and the coil structure, the energy is efficiently transmitted from the transmitting coil to the receiving coil; The high-frequency rectifier mainly changes the high-frequency AC power supply received by the receiving coil into a DC power supply for use by the load.

2. A method of low power wireless energy transfer as claimed in claim 1, wherein: In S2, the test device adopts a double-transmitting coil and single-receiving coil structure, and a single transmitting coil is wound with six turns of a 6mm-diameter high-frequency wire, and a single receiving coil is made by winding twelve turns of a 6mm-diameter high-frequency wire.

3. A method of low power wireless energy transfer according to claim 2, wherein: In S1, the power supply refers to a 30kw wireless energy transmission power supply, the U-shaped magnetic core group is stacked by 116 100*25*25mm ferrite magnetic cores, and the I-shaped magnetic core group is bonded by 96 100*100*2.5mm magnetic sheets.

4. A method of low power wireless energy transfer according to claim 3, wherein: In S1, the detection device comprises a signal generator, an oscilloscope, an LCR tester, a voltmeter, an ammeter and an infrared thermal imager.

5. A method of low power wireless energy transfer according to claim 4, wherein: In S4, the working frequency of the main circuit is adjusted within the range of 20-150kHz; and in S5, the infrared thermal imager is used to measure the working temperature of each part of the system.

6. A low power wireless power transfer device, characterized by: The static electricity insulation board (1) is placed on the ground; a plurality of U-shaped magnetic core groups (2) are arranged in the middle of the static electricity insulation board (1); the plurality of U-shaped magnetic core groups (2) are stacked in the middle of the static electricity insulation board (1); two fixed supports (5) are arranged on the surface of the static electricity insulation board (1), and a transmitting coil insulation board (4) is fixedly connected to the middle of each fixed support (5); a transmitting coil (3) is wound on the transmitting coil insulation board (4); the U-shaped magnetic core group (2) is arranged at the bottom of the fixed support (5); a receiving coil insulation board (8) is fixedly connected to the top of the fixed support (5); an I-shaped magnetic core group (6) is arranged on the receiving coil insulation board (8); a power supply (9) is connected to the end of the transmitting coil (3), and a load (14) is connected to the end of the receiving coil (7). The impedance transformer (13) and the rectifier (12) are arranged between the receiving coil (7) and the load (14), and the receiving coil (7) is connected to the rectifier (12), and the impedance transformer (13) is connected to the rectifier (12) and the load (14) respectively.

Images