CN114899928A - Wireless charging device and method - Google Patents

Wireless charging device and method Download PDF

Info

Publication number
CN114899928A
CN114899928A CN202210444612.4A CN202210444612A CN114899928A CN 114899928 A CN114899928 A CN 114899928A CN 202210444612 A CN202210444612 A CN 202210444612A CN 114899928 A CN114899928 A CN 114899928A
Authority
CN
China
Prior art keywords
wireless charging
signal
controlled switch
transmitting coil
circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210444612.4A
Other languages
Chinese (zh)
Inventor
童彦彰
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dongguan Tailing Electric Vehicle Co ltd
Huayi Semiconductor Shenzhen Co ltd
Original Assignee
Dongguan Tailing Electric Vehicle Co ltd
Huayi Semiconductor Shenzhen Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dongguan Tailing Electric Vehicle Co ltd, Huayi Semiconductor Shenzhen Co ltd filed Critical Dongguan Tailing Electric Vehicle Co ltd
Publication of CN114899928A publication Critical patent/CN114899928A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • 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
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/02—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from ac mains by converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/42—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to product of voltage and current
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H5/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal non-electric working conditions with or without subsequent reconnection
    • H02H5/04—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal non-electric working conditions with or without subsequent reconnection responsive to abnormal temperature
    • 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
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M7/219—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only in a bridge configuration
    • 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
    • Y02T90/14—Plug-in electric vehicles

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)

Abstract

The invention provides wireless charging equipment and a wireless charging method. This wireless charging equipment includes: a wireless charging transmitting coil; the switching circuit is characterized in that two power supply input ends of the switching circuit are respectively connected to two input ends of an alternating current power supply, the switching circuit comprises 2N controlled switches, and N is more than or equal to 1; the driving signal demodulator is provided with 2N signal output ends which are respectively connected to the controlled ends of the corresponding controlled switches in the switch circuit and used for generating control signals for controlling the 2N controlled switches in the switch circuit to be respectively switched on or switched off; under the control of 2N control signals output by the driving signal demodulator, 2N controlled switches of the switch circuit are controlled to be switched on and off, and an alternating current charging signal is generated and loaded to the wireless charging transmitting coil. The circuit required by the invention is greatly simplified, the loss caused by power conversion is also greatly reduced, and the power conversion efficiency from the mains supply input to the wireless charging receiver is far higher than 95%.

Description

Wireless charging device and method
Technical Field
The invention relates to the technical field of wireless charging, in particular to wireless charging equipment and a wireless charging method.
Background
Under the current general wireless charging architecture, the power supply charging process starts to input an alternating current power supply from commercial power, the alternating current power supply is converted into a direct current power supply through a bridge, the direct current power supply is converted into the alternating current power supply through PFC or LLC technology, the alternating current power supply changes alternating current output voltage through an alternating current voltage converter, finally the alternating current power supply is converted into the direct current power supply through the bridge, and a wireless charging control chip converts the direct current power supply into a wireless charging alternating current signal and transmits the wireless charging alternating current signal to a charged device through a wireless charging transmitting coil. However, such a method results in low wireless charging efficiency, high required source power, high temperature in the energy transfer process, reduced lifespan of the electronic product, and high production cost.
Disclosure of Invention
Technical problem to be solved
The present invention seeks to solve at least partly at least one of the above technical problems.
(II) technical scheme
In order to achieve the above object, according to one aspect of the present invention, there is provided a wireless charging apparatus including: a wireless charging transmitting coil; the switching circuit is characterized in that two power supply input ends of the switching circuit are respectively connected to two input ends of an alternating current power supply, the switching circuit comprises 2N controlled switches, and N is more than or equal to 1; the driving signal demodulator is provided with 2N signal output ends which are respectively connected to the controlled ends of the corresponding controlled switches in the switch circuit and used for generating control signals for controlling the 2N controlled switches in the switch circuit to be respectively switched on or switched off; under the control of 2N control signals output by the driving signal demodulator, 2N controlled switches of the switch circuit are controlled to be switched on and switched off, so that the input alternating current is subjected to alternating current-to-alternating current processing, an alternating current charging signal is generated and loaded to the wireless charging transmitting coil.
In some embodiments of the present invention, the switching circuit is a bridge driver circuit comprising 2N controlled switches.
In some embodiments of the present invention, N ═ 2, the switching circuit is a full bridge driving circuit, including: a first switch group and a second switch group; wherein, the first switch group includes: the rear ends of the first controlled switch and the second controlled switch are respectively connected to a first terminal and a second terminal of an alternating current power supply, and the front ends of the first controlled switch and the second controlled switch are commonly connected to a first terminal of the wireless charging transmitting coil; the second switch group includes: the rear ends of the third controlled switch and the fourth controlled switch are respectively connected with the first terminal and the second terminal of the alternating current power supply, and the front ends of the third controlled switch and the fourth controlled switch are connected to the second terminal of the wireless charging transmitting coil through a matching capacitor; the first controlled switch, the second controlled switch, the third controlled switch and the fourth controlled switch are respectively controlled by a first control signal, a second control signal, a third control signal and a fourth control signal.
In some embodiments of the present invention, N ═ 2, the switching circuit is a full bridge driving circuit, including: a third switch group and a fourth switch group; wherein the third switch group includes: the rear end of the fifth controlled switch is connected to the first terminal of the alternating current power supply, the rear end of the sixth controlled switch is grounded, and the front ends of the fifth controlled switch and the sixth controlled switch are commonly connected to the first terminal of the wireless charging transmitting coil; the fourth switch group includes: the rear end of the seventh controlled switch is grounded, the rear end of the eighth controlled switch is connected to the second terminal of the alternating current power supply, and the front ends of the seventh controlled switch and the eighth controlled switch are connected to the second terminal of the wireless charging transmitting coil through a matching capacitor; the fifth controlled switch, the sixth controlled switch, the seventh controlled switch and the eighth controlled switch are respectively controlled by a first control signal, a second control signal, a third control signal and a fourth control signal.
In some embodiments of the present invention, the first control signal, the second control signal, the third control signal, and the fourth control signal are square wave signals, and the corresponding controlled switch is turned on at a high level and turned off at a low level of the square wave signals; the first control signal, the second control signal, the third control signal and the fourth control signal have the same frequency, the duty ratios of the four control signals are the same, the phases of the first control signal and the fourth control signal are the same, the phases of the second control signal and the third control signal are the same, and the high levels of the first control signal and the second control signal are staggered.
In some embodiments of the present invention, N ═ 1, the second terminal of the wireless charging transmit coil is grounded through the matching capacitor; the switching circuit is a half-bridge driving circuit, including: the rear ends of the ninth controlled switch and the tenth controlled switch are respectively connected to the first terminal and the second terminal of the alternating current power supply, and the front ends of the ninth controlled switch and the tenth controlled switch are commonly connected to the first terminal of the wireless charging transmitting coil; the ninth controlled switch and the tenth controlled switch are controlled by a first control signal and a second control signal respectively.
In some embodiments of the present invention, the first control signal and the second control signal are square wave signals, and the corresponding controlled switch is turned on under the condition of high level of the square wave signals and turned off under the condition of low level of the square wave signals; the first control signal and the second control signal have the same frequency, the duty ratio of the first control signal and the second control signal is the same, and the high levels of the first control signal and the second control signal are staggered.
In some embodiments of the invention, the controlled switch is a GaN semiconductor switch with a breakdown voltage higher than 220V.
In some embodiments of the present invention, the frequency of the control signal is between 80kHz and 150kHz, and the duty cycle is between 20% and 50%.
In some embodiments of the invention, further comprising: the rectifier circuit is connected with a first terminal and a second terminal of an alternating current power supply at two input ends respectively, and connected with a power supply port of a control power supply at an output end for converting alternating current of the alternating current power supply into direct current; and the power supply port of the control circuit is connected to the output end of the rectifying circuit, the output end of the control circuit is connected to the input end of the driving signal demodulator, and the control circuit is used for generating a driving signal for driving the driving signal demodulator, wherein the driving signal comprises information of the frequency and the duty ratio of the control signal.
In some embodiments of the invention, further comprising: the current detector is used for detecting the current flowing through the wireless charging transmitting coil; the temperature detector is used for detecting the temperature of the wireless charging transmitting coil; a feedback circuit comprising two signal inputs: the first signal input end is electrically connected to a first terminal of the wireless charging transmitting coil to obtain a voltage signal AC 1; a second signal input end of the wireless charging transmitting coil is electrically connected to a second terminal of the wireless charging transmitting coil to obtain a voltage signal AC 2; the signal output end of the voltage signal AC1' is connected to the control circuit, and the voltage signal AC1' and the voltage signal AC2' which meet the signal input requirement of the control circuit are obtained by carrying out voltage reduction and noise reduction on the voltage signal AC1 and the voltage signal AC2 and are input to the control circuit; a control circuit, a first signal input end of which is connected to the feedback circuit, a second signal input end of which is connected to the current detector, and a third signal input end of which is connected to the temperature detector, for obtaining the voltage information of the wireless charging transmitting coil from the voltage signal AC1 'and the voltage signal AC2', and obtaining the current information of the wireless charging transmitting coil from the input of the current detector; the temperature information of the wireless charging transmitting coil is obtained through the input of the temperature detector, and the driving signal is adjusted according to the voltage information, the current information and the temperature information of the wireless charging transmitting coil.
In order to achieve the above object, according to a second aspect of the present invention, there is also provided a wireless charging method, performed by a control circuit in the above wireless charging apparatus, including:
step A, acquiring charging power threshold information of a charged device;
step B, under the condition of meeting the charging power threshold of the charged equipment, increasing the charging power by adopting a mode that the switching frequency gradually approaches to the resonance frequency of the wireless charging equipment;
wherein the resonant frequency of the wireless charging device
Figure BDA0003616102410000031
L is the inductance value of wireless transmitting coil that charges, and C is the capacitance value of matching the electric capacity.
In some embodiments of the present invention, the resonant frequency of the wireless charging device is set between 80kHz and 100 kHz; in step B, the initial value of the switching frequency is set to be higher than 120 kHz.
In some embodiments of the invention, the wireless charging device further comprises: the current detector is used for detecting the current flowing through the wireless charging transmitting coil; the temperature detector is used for detecting the temperature of the wireless charging transmitting coil; a feedback circuit comprising two signal inputs: the first signal input end is electrically connected to a first terminal of the wireless charging transmitting coil to obtain a voltage signal AC 1; a second signal input end of the wireless charging transmitting coil is electrically connected to a second terminal of the wireless charging transmitting coil to obtain a voltage signal AC 2; the signal output end of the voltage signal AC1' is connected to the control circuit, and the voltage signal AC1' and the voltage signal AC2' which meet the input requirement of the control current signal are obtained by carrying out voltage reduction and noise reduction on the voltage signal AC1 and the voltage signal AC2 and are input to the control circuit; a control circuit, a first signal input end of which is connected to the feedback circuit, a second signal input end of which is connected to the current detector, and a third signal input end of which is connected to the temperature detector;
the step A comprises the following steps: obtaining information of the charging power threshold transmitted by the charged device from the voltage signal AC1 'and the voltage signal AC 2';
step B also comprises the following steps:
step C, under the condition of meeting the charging power threshold of the charged equipment, increasing the charging power by adopting a mode of gradually increasing the duty ratio of the control signal;
step D, acquiring real-time operation information of the wireless charging equipment, including: obtaining voltage information of the wireless charging transmitting coil from the voltage signal AC1 'and the voltage signal AC 2'; obtaining current information of the charging transmitting coil from the input of the current detector; acquiring the actual charging power of the wireless charging equipment according to the voltage information and the current information of the wireless charging transmitting coil; obtaining the temperature information of the wireless charging transmitting coil through the input of the temperature detector;
step E, when one of the following conditions occurs, sending a driving signal to the driving signal demodulator to enable each controlled switch to be switched into a disconnected state:
the temperature of a wireless charging transmitting coil exceeds a preset temperature threshold;
the current of the wireless charging transmitting coil exceeds a preset current threshold value;
and thirdly, the actual charging power of the wireless charging equipment exceeds the charging power threshold of the charged equipment or fluctuates by more than 10%.
(III) advantageous effects
According to the technical scheme, the invention has at least one of the following beneficial effects:
(1) the alternating current signal of the commercial power is converted into the alternating current signal required by the wireless charging through the switching action of the controlled switch in the switch circuit, the required circuit is greatly simplified, the loss caused by power conversion is greatly reduced, and the power conversion efficiency from the commercial power input to the wireless charging receiver is far higher than 95%.
(2) The GaN switch capable of bearing high voltage is adopted, and the requirements of voltage improvement and high power of the wireless charging equipment can be met.
(3) The charging power is controlled through the switching frequency and the duty ratio of the four controlled switches, and the method is simple and effective.
(4) In the initial situation, a higher switching frequency is adopted for charging, then the switching frequency is gradually close to the resonant frequency of the charging equipment, the transmission power is closer to the resonant frequency, the output power is higher, and the highest transmission power exists when the switching frequency is equal to the resonant frequency, so that the charging speed is improved under the condition of meeting the safety of the equipment.
(5) The control circuit can master the real-time change of the charging power and the current and temperature information of the wireless charging transmitting coil in real time, and accordingly the switching frequency is adjusted, and the actual charging power is adjusted.
(6) A protection mechanism is arranged in the control circuit, and when the actual charging power, the charging current and the coil temperature exceed the safety threshold, the four controlled switches are switched off, so that the personal safety and the equipment safety can be very simply ensured.
Drawings
Fig. 1 is an overall architecture diagram of a first embodiment of the wireless charging device of the present invention.
Fig. 2 is a schematic structural diagram of a control circuit, a driving signal demodulator and a switch circuit in the wireless charging device shown in fig. 1.
Fig. 3 is a timing diagram of the driving signal and the control square wave in the wireless charging device shown in fig. 1.
Fig. 4 is a waveform diagram of an ac charging signal applied to the wireless charging transmitting coil by the switching circuit in the wireless charging device shown in fig. 1 under the driving of the control square wave shown in fig. 3.
Fig. 5 is a schematic structural diagram of a control circuit in the wireless charging device shown in fig. 1.
Fig. 6 is a flowchart of an embodiment of a wireless charging method based on the wireless charging device shown in fig. 1.
Fig. 7 is a schematic structural diagram of a driving signal demodulator, a switching circuit, a wireless charging transmitting coil and the like in a second embodiment of the wireless charging device of the present invention.
Fig. 8 is a schematic structural diagram of a driving signal demodulator, a switching circuit, a wireless charging transmitting coil and the like in a third embodiment of the wireless charging device of the present invention.
Detailed Description
In the wireless charging equipment and the method, the commercial power alternating current power supply is converted into the alternating current signal required by the wireless charging through the switching actions of the four controlled switches in the switch circuit, the required circuit is greatly simplified, the loss caused by power conversion is minimum, and the power conversion efficiency is greatly improved.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings.
In one exemplary embodiment of the present invention, a wireless charging device is provided. Fig. 1 is an overall architecture diagram of a first embodiment of the wireless charging device of the present invention. Fig. 2 is a schematic structural diagram of a control circuit, a driving signal demodulator and a switch circuit in the wireless charging device shown in fig. 1. The wireless charging device and the corresponding charged device of the present embodiment are explained below with reference to fig. 1 and 2.
As shown in fig. 1, the charging system includes: wireless charging equipment, by charging equipment. The wireless charging receiving coil receives energy from the wireless charging transmitting coil through electromagnetic induction to generate alternating current power output; the charged device converts the alternating current power output into direct current power output to charge a corresponding battery or directly supply power to the corresponding device.
As shown in fig. 1, the wireless charging apparatus of the present embodiment includes: the wireless charging transmitting coil, the rectifying circuit, the control circuit, the driving signal demodulator, the switching circuit and the feedback circuit. Wherein:
the rectifier circuit has two input ends connected to the first terminal and the second terminal of the AC power supply, and an output end connected to the power port of the control power supply for converting the AC power supply into DC power suitable for the control circuit.
And a power supply port of the control circuit is connected to the output end of the rectifying circuit, the output end of the control circuit is connected to the input end of the driving signal demodulator, and the control circuit is used for generating a driving signal for driving the driving signal demodulator, wherein the driving signal comprises information of the frequency and the duty ratio of the control signal.
And the input end of the driving signal demodulator is connected to the output end of the control circuit, and 4 signal output ends of the driving signal demodulator are respectively connected to the controlled ends of the corresponding controlled switches and used for generating control signals for controlling the on or off of the 4 controlled switches in the switch circuit according to the driving signals.
And the switch circuit is a full-bridge drive circuit comprising 4 controlled switches, the two power input ends of the switch circuit are respectively connected to the two input ends of the alternating current power supply, and the output end of the switch circuit is connected to the wireless charging transmitting coil.
And the sensing end of the feedback circuit is connected to the control circuit and is used for monitoring the wireless charging signal, processing the monitoring signal and then sending the processed monitoring signal to the control circuit, and adjusting the driving signal by the control circuit to achieve the purpose of adjusting the wireless charging process in real time.
The control circuit is powered by direct current output by the rectifying circuit to generate a driving signal; under the drive of the drive signal, under the control of the 2N control signals output by the drive signal demodulator, the 2N controlled switches of the switch circuit are controlled and independently switched on and off, so that the input alternating current is subjected to alternating current-to-alternating current processing, an alternating current charging signal is generated and loaded to the wireless charging transmitting coil.
The respective components of the present embodiment are explained in detail below.
In this embodiment, the ac mains supply is a common mains supply, and has an effective voltage value of 220V and a frequency of 50 Hz. Of course, the invention is equally applicable to other types of alternating current and will not be described in detail here.
In this embodiment, the rectifier circuit includes: an AC-to-DC bridge and a DC filter. The alternating current-to-direct current bridge is used for converting alternating current input into direct current output, and the direct current filter is used for filtering noise waves in output voltage. For the ac-dc bridge and the dc filter, reference may be made to the related descriptions in the prior art, and the description thereof is omitted here.
The following two points need to be particularly described for the rectifier circuit:
1. the rectifying circuit only supplies power for the control circuit
The alternating current power supply of the commercial power converts alternating current into direct current through the rectifying circuit, and the direct current is only supplied to the control circuit, so the required conversion power is far less than 0.1W, the manufacturing cost and the power consumption of the alternating current-to-direct current bridge are greatly reduced, and the heat energy generated by the alternating current-to-direct current bridge is lower than one percent of that of related circuits in the prior art.
2. The rectifying circuit does not directly supply power for the wireless charging transmitting coil
The switch circuit directly uses the commercial power alternating current power supply to process, outputs a wireless charging signal and transmits the wireless charging signal to the charged equipment through the wireless charging transmitting coil, and finally outputs a direct current power supply to be used by an electronic product. In other words, the switching circuit in the present invention is an ac charging signal directly generated by ac → ac processing of ac power without processing for converting ac power into dc power, which is also an important feature of the present invention distinguished from the prior art.
Referring to fig. 2, the switch circuit is a full bridge driving circuit, including: a first switch set and a second switch set. The first switch group includes: the rear ends of the first controlled switch K1 and the second controlled switch K2 are respectively connected to the first terminal and the second terminal of the mains supply alternating current power supply input, and the front ends of the first controlled switch K1 and the second controlled switch K2 are commonly connected to the first terminal of the wireless charging transmitting coil. The second switch group includes: and the rear ends of the third controlled switch K3 and the fourth controlled switch K4 are respectively connected with the first terminal and the second terminal of the alternating current power supply, and the front ends of the third controlled switch K3 and the fourth controlled switch K4 are commonly connected to the second terminal of the wireless charging transmitting coil through a matching capacitor C.
It should be noted that the switch circuit of this embodiment is a full-bridge drive circuit including four controlled switches, a second embodiment of the following wireless charging device will provide a full-bridge drive circuit in which the switch circuit adopts another form, and a third embodiment of the wireless charging device will provide a half-bridge drive circuit in which the switch circuit adopts two controlled switches, which will be described in detail below.
As will be appreciated by those skilled in the art, the present invention provides the most significant advantages in terms of cost, conversion efficiency, and overall system size, as the voltage of the conventional wireless charging circuit is increased, and thus, design adjustments and changes are required to meet the high voltage and high power requirements.
Specifically, for the controlled switch connected to the two ends of the wireless charging transmitting coil, the other end is directly connected to the mains supply, so the device and circuit design must be able to withstand the mains supply voltage, which is 220V in china. In this embodiment, all 4 controlled switches need to withstand a voltage higher than 220V, and a common switch cannot be adopted, so that a GaN switch capable of withstanding a high voltage is adopted, and the requirements of voltage improvement and high power of the wireless charging device can be met.
In addition, for the wireless charging device of the present embodiment, L is the inductance value of the wireless charging transmitting coil, and C is the capacitance value of the matching capacitor, so the resonant frequency of the wireless charging device
Figure BDA0003616102410000071
This will be explained in detail below.
The signal input end of the driving signal demodulator is connected to the control circuit, and the four signal output ends of the driving signal demodulator are respectively connected to the control ends of the first controlled switch, the second controlled switch, the third controlled switch and the fourth controlled switch, and are used for outputting according to the driving signals: a first control signal controlling the first controlled switch K1, a second control signal controlling the second controlled switch K2, a third control signal controlling the third controlled switch K3, a fourth control signal controlling the fourth controlled switch K4. The driving signal includes information of frequency and duty ratio of the control side wave.
Fig. 3 is a timing diagram of the driving signal and the control square wave in the wireless charging device shown in fig. 1. Referring to fig. 3, TC is a waveform of the driving signal, and TC1, TC2, TC3 and TC4 are waveforms of the first, second, third and fourth control signals, respectively. Since the four control signals are all square waves, for the sake of simplicity, the description of "control square waves" is provided later. The first controlled switch, the second controlled switch, the third controlled switch and the fourth controlled switch are all switched on under the condition of high potential of a control square wave and are switched off under the condition of low potential.
As shown in fig. 3, the frequencies of the first, second, third and fourth control square waves are the same as the frequency of the driving signal. And the switching frequency of the first control square wave, the second control square wave, the third control square wave and the fourth control square wave is the same, and the duty ratio of the first control square wave, the second control square wave, the third control square wave and the fourth control square wave is the same.
The first control square wave and the fourth control square wave have the same phase, the second control square wave and the third control square wave have the same phase, and the first control square wave and the second control square wave are staggered. The term "staggered" means: TC1 and TC2 do not conduct the controlled switch at the same time, since the simultaneous conduction causes a very large leakage current, which causes the switch to burn out; likewise, TC3 and TC4 do not turn on the controlled switch at the same time.
The frequency of the first control square wave, the frequency of the second control square wave, the frequency of the third control square wave and the frequency of the fourth control square wave are between 80kHz and 150kHz, and the duty ratio is between 20% and 50%. Correspondingly, the switching frequency of the first controlled switch, the second controlled switch, the third controlled switch and the fourth controlled switch is between 80kHz and 150 kHz; the duty cycle is between 20% and 50%.
The inductance value of the wireless charging transmitting coil and the capacitance value of the matching capacitor connected in series with the wireless charging transmitting coil determine the resonant frequency of the system, when the driving frequency is gradually reduced from being higher than the resonant frequency to being close to the resonant frequency, the transmission power is larger as the output power is closer to the resonant frequency, the highest transmission power exists at the resonant frequency, the resonant frequency is designed to be about 80-90 kHz at the high power at present, and the initial driving frequency is set to be more than 120 kHz.
According to the general expression method in the field, the ratio of the conduction time to the signal period, which is called the Duty ratio (Duty%) of the waveform, according to the experiments of the applicant, about 50% to 30% has no influence on the output power, and when the percentage is lower than 30% at the beginning, the lower percentage causes the output power to decrease, thereby achieving the purpose of controlling the output power.
Based on the above discussion, the output power of the switching circuit can be adjusted by adjusting the frequency and/or duty cycle of the control-side wave. However, it is more convenient to adjust the frequency of the control square wave, so in this embodiment, it is preferable to adjust the output power of the switching circuit by adjusting the frequency of the control square wave.
And under the control of the corresponding control square wave, the four controlled switches are switched on and off according to a preset frequency. The switching frequencies of the first controlled switch, the second controlled switch, the third controlled switch and the fourth controlled switch are the same; the conducting periods of the first controlled switch and the fourth controlled switch are overlapped, and the conducting periods of the second controlled switch and the third controlled switch are overlapped; the conduction periods of the first controlled switch and the second controlled switch are staggered with each other, and the conduction periods of the third controlled switch and the fourth controlled switch are staggered with each other.
Fig. 4 is a waveform diagram of an ac charging signal applied to the wireless charging transmitting coil by the switching circuit in the wireless charging device shown in fig. 1 under the driving of the control square wave shown in fig. 3. As shown in fig. 4, the ac charging signal is an ac signal having an envelope of both the ac power waveform and the inverted waveform thereof, and is fundamentally different from the ac charging signal applied to the ac charging coil in the related art.
An ac charging signal as shown in fig. 4 is loaded in the wireless charging transmitting coil, and energy is transmitted to the charged device through the principle of electromagnetic induction. As can be understood from the transfer process of the energy for charging, the energy conversion transfer mode of the wireless charging device of the embodiment has the following advantages:
1. greatly improving the power conversion efficiency
In the present embodiment, the switching operation of the switch circuit is converted into the ac frequency required for the wireless charging, so that the circuit is simplified to the minimum, the loss caused by the power conversion is also minimized, and the power conversion efficiency from the commercial power input to the wireless charging receiver is much higher than 95%. The practical design has more obvious advantages in high-power wireless charging application.
2. Heat generation reduction
Because the commercial power is directly converted into the charging power supply, the output can be far higher than that of other designs in power conversion, the conversion efficiency is very excellent, and the heating problem is far lower than that of other designs.
3. The circuit is greatly simplified
The wireless charging device has the obvious advantage of great structure, the alternating current power supply of the commercial power is directly converted into the direct current power supply in design and is directly output to the wireless charging transmitting coil, the required circuit elements are greatly reduced, and the cost of the wireless charging device is favorably reduced.
It should be specifically noted that although the control of the four controlled switches is implemented by generating the control square wave through the driving signal demodulator in the present embodiment, it should be understood by those skilled in the art that the control signal may also be generated in other manners, for example, by using a delay design, and details are not described herein.
It should be noted that although the amplitude of the voltage applied to the two ends of the wireless charging transmitting coil also affects the transmission power, the amplitude of the commercial power is mainly used as the amplitude of the charging coil in the present invention, so as to maximize the efficiency of the transmission power, and the adjustment of the amplitude of the voltage at the two ends of the wireless charging transmitting coil is not involved.
Referring to fig. 1, the wireless charging apparatus of the present embodiment further includes: the feedback circuit comprises two signal input ends, wherein the first signal input end of the two signal input ends is electrically connected to the first terminal of the wireless charging transmitting coil to obtain a voltage signal AC 1; a second signal input end of the wireless charging transmitting coil is electrically connected to a second terminal of the wireless charging transmitting coil to obtain a voltage signal AC 2; the signal output end of the voltage signal AC1' is connected to the control circuit, and the voltage signal AC1' and the voltage signal AC2' which meet the input requirement of the control current signal are obtained by carrying out voltage reduction and noise reduction on the voltage signal AC1 and the voltage signal AC2, and the voltage signal AC1' and the voltage signal AC2' are input to the control circuit.
It will be understood by those skilled in the art that the voltage signals AC1 and AC2 are derived from both ends of the wireless charging transmit coil, and are at a higher voltage and contain a significant amount of insignificant noise. The feedback circuit is used for filtering and reducing the high-voltage noise signals into feedback signals-AC 1 'and AC2' which can be analyzed by the control circuit and are transmitted to the control circuit.
In this embodiment, the wireless charging device further includes: a current detector for detecting the current flowing through the wireless charging transmitting coil to generate a coil current signal S I (ii) a A temperature detector for detecting the temperature of the wireless charging transmitting coil to generate a coil temperature signal S T . Coil current signal S I And a coil temperature signal S T And is input to the control circuit. The current detector is, for example, a hall detector. The temperature detector can use the temperature detection circuit in the prior art。
Fig. 5 is a schematic structural diagram of a control circuit in the wireless charging device shown in fig. 1. Referring to fig. 2 and 5, the control circuit includes:
an analog front end circuit having three signal input terminals and having a signal amplification circuit therein for analog amplification of three types of signals, the three signal input terminals including:
the first signal input end is connected to the feedback circuit and receives feedback signals-AC 1 'and AC 2';
the second signal input terminal is connected to the current detector for receiving the coil current signal S I ；
A third signal input terminal connected to the temperature detector for receiving the coil temperature signal S T ；
An analog-to-digital converter (ADC) which receives the three types of signals after analog amplification and converts them into digital signals;
and the judging charging control circuit (microprocessor, MCU) is used for adjusting the driving signal according to the voltage information, the current information and the temperature information of the wireless charging transmitting coil.
In this embodiment, the voltage information AC1 and AC2 are demodulated by the detection circuit and then input to the control circuit, and the control circuit calculates the output voltage and the feedback information of the receiving end based on the demodulated voltage information to adjust the output power. The amplitude of the AC1 and the AC2 changes when the charged device receives the power, the charged device can also change the received power by using the load, the received power changes to cause the AC1 and the AC2 to transmit the information of the charged device to the wireless charging device, the wireless charging device uses the information to control the driving frequency or the waveform percentage, etc., and transmits the power to the charged device, if the control circuit detects and determines that the abnormal charging phenomenon occurs, the driving signal is terminated to stop the charging service.
Based on the wireless charging equipment, the invention also provides a wireless charging method. The entire contents described in the wireless charging apparatus are incorporated in the present embodiment as a part of the present embodiment.
The wireless charging method of the embodiment is realized by a control circuit, specifically by a judging charging control circuit therein. In the wireless charging method, a feedback signal of a wireless charging transmitting coil and signals of voltage, current, temperature detection and the like are transmitted to a control circuit. The control circuit controls the wireless charging according to the signals, and comprises: firstly, power control is carried out; ② the control is interrupted.
Fig. 6 is a flowchart of an embodiment of a wireless charging method based on the wireless charging device shown in fig. 1. Referring to fig. 6, the wireless charging method of the present embodiment includes:
step A, acquiring charging power threshold information of a charged device;
as will be appreciated by those skilled in the art, the wireless charging device and the charged device may perform information interaction via the transmitting coil/receiving coil, the interaction information is loaded into the induced electromagnetic wave, and the information transmitted by the charged device is embodied on the voltages of the first terminal and the second terminal of the wireless charging transmitting coil. Therefore, the information transmitted by the charged device can be analyzed through the voltage signal AC1 'and the voltage signal AC 2'.
Specifically, the charged device (RX) with general specification intentionally generates load variation, and information is hidden in the voltage variation, so that the two signals can be detected by communication, and the charging power threshold information of the charged device can be obtained from the two signals. Of course, the wireless charging device and the charged device may also perform information interaction in other manners, for example, in a bluetooth manner.
In this embodiment, step a includes: the information of the charging power threshold transmitted by the charged device is obtained by the voltage signal AC1 'and the voltage signal AC 2'.
Step B, under the condition of meeting the charging power threshold of the charged equipment, gradually increasing the charging power by adopting a mode that the switching frequency gradually approaches to the resonance frequency of the wireless charging equipment;
step C, under the condition of meeting the charging power threshold of the charged equipment, gradually increasing the charging power by adopting a mode of gradually increasing the duty ratios of the first to fourth control square waves;
what is meant by steps B and C above is that: the invention preferentially adopts a mode of adjusting the switching frequency to adjust the charging power. As will be appreciated by those skilled in the art, the wireless charging power may be adjusted by adjusting the duty cycle. However, in practical engineering, the applicant finds that adjusting the duty ratio is complicated and causes other problems, and therefore, the wireless charging power is first adjusted by adjusting the switching frequency.
Referring to fig. 3, the high potential of the control square wave turns on the controlled switch, and the low potential turns off the controlled switch. TC1 and TC2 do not conduct the controlled switch at the same time, which would cause a very large leakage current, which would cause the switch to burn out; likewise, TC3 and TC4 do not conduct simultaneously. The ratio of the on time to the period of the driving frequency, called as the Duty ratio (Duty%) of the waveform, is about 50% to 30% without influence on the output power, and when the Duty ratio is lower than 30%, the lower percentage causes the output power to decrease gradually, thereby achieving the purpose of controlling the output power.
The inductance L of the wireless charging transmitting coil and the capacitance C of the matching capacitor connected in series therewith determine the resonant frequency of the wireless charging device, that is:
Figure BDA0003616102410000121
when the driving frequency is gradually reduced from higher than the resonance frequency to be close to the resonance frequency, the transmission power is closer to the resonance frequency, the output power is larger, the highest transmission power exists at the resonance frequency, the resonance frequency is designed to be about 80-90 kHz at the present high power, the initial driving frequency is set to be more than 120kHz, and the driving frequency and the waveform percentage are adjusted according to the power required by the receiver. Although the amplitudes of AC1 and AC2 also affect the transmission power, the amplitude of the commercial power is mainly used as the amplitude of the wireless charging transmitting coil, so that the transmission power efficiency is the highest.
Step D, acquiring real-time operation information of the wireless charging equipment, including:
a substep D1, obtaining the temperature information of the wireless charging transmitting coil from the input of the temperature detector;
a substep D2, obtaining the current information of the charging transmitting coil from the input of the current detector;
a sub-step D3 of obtaining voltage information of the wireless charging transmitting coil from the voltage signal AC1 'and the voltage signal AC 2';
and a substep D4, obtaining actual charging power information of the wireless charging device according to the voltage information and the current information of the wireless charging transmitting coil.
Changes in the power drawn by the charged device can cause changes in the load on the wireless charging transmit coil, which in turn causes changes in the voltage signals AC1 and AC 2. The detection voltage signals AC1 and AC2 can be aware of the wireless charging power output variation. In addition, in a typical 15W or other low power transmission, the current is converted from the two signals, so the current can also be measured, but this causes extra energy loss, heat generation, and so the current is tested in other ways in a high power wireless charging device.
Step E, when one of the following conditions occurs, sending a driving signal to enable the first controlled switch, the second controlled switch, the third controlled switch and the fourth controlled switch to be switched into an off state, and ending charging:
the temperature of a wireless charging transmitting coil exceeds a preset temperature threshold;
the current of the wireless charging transmitting coil exceeds a preset current threshold;
and thirdly, the actual charging power of the wireless charging equipment exceeds the charging power threshold of the charged equipment or fluctuates by more than 10%.
In this embodiment, through the signal input end of the control circuit, the real-time change of the charging power, the current and temperature information of the wireless charging transmitting coil can be grasped in real time, and the switching frequency is adjusted accordingly, so as to adjust the actual charging power. Meanwhile, the control circuit is provided with a protection mechanism, and when the actual charging power, the charging current and the coil temperature exceed the safety threshold, the four switches are disconnected, so that the personal safety and the equipment safety can be very simply ensured.
In a second embodiment of the present invention, another wireless charging device is provided. The present embodiment is different from the wireless charging apparatus shown in fig. 2 in that: the switch circuit adopts another full-bridge drive circuit.
Fig. 7 is a schematic structural diagram of a driving signal demodulator, a switching circuit, a wireless charging transmitting coil and the like in a second embodiment of the wireless charging device of the present invention. As shown in fig. 7, the switching circuit in the present embodiment includes: a third switch group and a fourth switch group; wherein,
the third switch group includes: a fifth controlled switch K5 and a sixth controlled switch K6, wherein the rear end of the fifth controlled switch K5 is connected to the first terminal of the ac power supply, the rear end of the sixth controlled switch K6 is grounded, and the front ends of the fifth controlled switch K5 and the sixth controlled switch K6 are commonly connected to the first terminal of the wireless charging transmitting coil;
the fourth switch group includes: a seventh controlled switch K7 and an eighth controlled switch K8, wherein the rear end of the seventh controlled switch K7 is grounded, the rear end of the eighth controlled switch K8 is connected to the second terminal of the ac power supply, and the front ends of the seventh controlled switch K7 and the eighth controlled switch K8 are connected to the second terminal of the wireless charging transmitting coil in common through a matching capacitor C;
the fifth controlled switch K5, the sixth controlled switch K6, the seventh controlled switch K7, and the eighth controlled switch K8 are controlled by a first control signal, a second control signal, a third control signal, and a fourth control signal, respectively.
The present embodiment is the same as the first embodiment of the wireless charging device, and the first control signal, the second control signal, the third control signal, and the fourth control signal are square wave signals, and the corresponding controlled switches are turned on under the condition of high level of the square wave signals and turned off under the condition of low level; the first control signal, the second control signal, the third control signal and the fourth control signal have the same frequency, the duty ratios of the four control signals are the same, the phases of the first control signal and the fourth control signal are the same, the phases of the second control signal and the third control signal are the same, and the high levels of the first control signal and the second control signal are staggered. Regarding the four control signals, reference may also be made to the timing diagram of the driving signal and the control square wave shown in fig. 3, which is not described herein again.
It should be noted that this embodiment provides an implementation manner of a switching circuit including four controlled-switch full-bridge driving circuits, and in combination with another form of the full-bridge driving circuit in the first embodiment of the wireless charging device, a third embodiment of the subsequent wireless charging device will provide another solution for a switching circuit including a half-bridge driving circuit with two controlled switches.
Regarding the structures of the driving signal demodulator, the control circuit and the feedback circuit in this embodiment, reference may be made to the description of the first embodiment of the wireless charging device. As for the wireless charging method according to the present embodiment, the charging method according to the first embodiment of the wireless charging apparatus can be referred to. The contents of these two parts will not be described in detail here.
In a third embodiment of the present invention, another wireless charging device is provided. The present embodiment differs from the wireless charging device shown in fig. 2 and 7 in that: the switching circuit adopts a half-bridge driving circuit.
Fig. 8 is a schematic structural diagram of a driving signal demodulator, a switching circuit, a wireless charging transmitting coil and the like in a third embodiment of the wireless charging device of the present invention. As shown in fig. 8, the switching circuit in this embodiment is a half-bridge driving circuit, including: and the rear ends of the ninth controlled switch K9 and the tenth controlled switch K10 are respectively connected to the first terminal and the second terminal of the alternating current power supply, and the front ends of the ninth controlled switch K9 and the tenth controlled switch K10 are commonly connected to the first terminal of the wireless charging transmitting coil. And the second terminal of the wireless charging transmitting coil is grounded through a matching capacitor C.
In this embodiment, the ninth controlled switch K9 and the tenth controlled switch K10 are controlled by the first control signal TC1 and the second control signal TC2, respectively. For the first control signal TC1 and the second control signal TC2, reference may be made to fig. 3 and the related descriptions of the first embodiment of the wireless charging device at TC1 and TC2, which are not described herein again.
It should be noted that, in the first embodiment of the wireless charging device, the switching circuit employs a first full-bridge driving circuit, in the second embodiment of the wireless charging device, the switching circuit employs a second full-bridge driving circuit, and in the third embodiment of the wireless charging device, the switching circuit employs a half-bridge driving circuit. It should be understood by those skilled in the art that there may be other bridge driving circuits including 2N controlled switches besides the three bridge driving circuits, and it is also within the scope of the present invention to perform ac-to-ac processing on the input ac power to generate a wireless charging signal for the wireless charging transmitting coil.
Regarding the structures of the driving signal demodulator, the control circuit and the feedback circuit in this embodiment, reference may be made to the description of the first embodiment of the wireless charging device. As for the wireless charging method according to the present embodiment, the charging method according to the first embodiment of the wireless charging apparatus can be referred to. The contents of these two parts will not be described in detail here.
It should be noted that, since the second terminal of the wireless charging transmitting coil is grounded through the matching capacitor, in this embodiment, the charging voltage detection connector is connected only to the first terminal of the wireless charging transmitting coil, so as to obtain the voltage signal AC1, and the feedback circuit and the control circuit are adjusted accordingly. These are all the contents that can be known to those skilled in the art based on their own expertise, and are not described in detail herein.
So far, the detailed description has been given of the embodiments of the present invention with reference to the accompanying drawings. From the above description, those skilled in the art should clearly recognize the wireless charging apparatus and method of the present invention.
In summary, the wireless charging device and method provided by the invention realize ultra-high power transmission, reduce power consumption, improve power efficiency, save strict requirements of a heat dissipation system, avoid temperature problems, greatly reduce construction cost, and further popularize safety and convenience of wireless charging, thereby having strong practical value.
It is noted that for some implementations, if not essential to the invention and well known to those of ordinary skill in the art, they are not illustrated in detail in the drawings or in the text of the description, as they may be understood with reference to the relevant prior art.
Further, the foregoing examples are provided merely to enable the invention to meet the requirements of law, and the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Further, the above definitions of the various elements and methods are not limited to the various specific structures, shapes or arrangements of parts mentioned in the examples, which may be easily modified or substituted by those of ordinary skill in the art.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, e.g., as being fixed or detachable or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms can be understood in a specific case to those of ordinary skill in the art.
Unless expressly indicated to the contrary, the numerical parameters set forth in the specification and claims of this invention may be approximations that may vary depending upon the teachings of the invention. Specifically, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about," which is intended to be interpreted to include within its meaning a number of variations from the specified quantity, in some embodiments, by plus or minus 10%, in some embodiments, by plus or minus 5%, in some embodiments, by plus or minus 1%, and in some embodiments, by plus or minus 0.5%.
Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.
Ordinal numbers such as "first," "second," "third," "primary," "secondary," and arabic numerals, letters, etc., used in the specification and claims to modify a corresponding element or step are intended only to distinguish one element (or step) having a certain name from another element (or step) having the same name, and do not imply any ordinal number for the element (or step) nor the order of one element (or step) from another element (or step).
In addition, unless steps are specifically described or must occur in sequence, the order of the steps is not limited to that listed above and may be changed or rearranged as desired by the desired design. The embodiments described above may be mixed and matched with each other or with other embodiments based on design and reliability considerations, i.e., technical features in different embodiments may be freely combined to form further embodiments.
The algorithms and displays presented herein are not related to any particular computer, virtual system, or other native device. Various general purpose systems may also be used with the teachings herein. The required structure for constructing such a system will be apparent from the description above. Moreover, the present invention is not directed to any particular programming language. It is appreciated that a variety of programming languages may be used to implement the teachings of the present invention, and the foregoing descriptions of specific languages are provided for purposes of disclosure as best modes of practicing the invention.
The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. The various component embodiments of the invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that a microprocessor or Digital Signal Processor (DSP) may be used in practice to implement some or all of the functionality of some or all of the components in the associated apparatus according to embodiments of the invention. The present invention may also be embodied as apparatus or device programs (e.g., computer programs and computer program products) for performing a portion or all of the methods described herein. Such programs implementing the present invention may be stored on computer-readable media or may be in the form of one or more signals. Such a signal may be downloaded from an internet website or provided on a carrier signal or in any other form.
Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the method of the invention should not be construed to reflect the intent: the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (12)

1. A wireless charging device, comprising:
a wireless charging transmitting coil;
the switching circuit is characterized in that two power supply input ends of the switching circuit are respectively connected to two input ends of an alternating current power supply, the switching circuit comprises 2N controlled switches, and N is more than or equal to 1;
the driving signal demodulator is provided with 2N signal output ends which are respectively connected to the controlled ends of the corresponding controlled switches in the switch circuit and used for generating control signals for controlling the 2N controlled switches in the switch circuit to be respectively switched on or switched off;
under the control of the 2N control signals output by the driving signal demodulator, the 2N controlled switches of the switch circuit are controlled to be switched on and off, so that the input alternating current is subjected to alternating current-to-alternating current processing, an alternating current charging signal is generated and loaded to the wireless charging transmitting coil.
2. The wireless charging device of claim 1, wherein N-2, the switching circuit is a full bridge driving circuit comprising: a first switch group and a second switch group; wherein,
the first switch group includes: the rear ends of the first controlled switch and the second controlled switch are respectively connected to a first terminal and a second terminal of an alternating current power supply, and the front ends of the first controlled switch and the second controlled switch are commonly connected to a first terminal of the wireless charging transmitting coil;
the second switch group includes: the rear ends of the third controlled switch and the fourth controlled switch are respectively connected with a first terminal and a second terminal of an alternating current power supply, and the front ends of the third controlled switch and the fourth controlled switch are connected to the second terminal of the wireless charging transmitting coil through a matching capacitor;
the first controlled switch, the second controlled switch, the third controlled switch and the fourth controlled switch are respectively controlled by a first control signal, a second control signal, a third control signal and a fourth control signal.
3. The wireless charging device of claim 1, wherein N-2, the switching circuit is a full bridge driving circuit comprising: a third switch group and a fourth switch group; wherein,
the third switch group includes: the rear end of the fifth controlled switch is connected to the first terminal of the alternating current power supply, the rear end of the sixth controlled switch is grounded, and the front ends of the fifth controlled switch and the sixth controlled switch are commonly connected to the first terminal of the wireless charging transmitting coil;
the fourth switch group includes: the rear end of the seventh controlled switch is grounded, the rear end of the eighth controlled switch is connected to the second terminal of the alternating current power supply, and the front ends of the seventh controlled switch and the eighth controlled switch are connected to the second terminal of the wireless charging transmitting coil through a matching capacitor in common;
the fifth controlled switch, the sixth controlled switch, the seventh controlled switch and the eighth controlled switch are respectively controlled by a first control signal, a second control signal, a third control signal and a fourth control signal.
4. The wireless charging circuit of claim 2 or 3, wherein the first control signal, the second control signal, the third control signal, and the fourth control signal are square wave signals, and the corresponding controlled switch is turned on at a high level and turned off at a low level of the square wave signals;
the first control signal, the second control signal, the third control signal and the fourth control signal have the same frequency, the duty ratios of the four control signals are the same, the phases of the first control signal and the fourth control signal are the same, the phases of the second control signal and the third control signal are the same, and the high levels of the first control signal and the second control signal are staggered.
5. The wireless charging device of claim 1, wherein N-1,
the second terminal of the wireless charging transmitting coil is grounded through a matching capacitor;
the switching circuit is a half-bridge driving circuit, including: the rear ends of the ninth controlled switch and the tenth controlled switch are respectively connected to the first terminal and the second terminal of the alternating current power supply, and the front ends of the ninth controlled switch and the tenth controlled switch are commonly connected to the first terminal of the wireless charging transmitting coil;
the ninth controlled switch and the tenth controlled switch are controlled by a first control signal and a second control signal respectively.
6. The wireless charging device of claim 5, wherein the first control signal and the second control signal are square wave signals, and the corresponding controlled switch is turned on at a high level and turned off at a low level of the square wave signals;
the first control signal and the second control signal have the same frequency, the duty ratios of the first control signal and the second control signal are the same, and the high levels of the first control signal and the second control signal are staggered.
7. The wireless charging device of claim 1,
the controlled switch is a GaN semiconductor switch with breakdown voltage higher than 220V; and/or
The frequency of the control signal is between 80kHz and 150kHz, and the duty ratio is between 20% and 50%.
8. The wireless charging device of any one of claims 2, 3, and 5, further comprising:
the two input ends of the rectifying circuit are respectively connected to the first terminal and the second terminal of the alternating current power supply, and the output end of the rectifying circuit is connected to the power supply port of the control power supply and used for converting alternating current of the alternating current power supply into direct current;
and the power supply port of the control circuit is connected to the output end of the rectifying circuit, the output end of the control circuit is connected to the input end of the driving signal demodulator, and the control circuit is used for generating a driving signal for driving the driving signal demodulator, wherein the driving signal comprises the frequency and duty ratio information of the control signal.
9. The wireless charging device of claim 8, further comprising:
the current detector is used for detecting the current flowing through the wireless charging transmitting coil;
the temperature detector is used for detecting the temperature of the wireless charging transmitting coil;
a feedback circuit comprising two signal inputs: the first signal input end is electrically connected to a first terminal of the wireless charging transmitting coil to obtain a voltage signal AC 1; a second signal input end of the wireless charging transmitting coil is electrically connected to a second terminal of the wireless charging transmitting coil to obtain a voltage signal AC 2; the signal output end of the voltage signal AC1' is connected to the control circuit, and the voltage signal AC1' and the voltage signal AC2' which meet the signal input requirement of the control circuit are obtained by carrying out voltage reduction and noise reduction on the voltage signal AC1 and the voltage signal AC2 and are input to the control circuit;
the first signal input end of the control circuit is connected to the feedback circuit, the second signal input end of the control circuit is connected to the current detector, the third signal input end of the control circuit is connected to the temperature detector, and the control circuit is used for obtaining the voltage information of the wireless charging transmitting coil through the voltage signal AC1 'and the voltage signal AC2' and obtaining the current information of the wireless charging transmitting coil through the input of the current detector; the temperature information of the wireless charging transmitting coil is obtained through the input of the temperature detector, and the driving signal is adjusted according to the voltage information, the current information and the temperature information of the wireless charging transmitting coil.
10. A wireless charging method performed by the control circuit in the wireless charging device of claim 8, comprising:
step A, acquiring charging power threshold information of a charged device;
step B, under the condition of meeting the charging power threshold of the charged equipment, increasing the charging power by adopting a mode that the switching frequency gradually approaches to the resonance frequency of the wireless charging equipment;
wherein a resonant frequency of the wireless charging device
Figure FDA0003616102400000031
L is the inductance value of wireless transmitting coil that charges, C is the capacitance value of matching electric capacity.
11. The wireless charging method according to claim 10, wherein the resonance frequency of the wireless charging device is set to be between 80kHz and 100 kHz; in step B, the initial value of the switching frequency is set to be higher than 120 kHz.
12. The wireless charging method according to claim 10, wherein:
the wireless charging apparatus further includes:
the current detector is used for detecting the current flowing through the wireless charging transmitting coil;
the temperature detector is used for detecting the temperature of the wireless charging transmitting coil;
a feedback circuit comprising two signal inputs: the first signal input end is electrically connected to a first terminal of the wireless charging transmitting coil to obtain a voltage signal AC 1; a second signal input end of the wireless charging transmitting coil is electrically connected to a second terminal of the wireless charging transmitting coil to obtain a voltage signal AC 2; the signal output end of the voltage signal AC1' is connected to the control circuit, and the voltage signal AC1' and the voltage signal AC2' which meet the input requirement of the control current signal are obtained by carrying out voltage reduction and noise reduction on the voltage signal AC1 and the voltage signal AC2 and are input to the control circuit;
the first signal input end of the control circuit is connected to the feedback circuit, the second signal input end of the control circuit is connected to the current detector, and the third signal input end of the control circuit is connected to the temperature detector;
the step A comprises the following steps: obtaining information of the charging power threshold transmitted by the charged device from the voltage signal AC1 'and the voltage signal AC 2';
the step B further comprises the following steps:
step C, under the condition of meeting the charging power threshold of the charged equipment, increasing the charging power by adopting a mode of gradually increasing the duty ratio of the control signal;
step D, acquiring real-time operation information of the wireless charging equipment, including: obtaining voltage information of the wireless charging transmitting coil from a voltage signal AC1 'and a voltage signal AC 2'; obtaining current information of the charging transmitting coil from the input of the current detector; acquiring the actual charging power of the wireless charging equipment according to the voltage information and the current information of the wireless charging transmitting coil; obtaining the temperature information of the wireless charging transmitting coil through the input of the temperature detector;
step E, when one of the following conditions occurs, sending a driving signal to the driving signal demodulator to enable each controlled switch to be switched into a disconnected state:
the temperature of a wireless charging transmitting coil exceeds a preset temperature threshold;
the current of the wireless charging transmitting coil exceeds a preset current threshold value;
and thirdly, the actual charging power of the wireless charging equipment exceeds the charging power threshold of the charged equipment or fluctuates by more than 10%.
CN202210444612.4A 2021-04-29 2022-04-26 Wireless charging device and method Pending CN114899928A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202110471765 2021-04-29
CN2021104717653 2021-04-29

Publications (1)

Publication Number Publication Date
CN114899928A true CN114899928A (en) 2022-08-12

Family

ID=82719235

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210444612.4A Pending CN114899928A (en) 2021-04-29 2022-04-26 Wireless charging device and method

Country Status (1)

Country Link
CN (1) CN114899928A (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106160086A (en) * 2016-07-14 2016-11-23 邢益涛 A kind of wireless charging output device
CN106712215A (en) * 2017-02-27 2017-05-24 中惠创智（深圳）无线供电技术有限公司 Intelligent wireless charging circuit, intelligent wireless charging device and wireless charging method
CN110707945A (en) * 2018-07-10 2020-01-17 Oppo广东移动通信有限公司 Rectifier circuit, wireless charging device, power supply equipment and wireless charging system
CN111049234A (en) * 2020-01-06 2020-04-21 深圳勤基科技有限公司 Method and device for realizing constant-frequency voltage regulation wireless charging through QC and PD protocols

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106160086A (en) * 2016-07-14 2016-11-23 邢益涛 A kind of wireless charging output device
CN106712215A (en) * 2017-02-27 2017-05-24 中惠创智（深圳）无线供电技术有限公司 Intelligent wireless charging circuit, intelligent wireless charging device and wireless charging method
CN110707945A (en) * 2018-07-10 2020-01-17 Oppo广东移动通信有限公司 Rectifier circuit, wireless charging device, power supply equipment and wireless charging system
CN111049234A (en) * 2020-01-06 2020-04-21 深圳勤基科技有限公司 Method and device for realizing constant-frequency voltage regulation wireless charging through QC and PD protocols

Similar Documents

Publication Publication Date Title
US9667171B2 (en) Switching circuit, power converter, and control method
CN102332814B (en) Power factor correction control circuit for reducing EMI (electro magnetic interference)
CN203645381U (en) Vehicle charger system of electric vehicle
TWI373900B (en) High efficiency charging circuit and power supplying system
JP5556852B2 (en) Bidirectional DCDC converter
US9065327B2 (en) Efficiency optimized power converter with dual voltage power factor correction
US8488346B2 (en) Power conversion apparatus and method
CN101685980B (en) Full-bridge zero-voltage boost switching resonant converter based on LLC used for UPS
CN103280965B (en) Power factor correction control circuit capable of reducing EMI
CN103227575A (en) Three-phase soft-switched PCF rectifiers
WO2011069366A1 (en) Full voltage range llc resonant converter and control method thereof
CN104167938A (en) Pulsating current stabilizing control system
CN103973138A (en) Dynamic variable-frequency power conversion system
CN104936327A (en) Magnetron power supply power transmission and control method used for microwave oven
CN113765358A (en) Single-stage interleaved parallel AC-DC resonant conversion circuit and control method thereof
CN113206598A (en) Series resonant constant-current charging power supply
CN114899928A (en) Wireless charging device and method
WO2010139187A1 (en) Circuit for converting dc voltage to ac voltage
Jiang et al. A novel single stage single switch PFC converter with constant power control for ballast for medium HID lamps
CN203482459U (en) Improved LED driving power supply with self-regulation PFC voltage
CN217240390U (en) Aerosol generating system, aerosol generating device and wireless charging circuit
CN211531341U (en) Heating circuit
CN203801099U (en) Power circuit and microwave oven
CN103746569A (en) High-power-factor constant-voltage constant-current programmable switching power supply and power supply method
CN110582153B (en) Driving circuit, driving method thereof and electronic ballast

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination