CN114825661B - Optimal design method for wireless power transmission system of electric automobile - Google Patents
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- 208000017096 leukoencephalopathy with calcifications and cysts Diseases 0.000 claims description 37
- 238000007600 charging Methods 0.000 claims description 21
- 239000003990 capacitor Substances 0.000 claims description 14
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 12
- 229910052744 lithium Inorganic materials 0.000 claims description 12
- 238000010280 constant potential charging Methods 0.000 claims description 6
- 238000010277 constant-current charging Methods 0.000 claims description 4
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- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
- H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling
- H02J50/12—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling of the resonant type
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- B60L53/00—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
- B60L53/10—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles characterised by the energy transfer between the charging station and the vehicle
- B60L53/14—Conductive energy transfer
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02T90/10—Technologies relating to charging of electric vehicles
- Y02T90/16—Information or communication technologies improving the operation of electric vehicles
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
- Electric Propulsion And Braking For Vehicles (AREA)
Abstract
The invention relates to an optimal design method of a wireless electric energy transmission system of an electric automobile. The invention adopts a magnetic coupling mode to measure the current of the primary coil, and compared with a power resistor sampling mode, the magnetic coupling mode realizes the electrical isolation of the measuring circuit and the main power circuit. The self inductance of the small coil is negligible compared with the secondary coil, and the influence on the efficiency of wireless power transmission is small. A de-feedback scheme is provided for all wireless transmission applications. The scheme does not need to add a new wireless communication system to the system, and reduces the complexity of the system. The feedback system required in the wireless power transmission process of the electric automobile based on LCC topology can be effectively removed, the leakage magnetic field generated in the wireless power transmission process is utilized, the originally lost leakage magnetic field is used as the basis for representing the current of the primary coil, and the efficiency of the system is improved.
Description
Technical Field
The invention belongs to the technical field of power electronics, and particularly relates to an optimal design method of a wireless power transmission system of an electric automobile.
Background
At present, environmental problems and energy crisis are becoming more severe, and new energy automobiles represented by electric automobiles are gradually replacing traditional automobiles with the advantages of silence, cleanness, energy regeneration and the like. The charging modes of the electric automobile can be divided into a wired charging mode and a wireless charging mode. Under the condition of high-power transmission of electric energy, the wireless charging mode does not need a heavy and expensive charging plug, and a user does not need to directly process high-voltage electricity, so that the cost of the system is reduced, and the charging safety is improved. Whether wireless charging or wired charging, the charging process of the lithium battery needs to be precisely controlled to improve the charging speed and the service life of the lithium battery, and the method is characterized in that the lithium battery is charged in steps with constant current and constant voltage, and in this aspect, the wireless charging still has defects compared with the wired charging. In many existing wireless charging systems, the charging control is performed by adopting DC-DC, but the number of cascade systems is inevitably increased, and the efficiency of the system is reduced.
In recent years, students propose to utilize two different electric characteristics of resonance points of double-sided LCC to realize constant-current and constant-voltage charging systems, and the systems better solve the problem of constant-current and constant-voltage charging control of wireless charging, but have larger defects: these systems require that the secondary coil end continuously send charge status information to the primary coil end to prompt the control circuit to change the transmission frequency, which results in the need to design a new wireless communication protocol between the electric vehicle and the charging system, which would greatly limit the application of wireless charging.
Disclosure of Invention
The invention aims to provide an optimal design method of a wireless electric energy transmission system of an electric automobile.
The method specifically comprises the following steps:
step one, determining the size, the size and the number of turns of a primary coil and a secondary coil for wireless power transmission.
And step two, determining the length of the air gap between the primary coil and the secondary coil according to the size and the number of turns information of the coils.
And step three, under the condition of given coil size and air gap, measuring the inductance L 1、L2 of the two coils and the mutual inductance M between the two coils.
And fourthly, selecting the value of L 1p、L1s、C1p、C2p、C1s、C2s of LCC topology within the range of 0-200 kHz. Wherein L 1p、L1s is a series inductance of the primary and secondary LCC topology, C 1p、C1s is a series capacitance of the primary and secondary LCC topology, and C 2p、C2s is a parallel capacitance of the primary and secondary LCC topology. The LCC topology constant current output angular frequency point omega CC meets the following conditions:
wherein the LCC topology parameters of the primary side and the secondary side are consistent:
for a constant voltage output angular frequency ω CV, the circuit parameters should satisfy:
Wherein/>
Through the calculation, a rough reference is provided when determining the values of components of the LCC topology, and the selected LCC topology is ensured to enable two frequency points of a circuit to fall within a 20-200KHz range.
Step five, determining the output angular frequency of constant current and constant voltage. The primary LCC topology was excited with a square wave inverter, with a 70 ohm purely resistive load connected to the secondary winding. One channel of the oscilloscope is connected to two ends of the load to observe waveforms at two ends of the load. The frequency of the inverter is increased from 0, and when the voltage across the load is seen to be greater than 1dB compared to the supply voltage gain, the frequency magnitude is recorded. The frequency of the inverter continues to be increased until a second frequency point occurs. The first angular frequency point is omega CC, which is a constant-current charging angular frequency point, and the second angular frequency point is omega CV, which is a constant-voltage charging angular frequency point. And if the two obtained frequency points are not in the frequency range of 20-200kHz, changing each parameter value of LCC topology in the fourth step, and repeating the fifth step until the size of omega CC、ωCV meets the design requirement.
The impedance of the secondary coil equivalent alongside the primary coil is expressed as:
Wherein R AC is the load AC equivalent impedance. As the charging voltage increases, the equivalent load of the lithium battery increases. From the impedance representation it can be derived: the impedance of the receiving end equivalent beside the primary coil will also increase, which will inevitably lead to a decrease in the current of the primary coil, thus reducing the excited magnetic field, which will be an important basis for feedback-free wireless power transmission.
And step six, designing and installing a small coil receiving circuit. A small coil is mounted beside the primary transmitting coil, and a capacitor is connected in parallel to the coil, so that the resonance frequency of the coil and the capacitor is at omega CC. Meanwhile, a change-over switch is added for realizing the change-over of the resonance frequency of the small-coil LC circuit, so that the small-coil LC circuit can pick up a signal with the frequency omega CV. And then, rectifying, filtering and calculating the voltage output by the LC resonance circuit and providing the voltage to a next-stage circuit. The designed coil is fixed on the same plane of the primary coil, and the fixed position is required to meet the condition that the coupling coefficient between the primary coil and the small coil is between 0.05 and 0.08, and the specific size is determined according to the power supply voltage in application.
And step seven, setting a frequency switching threshold voltage. The magnitude of the current excited in the small coil is only dependent on the magnitude of the voltage across the primary coil, which will increase with increasing load. The magnitude of the current excited in the small coil can be used as a basis for characterizing the magnitude of the primary voltage, and since the magnitude of the primary voltage is related to the load resistance, the magnitude of the voltage across the primary coil can be used to characterize the magnitude of the secondary load. In the practical application process, the threshold value of the voltage of the jump edge generation time is set according to the electrical characteristics of the lithium battery.
And step eight, designing a singlechip control system. The singlechip system is used for receiving the jump edge output by the small coil circuit designed in the step seven and changing the transmitting frequency according to the jump edge.
The invention has the beneficial effects that:
1. The feedback system required in the wireless power transmission process of the electric automobile based on LCC topology can be effectively removed, and a feedback removing scheme is provided for all wireless transmission applications. The scheme does not need to add a new wireless communication system to the system, and reduces the complexity of the system.
2. The system utilizes the leakage magnetic field generated in the wireless power transmission process, takes the originally lost leakage magnetic field as the basis for representing the current of the primary coil, and increases the efficiency of the system.
3. The system adopts a magnetic coupling mode to measure the current of the primary coil, and compared with a power resistor sampling mode, the magnetic coupling mode realizes the electrical isolation between a measuring circuit and a main power circuit. The self inductance of the small coil is negligible compared with the secondary coil, and the influence on the efficiency of wireless power transmission is small.
Drawings
FIG. 1 is a simplified circuit diagram of a two-sided LCC topology wireless power transfer system;
FIG. 2 is a simplified circuit diagram of a dual sided LCC topology feedback system;
FIG. 3 is a waveform of the output voltage of the LCC topology 50KHz secondary winding;
FIG. 4 is a waveform of the LCC topology 20KHz secondary winding output voltage;
FIG. 5 is a20 KHz output voltage waveform for a small coil;
fig. 6 is a circuit diagram of a small coil output voltage processing circuit.
Detailed Description
The present system is further described below with reference to the accompanying drawings.
As shown in fig. 1, an electric vehicle wireless power transmission system includes a full-bridge inverter circuit, primary and secondary LCC topology circuits, a transmitting coil and receiving coil, a rectifying circuit, a filter circuit, and a load. The system adopts a high-power MOSFET full-bridge inverter circuit, wherein the selected MOSFET is an FDA50N50 MOSFET manufactured by XXX company, is an N-channel MOSFET, and has a VDSS of 500V and an ID of 48A. The system adopts STM32F103C8T6 singlechip of the semiconductor company as a main controller. The system is powered by a high-power direct-current power supply, and the power supply voltage is set to be 200V. The system adopts a GDT mode to drive the MOSFET, thereby realizing the electrical isolation between the driving circuit and the power supply. The topology capacitor adopts a polyethylene capacitor, and the withstand voltage value is 600V. The topological inductance is a spiral coil, and adopts an air magnetic core, so that the magnetic saturation condition is not easy to be achieved under the condition of high current. The transmitting coil is wound by adopting 1mm and 20 Litz wires, the coil is a circular plane spiral coil, the diameter of the coil is 50CM, and the number of turns of the coil is 30. The rectifier bridge is a type GBJ3510 rectifier bridge manufactured by XXX corporation, and can handle a maximum current of 35A. The filter capacitor adopts a 22uF polymer capacitor, and the withstand voltage value is 500V. The load adopts a 100W 70 ohm load resistor.
As shown in fig. 2, the invention adds a coupling inductance to the primary coil and the secondary coil for realizing the feedback-removing function; the coupling coefficient between the coupling inductance and the secondary coil is negligible, and for simplicity of analysis, the system assumes a coupling coefficient of 0 between the small coil and the secondary coil. In the system, the small coil adopts a planar spiral coil structure, the number of turns of the coil is 6 turns, the diameter of the coil is 6CM, and ferrite is arranged at the bottom of the coil to be used as a shield. And a capacitor connected in parallel with the small coil, wherein a relay is used as a resonant capacitor change-over switch. The LC parallel resonant tank can be switched between two frequency points to handle different transmission frequencies.
An optimal design method for a wireless electric energy transmission system of an electric automobile comprises the following specific steps:
step one, determining the size, the size and the number of turns of a primary coil and a secondary coil for wireless power transmission. When the information such as the charging power, the height of the chassis from the ground and the like of the automobile is determined, the information such as the current flowing through the coil, the selected power supply voltage and the like can be roughly determined, and thus the information such as the wire diameter of the coil, the coil diameter and the like can be determined. The wireless power transmission frequency of the electric automobile is in the range of 20-200KHz, the transmission power is more than 1KW, and the transmission power is controlled according to the conductor skin depth:
where ρ is the resistivity, ω is the operating angular frequency, μ is the permeability. The skin depth of copper is about 0.209mm at 20 ℃ and 100KHz working frequency, so when Litz wires are selected, litz wires with small wire diameters smaller than 0.2mm are selected, which is beneficial to reducing the internal resistance of the coil and improving the coil efficiency. Under the operation of transmission power of more than 1KW, the current in the coil is more than 5A, and a litz wire with the diameter of more than 1mm is selected to wind the coil.
And step two, determining the length of the air gap between the primary coil and the secondary coil according to the size and the number of turns information of the coils. The length of the air gap between the primary coil and the secondary coil is determined according to the height of the chassis of the application vehicle, the size of the coil and the size of transmission power.
And step three, under the condition of given coil size and air gap, measuring the inductance L 1、L2 of the two coils and the mutual inductance M between the two coils. And connecting the SMA heads to the coils installed in the steps, and measuring the mutual inductance between the two coils and the respective inductance L 1、L2 by using a vector network analyzer.
And step four, selecting the value of L 1p、L1s、C1p、C2p、C1s、C2s of LCC topology within the range of 0-200kHz, wherein L 1p、L1s is respectively a serial inductor of the primary and secondary side LCC topology, C 1p、C1s is respectively a serial capacitor of the primary and secondary side LCC topology, and C 2p、C2s is respectively a parallel capacitor of the primary and secondary side LCC topology. The values of the primary and secondary LCC topologies should be consistent, i.e., satisfy:
The angular frequency magnitude ω CC of the LCC topology constant current output is expressed as:
the inductance of LCC topology is selected as hollow spiral inductance, and the magnitude of inductance Wherein d is the diameter of the spiral coil, and n is the number of turns of the spiral coil.
The air core inductor is difficult to generate magnetic saturation phenomenon due to overlarge current. In this example, a spiral coil was wound on a paper tube having a diameter of 10CM, the length of the coil was 11mm, the number of turns was 12 turns, and the calculated inductance value was 49.7uH. The topological capacitance selected by the system is C 1p＝C1s＝47nF,C2p＝C2s = 100nF. All components and coils are connected through litz wires.
For a constant voltage output angular frequency ω CV, the circuit parameters should satisfy:
Wherein/>
Through the calculation, a rough reference is provided when determining the values of components of the LCC topology, and the selected LCC topology is ensured to enable two frequency points of a circuit to fall within a 20-200KHz range. Z 1、Z2、Z3、ZM has no specific meaning and is used only in intermediate amounts.
Step five, determining the output angular frequency of constant current and constant voltage. The primary and secondary coils are fixed according to the length of the air gap, and the circle centers of the primary and secondary coils are ensured to be mutually overlapped. The secondary LCC topology output is connected with a 70 ohm resistance load. The primary coil circuit is excited by the square wave inverter, the emission frequency of the inverter is changed, the output voltage is measured by the oscillograph at two ends of the load, and when the gain of the output voltage relative to the power supply voltage is greater than 1dB, the frequency point at the moment can be determined as a resonance frequency point. In the embodiment, the positions of the two resonance frequency points are 20KHz and 50KHz, wherein 20KHz is constant-current output angular frequency, and 50KHz is constant-voltage output angular frequency. The resulting output waveforms are shown in fig. 3 and 4.
And step six, designing and installing a small coil receiving circuit. And determining the installation position of the small coil so that the coupling coefficient of the small coil and the original coil is in the range of 0.05-0.08, and selecting the coupling coefficient in the range according to the application scene. The coupling coefficient of this embodiment is 0.06. When the power supply voltage is 200V and the load is 70 ohms, the voltage in the small coil is about 12V. The excitation voltage of about 12V is still too high compared with the single chip microcomputer system, and the output voltage of the small coil needs to be processed. The small coil output voltage processing circuit diagram is shown in fig. 6. In order to enable the coil to receive electromagnetic fields excited by two resonance frequency points at the same time, the capacitance parallel to the coil must be changed to change the resonance frequency value of the LC resonance circuit. The embodiment adopts a double-channel relay as a selection switch for selecting the parallel resonant circuit. At the 50KHz resonance frequency point, the capacitance parallel to the coil is 367nF, and at the 20KHz resonance frequency point, the capacitance parallel to the coil is 430nF. The small coil output voltage waveform is shown in fig. 5. And filtering and rectifying the output voltage of the resonant circuit to obtain direct-current voltage, wherein the rectifying diode uses IN4007, and the filtering capacitor uses 220nF capacitor. The rectified and filtered voltage is divided and then input to the same-direction input end of the LM393 voltage comparator, and the reverse input end of the comparator is the voltage of the potentiometer voltage divider.
And step seven, setting a frequency switching threshold voltage. By varying the voltage value at the inverting input, a frequency-switched primary voltage threshold is set.
Measuring the mutual inductance coefficient M PS between the primary coil and the small coil, deducing the current excited in the small coil in the parallel resonant circuit of the small coil
Similarly, in the constant voltage charging stage, the capacitance parallel to the small coil is changed, so that the resonance frequency of the LC circuit is located at ω CV. The magnitude of the parallel resonant tank open circuit voltage is: Where Iin is the input current, Z R is the equivalent impedance of the secondary coil beside the primary coil, and M is the mutual inductance between the primary coil and the small coil. Both Z R and Iin show a linear increasing trend with increasing load, and the magnitude of the current excited in the small coil will increase linearly with increasing load resistance with unchanged circuit parameters.
Taking a high-power lithium battery as an example, when the equivalent load of the lithium battery is increased from 30Ω to 90Ω, the voltage at the two ends of the primary coil will be increased by 3 times, the voltage excited by the small coil will be reduced, and when the voltage drops to a set threshold voltage, the output level of the comparator will be changed, so as to remind the inverter to change the emission frequency.
And step eight, designing a singlechip control system. When the voltage excited by the small coil is rectified, filtered and divided and is larger than the voltage of the reverse input end, the output voltage of the comparator is changed from high to low. In the charging process, the lithium battery is charged in a constant-current mode, and constant-voltage charging is performed after the voltage at two ends of the lithium battery reaches a certain value, so that the voltage of the lithium battery is higher and the external equivalent resistance is higher in the process. The PWM output frequency should be set to 20KHz in the microcontroller, and then switched to 50KHz when the switching time arrives. The microcontroller may use the form of an external interrupt, capture the falling edge of the comparator, change the coil transmit frequency within the interrupt service function, and switch the select channel of the relay, change the size of the capacitance in parallel with the small coil, and change the resonant frequency of the LC loop.
Claims (1)
1. An optimal design method of a wireless electric energy transmission system of an electric automobile is characterized by comprising the following steps of:
the method specifically comprises the following steps:
step one, determining the size, the size and the number of turns of a primary coil and a secondary coil for wireless power transmission;
Step two, determining the length of an air gap between the primary coil and the secondary coil according to the size and the number of turns information of the coils;
Measuring the inductance L 1、L2 of the two coils and the mutual inductance M between the two coils under the condition of given coil size and air gap;
Step four, selecting the value of L 1p、L1s、C1p、C2p、C1s、C2s of LCC topology within the range of 0-200 kHz; wherein L 1p、L1s is a series inductance of the primary and secondary side LCC topology, C 1p、C1s is a series capacitance of the primary and secondary side LCC topology, and C 2p、C2s is a parallel capacitance of the primary and secondary side LCC topology; the LCC topology constant current output angular frequency point omega CC meets the following conditions:
wherein the LCC topology parameters of the primary side and the secondary side are consistent:
for a constant voltage output angular frequency ω CV, the circuit parameters should satisfy:
Wherein/>
Through the calculation, a rough reference is provided when the values of components of the LCC topology are determined, and the selected LCC topology is ensured to enable two frequency points of a circuit to fall within a 20-200KHz interval;
Step five, determining the output angular frequency of constant current and constant voltage; exciting the primary LCC topology by using a square wave inverter, and connecting a 70 ohm pure resistive load to the secondary coil; connecting one channel of the oscilloscope to two ends of a load to observe waveforms at two ends of the load; increasing the frequency of the inverter from 0, and recording the frequency when the voltage at two ends of the load is larger than 1dB compared with the power supply voltage gain; continuing to increase the frequency of the inverter until a second frequency point appears; the first angular frequency point is omega CC, which is a constant-current charging angular frequency point, and the second angular frequency point is omega CV, which is a constant-voltage charging angular frequency point; if the two obtained frequency points are not in the frequency range of 20-200kHz, changing each parameter value of LCC topology in the fourth step, and repeating the fifth step until the size of omega CC、ωCV meets the design requirement;
the impedance of the secondary coil equivalent alongside the primary coil is expressed as:
Wherein R AC is load AC equivalent impedance; as the charging voltage increases, the equivalent load of the lithium battery increases; from the impedance representation it can be derived: the impedance of the receiving end equivalent beside the primary coil will also increase, which necessarily results in a decrease in the current of the primary coil, thereby reducing the excited magnetic field;
Step six, designing and installing a small coil receiving circuit; a small coil is arranged beside the primary transmitting coil, and a capacitor is connected in parallel to the coil, so that the resonance frequency of the coil and the capacitor is positioned at omega CC; meanwhile, a change-over switch is added for realizing the switching of the resonance frequency of the small-coil LC circuit, so that the small-coil LC circuit can pick up a signal with the frequency of omega CV; then, rectifying, filtering and calculating the voltage output by the LC resonance circuit and providing the voltage to a next-stage circuit; fixing the designed coil on the same plane of the primary coil, wherein the fixed position is required to meet the condition that the coupling coefficient between the primary coil and the small coil is between 0.05 and 0.08;
Step seven, setting a frequency switching threshold voltage; the magnitude of the current excited in the small coil is only dependent on the magnitude of the voltage across the primary coil, which will increase with increasing load; the magnitude of the current excited in the small coil can be used as a basis for representing the magnitude of the primary voltage, and the magnitude of the voltage across the primary coil can represent the magnitude of the secondary load because the magnitude of the primary voltage is related to the load resistance; setting the threshold value of the voltage of the jump edge generation time according to the electrical characteristics of the lithium battery;
Step eight, designing a singlechip control system; the singlechip system is used for receiving the jump edge output by the small coil circuit designed in the step seven and changing the transmitting frequency according to the jump edge.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20170059391A (en) * | 2015-11-20 | 2017-05-30 | 숭실대학교산학협력단 | Double sided resonant converter for wireless charger and method for implementing thereof |
| CN107425610A (en) * | 2017-05-10 | 2017-12-01 | 北京交通大学长三角研究院 | Radio energy transmission system and control method based on energy resource system load compensation in parallel |
| CN109474081A (en) * | 2018-09-06 | 2019-03-15 | 西安理工大学 | Based on radio energy transmission system constant current-constant voltage output characteristic charging method |
| CN110429720A (en) * | 2019-08-20 | 2019-11-08 | 南京航空航天大学 | A kind of induction type radio energy transmission system for realizing constant current constant voltage output switching |
| CN110855020A (en) * | 2019-11-11 | 2020-02-28 | 暨南大学 | Constant-voltage wireless charging system based on LCCL-LC compensation and parameter design method |
| CN112202251A (en) * | 2020-12-04 | 2021-01-08 | 南京航空航天大学 | Compensation parameter design method of wireless power transmission circuit capable of self-adapting and full tuning |
-
2021
- 2021-05-27 CN CN202110586119.1A patent/CN113364141A/en active Pending
- 2021-11-15 CN CN202111347028.9A patent/CN114825661B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20170059391A (en) * | 2015-11-20 | 2017-05-30 | 숭실대학교산학협력단 | Double sided resonant converter for wireless charger and method for implementing thereof |
| CN107425610A (en) * | 2017-05-10 | 2017-12-01 | 北京交通大学长三角研究院 | Radio energy transmission system and control method based on energy resource system load compensation in parallel |
| CN109474081A (en) * | 2018-09-06 | 2019-03-15 | 西安理工大学 | Based on radio energy transmission system constant current-constant voltage output characteristic charging method |
| CN110429720A (en) * | 2019-08-20 | 2019-11-08 | 南京航空航天大学 | A kind of induction type radio energy transmission system for realizing constant current constant voltage output switching |
| CN110855020A (en) * | 2019-11-11 | 2020-02-28 | 暨南大学 | Constant-voltage wireless charging system based on LCCL-LC compensation and parameter design method |
| CN112202251A (en) * | 2020-12-04 | 2021-01-08 | 南京航空航天大学 | Compensation parameter design method of wireless power transmission circuit capable of self-adapting and full tuning |
Non-Patent Citations (2)
| Title |
|---|
| 基于双LCC谐振的无线电能传输***设计;王付胜;王文洋;郭娟娟;张兴;;电力电子技术;20200120(第01期);全文 * |
| 电动汽车无线充电仿真***优化设计;付晶;龚国庆;陈勇;马士然;;计算机仿真;20181115(第11期);全文 * |
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| CN113364141A (en) | 2021-09-07 |
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