WO2022042498A1

WO2022042498A1 - Wireless charging transmitter, wireless charging receiver, and wireless charging system

Info

Publication number: WO2022042498A1
Application number: PCT/CN2021/114137
Authority: WO
Inventors: 裴昌盛; 许兴平; 洪良
Original assignee: 华为技术有限公司
Priority date: 2020-08-26
Filing date: 2021-08-23
Publication date: 2022-03-03

Abstract

Embodiments of the present application relate to the technical field of charging. Provided are a wireless charging transmitter, a wireless charging receiver, and a wireless charging system, being used for improving the problem that a wireless charging speed is slow. The wireless charging transmitter comprises a first voltage conversion circuit, a first inverter circuit, a first transmitting coil, a second inverter circuit, and a second transmitting coil. In the wireless charging system, a first charging branch where the first transmitting coil is located has a first voltage transmission gain k1, a second charging branch where the second transmitting coil is located has a second voltage transmission gain k2, and k1 is different from k2. When only one voltage conversion circuit is provided in the wireless charging transmitter, the first output voltage V_o1 of the first charging branch is the same as the second output voltage V_o2 of the second charging branch, so that the output current separately provided by the first charging branch where the first transmitting coil is located and the second charging branch where the second transmitting coil is located for a battery can be accurately controlled.

Description

Wireless charging transmitter, wireless charging receiver and wireless charging system

This application claims the priority of the Chinese patent application with the application number 202010873200.3 and the application name "A dual-coil wireless charging system", which was submitted to the State Intellectual Property Office on August 26, 2020, and is claimed on January 2021 The priority of the Chinese patent application filed with the State Intellectual Property Office on the 12th with the application number of 202110038596.4 and the application name of "Wireless Charging Transmitter, Wireless Charging Receiver and Wireless Charging System", the entire contents of which are incorporated into this application by reference.

technical field

The present application relates to the technical field of charging, and in particular, to a wireless charging transmitter, a wireless charging receiver and a wireless charging system.

Background technique

Wireless charging technology (WCT) can use magnetic field as a conductive medium to realize wireless transmission of electric energy. The wireless charging device can have the advantages of no charging cable restraint, no plug-in interface settings, etc., which can make the user's use environment more concise and comfortable, and is conducive to the realization of a fully enclosed waterproof design of the mobile terminal. However, currently wireless charging is slower than wired charging.

SUMMARY OF THE INVENTION

The present application outputs a wireless charging transmitter, a wireless charging receiver and a wireless charging system, which are used to improve the problem of slow wireless charging speed.

To achieve the above object, the application adopts the following technical solutions:

In one aspect of the present application, a wireless charging transmitter is provided. The wireless charging transmitter is used to output alternating magnetic field to the wireless charging receiver. The wireless charging transmitter includes a first voltage conversion circuit, a first inverter circuit, a first transmission coil, a second inverter circuit and a second transmission coil. The first voltage conversion circuit is electrically connected with the adapter, and the first voltage conversion circuit is used for converting the DC power output by the adapter into DC power. The first inverter circuit is electrically connected with the first voltage conversion circuit, and the first inverter circuit is used for converting the direct current output by the first voltage conversion circuit into a first square wave signal. The first transmitting coil is electrically connected to the first inverter circuit, and the first transmitting coil is used for converting the first square wave signal into a first alternating magnetic field. The circuit in the wireless charging receiver for receiving the first alternating magnetic field, the ratio of the first output voltage V _o1 output to the battery in the wireless charging receiver and the input voltage V _in1 of the first inverter circuit is the first voltage transmission Gain k1. In addition, the second inverter circuit is electrically connected to the adapter, and the second inverter circuit is used for converting the DC power output by the adapter into a second square wave signal. The second transmitting coil is electrically connected with the second inverter circuit, and the second transmitting coil is used for converting the second square wave signal into a second alternating magnetic field. For the circuit in the wireless charging receiver for receiving the second alternating magnetic field, the ratio of the second output voltage V _o2 output to the battery to the input voltage V _in2 of the second inverter circuit is the second voltage transmission gain k2. The first voltage transmission gain k1 is different from the second voltage transmission gain k2, and the first output voltage V _o1 and the second output voltage V _o2 are the same.

In this way, on the one hand, in the above wireless charging transmitter, the first voltage conversion circuit, the first inverter circuit, and the first transmitting coil can constitute the transmitting end of the first charging branch of the wireless charging system. In addition, the second inverter circuit and the second transmitting coil can constitute the transmitting end of the second charging branch of the wireless charging system. When the above two charging branches charge the battery at the same time, compared with the wireless charging system with only one charging branch, the solution of the present application can provide more power to the battery in the same time, thereby effectively improving the battery life. Charging efficiency, so that the charging speed of wireless charging is comparable to that of wired charging. On the other hand, the wireless charging transmitter only sets the first voltage conversion circuit in the first charging branch, and the second inverter circuit in the second charging branch can be directly electrically connected to the adapter, which can effectively simplify the wireless charging transmitter Structure. On the other hand, when the battery is about to be fully charged or the coils in the first charging branch or the second charging branch generate heat, it is necessary to precisely control the output currents of the two charging branches to reduce the first charge. The current output by the branch or the second charging branch to the battery. Since the first charging branch and the second charging branch supply power to the battery after being connected in parallel, in order to prevent the output terminals of the first charging branch and the second charging branch connected in parallel from generating an inrush current, the first charging branch Or the current output by the second charging branch changes with a charging branch with a higher output voltage, the first output voltage V _o1 provided by the first charging branch to the battery and the second output voltage V provided by the second charging branch to the battery _o2 needs to be the same. In this case, in the process of adjusting the current output by the charging branch, since the voltage output by the first transmitting coil or the voltage output by the second transmitting coil may be different, the first voltage transmission gain can be set. The values of k1 and the second voltage transmission gain k2 are different, so that the first output voltage V _o1 and the second output voltage V _o2 are the same under the respective effects of the above-mentioned transmission gains. Furthermore, the output currents respectively provided by the first charging branch and the second charging branch to the battery can be precisely controlled.

Optionally, the first voltage conversion circuit is a boost circuit, and the first voltage transmission gain k1 is smaller than the second voltage transmission gain k2. In this way, since the first voltage transmission gain k1 is smaller than the second voltage transmission gain k2, the transformer formed by the first transmitting coil and the first receiving coil in the first charging branch can have a step-down effect, and can The voltage output by the first voltage conversion circuit of the boost circuit is stepped down, so that the first output voltage V _o1 and the second output voltage V _o2 are the same.

Optionally, in the wireless charging receiver, the number of turns of the first receiving coil for receiving the first alternating magnetic field is smaller than the number of turns of the first transmitting coil. At this time, the inductance of the first receiving coil is smaller than the inductance of the first transmitting coil, and the first voltage transmission gain k1 may be smaller than 1. In the wireless charging receiver, the number of turns of the second receiving coil for receiving the second alternating magnetic field is greater than or equal to the number of turns of the second transmitting coil. At this time, the inductance of the second receiving coil may be greater than or equal to the inductance of the second transmitting coil, so that the second voltage transmission gain k2 may be greater than or equal to 1.

Optionally, the first voltage conversion circuit is a step-down circuit, and the first voltage transmission gain k1 is greater than the second voltage transmission gain k2. In this way, since the first voltage transmission gain k1 is greater than the second voltage transmission gain k2, the transformer formed by the first transmitting coil and the first receiving coil in the first charging branch can have the function of boosting, and can The voltage output by the first voltage conversion circuit of the step-down circuit is boosted, so that the first output voltage V _o1 and the second output voltage V _o2 are the same.

Optionally, in the wireless charging receiver, the number of turns of the first receiving coil for receiving the first alternating magnetic field is greater than the number of turns of the first transmitting coil. At this time, the inductance of the first receiving coil is greater than the inductance of the first transmitting coil, and the first voltage transmission gain k1 may be greater than 1. In the wireless charging receiver, the number of turns of the second receiving coil for receiving the second alternating magnetic field is less than or equal to the number of turns of the second transmitting coil. At this time, the inductance of the second receiving coil may be less than or equal to the inductance of the second transmitting coil, so that the second voltage transmission gain k2 may be less than or equal to 1.

Optionally, the wireless charging transmitter further includes a first matching capacitor and a second matching capacitor. The first matching capacitor is connected in series with the first transmitting coil, and forms a first series resonance network with the first transmitting coil. In the process of charging and discharging the first matching capacitor and the first transmitting coil by the first inverter circuit, the first transmitting coil can convert the first square wave signal into the first alternating magnetic field. The second matching capacitor is connected in series with the second transmitting coil, and forms a second series resonance network with the second transmitting coil. During the process of charging and discharging the second matching capacitor and the second transmitting coil by the second inverter circuit, the second transmitting coil can convert the second square wave signal into the second alternating magnetic field. Wherein, the operating frequency of the first series resonant network is different from that of the second series resonant network.

Optionally, the wireless charging transmitter further includes a first magnetic rod. When the working frequency of the first series resonance network is lower than the working frequency of the second series resonance network, the first transmitting coil is a circular coil, and the second transmitting coil is a magnetic bar coil wound on the first magnetic bar. When the operating frequency of the first series resonant network is greater than the operating frequency of the second series resonant network, the first transmitting coil is a bar magnet coil wound on the first magnetic bar, and the second transmitting coil is a circular coil. The size of the bar magnet coil is smaller than that of the circular coil, the bar magnet coil can work at a higher operating frequency, and the bar magnet coil has a higher energy density and provides a larger charging power, which is beneficial to improve the speed of wireless charging.

Optionally, the wireless charging transmitter further includes a first transmission controller, a second transmission controller and a first wireless transceiver. The first transmission controller is electrically connected with the first voltage conversion circuit and the first inverter circuit, and the first transmission controller is used for inputting the first pulse width modulation PWM signal to the first voltage conversion circuit to control the output of the first voltage conversion circuit voltage, and is used to input the second PWM signal to the first inverter circuit to control the frequency of the first square wave signal. The second transmission controller is electrically connected to the second inverter circuit, and the second transmission controller is used for inputting a third PWM signal to the second inverter circuit to control the frequency of the second square wave signal.

Optionally, 0<|k1-k2|≤0.3. When |k1-k2|>0.3, the difference between the first voltage transfer gain k1 and the second voltage transfer gain k2 is large, and there is a large difference between the voltage of the input terminal and the voltage of the output terminal of the first voltage conversion circuit, As a result, the conversion efficiency of the first voltage conversion circuit is reduced.

Another aspect of the present application provides a wireless charging receiver. The wireless charging receiver includes a battery, a first receiving coil, a first receiving controller, a second receiving coil, and a second receiving controller. The first receiving coil is used for receiving the first alternating magnetic field output by the first transmitting coil in the wireless charging transmitter, and converting the first alternating magnetic field into alternating current. The first receiving controller is electrically connected with the first receiving coil and the battery, and is used for converting the alternating current generated by the first receiving coil into direct current and outputting the direct current to the battery. The ratio of the first output voltage V _o1 output by the first receiving controller to the battery and the input voltage V _in1 of the first inverter circuit electrically connected to the first transmitting coil in the wireless charging transmitter is the first voltage transmission gain k1. The second receiving coil is used for receiving the second alternating magnetic field output by the second transmitting coil in the wireless charging transmitter, and converting the second alternating magnetic field into alternating current. The second receiving controller is electrically connected with the second receiving coil and the battery, and is used for converting the alternating current generated by the second receiving coil into direct current, and outputting it to the battery. The ratio of the second output voltage V _o2 output by the second receiving controller to the battery and the input voltage V _in2 of the second inverter circuit electrically connected to the second transmitting coil in the wireless charging transmitter is the second voltage transmission gain k2. The first voltage transmission gain k1 is different from the second voltage transmission gain k2, and the first output voltage V _o1 and the second output voltage V _o2 are the same.

In this way, on the one hand, in the above wireless charging receiver, the first receiving coil and the first receiving controller can constitute the receiving end of the first charging branch of the wireless charging system. In addition, the second receiving coil and the second receiving controller may constitute the receiving end of the second charging branch of the wireless charging system. When the above two charging branches charge the battery at the same time, compared with the wireless charging system with only one charging branch, the solution of the present application can provide more power to the battery in the same time, thereby effectively improving the battery life. Charging efficiency, so that the charging speed of wireless charging is comparable to that of wired charging. On the other hand, when the battery is about to be fully charged or the coils in the first charging branch or the second charging branch generate heat, it is necessary to precisely control the output currents of the two charging branches to reduce the first charging The current output by the branch or the second charging branch to the battery. Since the first charging branch and the second charging branch supply power to the battery after being connected in parallel, in order to prevent the output terminals of the first charging branch and the second charging branch connected in parallel from generating an inrush current, the first charging branch Or the current output by the second charging branch changes with a charging branch with a higher output voltage, the first output voltage V _o1 provided by the first charging branch to the battery and the second output voltage V provided by the second charging branch to the battery _o2 needs to be the same. In this case, in the process of adjusting the current output by the charging branch, since the voltage output by the first transmitting coil or the voltage output by the second transmitting coil may be different, the first voltage transmission gain can be set. The values of k1 and the second voltage transfer gain k2 are different, so that the first output voltage V _o1 and the second output voltage V _o2 are the same under the respective effects of the above-mentioned transfer gains, so that the first charging branch and the second output voltage V o2 are the same. The output current provided by the charging branch to the battery is precisely controlled.

Optionally, the first voltage transmission gain k1 is smaller than the second voltage transmission gain k2. The number of turns of the first receiving coil is smaller than the number of turns of the first transmitting coil. The number of turns of the second receiving coil is greater than or equal to the number of turns of the second transmitting coil. The technical effects of setting the number of turns of the first receiving coil and the number of turns of the second receiving coil are the same as described above, and will not be repeated here.

Optionally, the first voltage transmission gain k1 is greater than the second voltage transmission gain k2. The number of turns of the first receiving coil is greater than the number of turns of the first transmitting coil. The number of turns of the second receiving coil is less than or equal to the number of turns of the second transmitting coil. The technical effects of setting the number of turns of the first receiving coil and the number of turns of the second receiving coil are the same as described above, and will not be repeated here.

Optionally, the wireless charging receiver further includes a second magnetic rod. The first receiving coil is a circular coil, and the second receiving coil is a bar magnet coil wound on the second magnet bar. Alternatively, the first receiving coil is a bar magnet coil wound on the second magnet bar, and the second receiving coil is a circular coil. The technical effect of the magnetic bar coil is the same as above, and will not be repeated here.

Optionally, the wireless charging receiver further includes a first thermistor, a second thermistor and a charging manager. The first thermistor is used for sensing the first temperature T ₁ of the first receiving coil. The second thermistor is used to sense the second temperature T ₂ of the second receiving coil. In the case where the wireless charging receiver further includes a charging manager, the charging manager may be electrically connected with the first thermistor and the second thermistor. The charge manager may be used to generate a power request based on the first temperature T ₁ and the second temperature T ₂ . The power request is used to adjust the charging power output by the wireless charging transmitter. Specifically, the charging manager may calculate the first current error and the second current error according to a preset charging strategy. The preset charging strategy includes a first mapping relationship between the first temperature T1 and the _first target current I _G1 , and a second mapping relationship between the second temperature T ₂ and the second target current I _G2 . The first receiving controller is configured to calculate the first current error and the second current error according to the preset charging strategy, including: the first receiving controller is specifically configured to obtain the first target current I _G1 according to the first temperature T ₁ and the first mapping relationship , and calculate the absolute value of the difference between the first output current I ₁ and the first target current I _G1 to obtain the first current error; the first receiving controller is also specifically used to obtain the second temperature T ₂ and the second mapping relationship according to the second The second target current I _G2 , and the absolute value of the difference between the second output current I ₂ and the second target current I _G2 is calculated to obtain the second current error. In this way, when the temperature of the receiving end coil in any one of the first charging branch and the second charging branch is relatively high, the wireless charging system can follow the above-mentioned preset charging strategy and the temperature target value of the expected temperature drop. , obtain the target current that matches the target temperature value and generate a power request, and then send the power request to the wireless charging transmitter, so that the wireless charging transmitter can adjust the output voltage of the adapter and the first voltage conversion circuit according to the above-mentioned power request , to achieve the purpose of adjusting the charging power output by the wireless charging transmitter. In addition, the switching frequency of the MOS transistors in the first inverter circuit and the second inverter circuit can also be adjusted in combination, so that the first output current I ₁ output by the first charging branch is the same as or close to the first target current I _G1 , and the first The second output current I ₂ output by the two charging branches is the same as or close to the second target current I _G2 . Therefore, the size of the first output current I ₁ and the second output current I ₂ can be allocated in a reasonable proportion, so that the temperature of the charging branch whose output current accounts for a small proportion can be lowered to the target temperature, and finally the temperature of the receiving end coil can be reduced. the goal of.

Optionally, the wireless charging receiver further includes a second voltage conversion circuit, a first isolation switch, and a second isolation switch. The second voltage conversion circuit is electrically connected to the battery, the first receiving controller and the second receiving controller, and is used for converting the voltage output by at least one of the first receiving controller and the second receiving controller into a charging voltage of the battery. When the DC voltage output by the first receiving controller is too large to be directly supplied to the battery, the second voltage conversion circuit can reduce the voltage output by the first receiving controller to a charging voltage of the battery. In addition, the first isolation switch is electrically connected to the first receiving controller and the second voltage converting circuit. The first receiving controller is used to control the opening and disconnection of the first isolation switch. The second isolation switch is electrically connected to the second receiving controller and the second voltage converting circuit. The second receiving controller is used to control the opening and disconnection of the second isolation switch. By controlling the opening and disconnection of the first isolating switch and the second isolating switch, the first charging branch and the second charging branch can work independently.

Optionally, 0<|k1-k2|≤0.3. The technical effect of this range is the same as described above, and will not be repeated here.

Another aspect of the present application provides a wireless charging system. The wireless charging system includes an adapter, any one of the above-mentioned wireless charging transmitters, and any one of the above-mentioned wireless charging receivers. The adapter is electrically connected with the first voltage conversion circuit and the second inverter circuit in the wireless charging transmitter. The technical effect of the wireless charging system is the same as the technical effect of the wireless charging transmitter and the wireless charging receiver provided in the foregoing embodiments, and will not be repeated here.

Description of drawings

FIG. 1 is a schematic structural diagram of a wireless charging system according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a circuit structure of a wireless charging system according to an embodiment of the present application;

FIG. 3 is a schematic diagram of an arrangement of the first transmitting coil, the second transmitting coil, the first receiving coil and the second receiving coil in FIG. 2;

4A is a schematic diagram of another arrangement of the first transmitting coil and the second transmitting coil in FIG. 2;

4B is a schematic diagram of another arrangement of the first receiving coil and the second receiving coil in FIG. 2;

4C is a schematic structural diagram of the first magnet bar and the magnet bar coil wound on the first magnet bar in FIG. 4A;

FIG. 4D is a schematic structural diagram of the wireless receiver shown in FIG. 4B disposed on the wireless charging transmitter shown in FIG. 4A;

FIG. 5 is a schematic diagram of a circuit structure of another wireless charging system provided by an embodiment of the present application;

6 is a schematic diagram of a circuit structure of a wireless charging system provided by the related art;

7A is a schematic diagram of a curve of an operating frequency and a voltage transmission gain of a first charging branch provided by an embodiment of the present application;

FIG. 7B is a schematic diagram of another operating frequency and voltage transmission gain of the first charging branch according to an embodiment of the present application;

8A is a schematic diagram of a curve of an operating frequency and a voltage transmission gain of a second charging branch provided by an embodiment of the present application;

FIG. 8B is a schematic diagram of another operating frequency and voltage transmission gain of the second charging branch provided by an embodiment of the present application;

FIG. 9 is a flowchart of a charging method of a wireless charging system provided by an embodiment of the present application;

FIG. 10 is a schematic diagram of a circuit structure of another wireless charging system provided by an embodiment of the present application;

Fig. 11 is a method flow chart of S102 in Fig. 9;

Fig. 12 is another method flow chart of S102 in Fig. 9;

FIG. 13 is a schematic diagram of a circuit structure of another wireless charging system provided by an embodiment of the present application;

FIG. 14 is a flowchart of a method of S104 in FIG. 9 .

Reference number:

01-wireless charging system; 10-wireless charging transmitter; 20-wireless charging receiver; 101-adapter; 102-first voltage conversion circuit; 111-first inverter circuit; 112-second inverter circuit; 121- 122-second transmitting coil; 201-first receiving controller; 202-second receiving controller; 221-first receiving coil; 222-second receiving coil; 210-second voltage conversion circuit; 200-battery; 40-circular coil; 41-first magnet bar; 50-magnet bar coil; 42-second magnet bar; 51-groove; 52-warping part; 53-magnetic structure; 31-th 1 charging branch; 32 - second charging branch; 61 - first transmitter controller; 62 - second transmitter controller; 71 - first wireless transceiver; 72 - second wireless transceiver; 73 - charging manager ; 231 - the first isolating switch; 232 - the second isolating switch; 81 - the first thermistor; 82 - the second thermistor.

detailed description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

Hereinafter, the terms "first", "second", etc. are only used for descriptive purposes, and should not be understood as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first", "second", etc., may expressly or implicitly include one or more of that feature.

In addition, in this application, directional terms such as "upper" and "lower" may include, but are not limited to, definitions relative to the schematic placement of components in the drawings. It should be understood that these directional terms may be relative concepts, They are used for relative description and clarification, which may vary accordingly depending on the orientation in which the components are placed in the drawings.

In this application, unless otherwise expressly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" may be a fixed connection, a detachable connection, or an integrated body; it may be directly connected, or Can be indirectly connected through an intermediary. In addition, the term "electrical connection" may be a direct electrical connection or an indirect electrical connection through an intermediate medium.

An embodiment of the present application provides a wireless charging system 01 . As shown in FIG. 1 , the wireless charging system 01 may include a wireless charging transmitter (transmit, TX) device 10 and a wireless charging receiver (receive, RX) device 20 . The wireless charging transmitter 10 is used for outputting an alternating magnetic field to the wireless charging receiver 20 for power transmission.

In some embodiments of the present application, the above-mentioned wireless charging receiver 20 may include a mobile phone (mobile phone), a tablet computer (pad), a computer with a wireless transceiver function, a smart wearable product (for example, a smart watch, a smart bracelet), Virtual reality (VR) terminal equipment, augmented reality (AR) terminal equipment and other equipment with wireless charging function. The above-mentioned wireless charging receiver 20 may also be wirelessly charging electric vehicles, wirelessly charging small household appliances (eg, soymilk maker, sweeping robot), drones and other electronic products. The specific form of the above-mentioned wireless charging receiver 20 is not particularly limited in this embodiment of the present application. For the convenience of description below, the description is given by taking the wireless charging receiver 20 as a mobile phone as shown in FIG. 1 as an example.

In this case, the above-mentioned wireless charging transmitter 10 may be a charging base as shown in FIG. 1 . The wireless charging transmitter 10 and the wireless charging receiver 20 may implement wireless data communication through in-band communication, for example, amplitude shift keying (ASK) modulation. Alternatively, the wireless charging transmitter 10 and the wireless charging receiver 20 can communicate with each other through out-of-band communication, such as Bluetooth (bluetooth), wireless-fidelity (WiFi), Zigbee, radio frequency identification (radio frequency identification) frequency identification, RFID), long range (Lora) wireless technology and short-range wireless communication technology (near field communication, NFC) to achieve wireless data communication.

As shown in FIG. 2 , the wireless charging transmitter 10 provided by the present application may include an adapter 101 , a first voltage conversion circuit 102 , a first inverter circuit 111 , a first transmission coil 121 , a second inverter circuit 112 and a second transmission Coil 122 . Wherein, the adapter 101 can convert 220V alternating current into direct current (eg, 5V or 20V, etc.) according to the requirement of charging power. In the embodiment of the present application, the output voltage of the adapter 101 can be adjusted within a certain voltage range (for example, 5V˜20V) as required.

In addition, the first voltage conversion circuit 102 is electrically connected to the adapter 101, and the first voltage conversion circuit 102 is used for converting the DC power output by the adapter 101 into DC power. In this case, the first voltage conversion circuit 102 may be a direct current to direct current (DC/DC) voltage converter. For example, the first voltage conversion circuit 102 may be a booster circuit, so as to boost the input DC voltage before outputting it. Alternatively, the first voltage conversion circuit 102 may be a step-down circuit, so as to step down the input DC voltage before outputting it.

The first inverter circuit 111 is electrically connected to the first voltage conversion circuit 102 . The first inverter circuit 111 is used to convert the direct current output from the first voltage conversion circuit 102 into a first square wave signal V _hb1 . For example, the first inverter circuit 111 may be a full-bridge circuit or a half-bridge circuit. The first inverter circuit 111 includes a plurality of metal oxide semiconductor (MOS) transistors. In this case, when controlling the on and off durations of the MOS transistors in the first inverter circuit 111 (ie, the switching frequency of the MOS transistors), the first square wave signal V output by the first inverter circuit 111 can be controlled The frequency and duty cycle of _hb1 . The first square wave signal V _hb1 has a plurality of switching periods T, and the switching periods T and the switching frequency F of the MOS transistor in the first inverter circuit 111 satisfy: F=1/T.

In addition, the wireless charging transmitter 10 further includes a first matching capacitor C1 connected in series with the first transmitting coil 121 . The first matching capacitor C1 and the first transmitting coil 121 may form a first series resonance network. The first transmitting coil 121 is electrically connected to the first inverter circuit 111 through the first matching capacitor C1. During the process of charging and discharging the first matching capacitor C1 and the first transmitting coil 121 by the first inverter circuit 111 , the first transmitting coil 121 can convert the first square wave signal V _hb1 into a first alternating magnetic field. In this case, the operating frequency of the first series resonant network is the same as the switching frequency F of the MOS transistor in the first inverter circuit 111 .

In addition, the second inverter circuit 112 in the wireless charging transmitter 10 is electrically connected to the above-mentioned adapter 101 , and the second inverter circuit 112 is used to convert the DC power output by the adapter 101 into a second square wave signal V _hb2 . The working principle of the second inverter circuit 112 is the same as that of the first inverter circuit 111 , and details are not repeated here. Similarly, the wireless charging transmitter 10 may further include a second matching capacitor C2 connected in series with the second transmitting coil 122 . The second matching capacitor C2 and the second transmitting coil 122 may form a second series resonance network. The second transmitting coil 122 is electrically connected to the second inverter circuit 112 through the above-mentioned second matching capacitor C2. The second transmitting coil 122 is used for converting the second square wave signal V _hb2 into a second alternating magnetic field. The operating frequency of the second series resonant network is the same as the switching frequency F of the MOS transistor in the second inverter circuit 112 .

On this basis, as shown in FIG. 2 , the wireless charging receiver 20 may include a battery 200 , a first receiving coil 221 , a second receiving coil 222 , a first receiving controller 201 , and a second receiving controller 202 . The first receiving coil 221 is used for receiving the first alternating magnetic field output by the first transmitting coil 121, and converting the first alternating magnetic field into alternating current. Similarly, the first receiving coil 221 can be connected in series with the matching capacitor C3 to form a series resonance network. The first receiving controller 201 is electrically connected to the first receiving coil 221 and the battery 200 . The first receiving controller 201 is used to convert the alternating current generated by the first receiving coil 221 into direct current, and output it to the battery 200 to charge the battery 200 .

Exemplarily, the above-mentioned first receiving controller 201 may include a rectifier. In some embodiments of the present application, when the DC voltage output by the first receiving controller 201 is too large to be directly supplied to the battery 200 , the wireless charging receiver 20 may include a second voltage converting circuit 210 . The second voltage converting circuit 210 is electrically connected to the battery 200 and the first receiving controller 201 , so that the first receiving controller 201 can be indirectly electrically connected to the battery 200 through the second voltage converting circuit 210 . The above-mentioned second voltage conversion circuit 210 is used to reduce the output voltage (eg, about 10V) of the first receiving controller 201 to a charging voltage V _bat (eg, about 4V) of the battery 200 .

For example, the second voltage conversion circuit 210 may be a DC/DC voltage converter, such as a buck (buck) circuit, or a switched capacitor (switched capacitor, SC) circuit. Among them, the input-output voltage ratio of the buck circuit can be flexibly adjusted. The input-output voltage ratio of the SC circuit is an integer, but the SC circuit can withstand a higher input-output voltage difference and has a higher voltage conversion efficiency. The present application does not limit the type of the second voltage conversion circuit 210 .

In addition, the second receiving controller 202 is electrically connected to the second receiving coil 222 , and the second voltage converting circuit 210 is also electrically connected to the second receiving controller 202 and the battery 200 . Therefore, the second receiving controller 202 may be indirectly electrically connected to the battery 200 through the second voltage converting circuit 210 . The second receiving controller 202 is configured to convert the alternating current generated by the second receiving coil 222 into direct current, and output the alternating current to the battery 200 to charge the battery 200 . Similarly, the second receiving coil 222 can be connected in series with the matching capacitor C4 to form a series resonance network. Additionally, the second receive controller 202 may include a rectifier.

The above-mentioned first transmitting coil 121 is of the same type as the first receiving coil 221 corresponding to its position, and the second transmitting coil 122 is the same type as the second receiving coil 222 corresponding to its position. Illustratively, the first transmitting coil 121 and the first receiving coil 221 may both be circular coils 40 as shown in FIG. 3 , and the second transmitting coil 122 and the second receiving coil 222 may both be circular coils as shown in FIG. 3 . shaped coil 40. In this case, a first series resonant network with a first transmitter coil 121 , a series resonance network with a first receiver coil 221 , and a second series resonance network with a second transmitter coil 122 , a second receiver coil 222 The operating frequency of the series resonant network can be below 210KHz. At this time, during the charging process of the above-mentioned wireless charging system 01, the above-mentioned circular coil 40 may adopt the wireless charging standard (Qi) protocol.

Alternatively, as another example, the first transmitting coil 121 shown in FIG. 2 may be a circular coil 40 disposed in the wireless charging transmitter 10 as shown in FIG. 4A . At this time, the first receiving coil 221 corresponding to the position of the first transmitting coil 121 may be, as shown in FIG. 4B , a circular coil 40 disposed in the wireless charging receiver 20 . In addition, as shown in FIG. 4A , the wireless charging transmitter 10 may further include a first magnetic bar 41 . At this time, the second transmitting coil 122 shown in FIG. 2 may be a bar magnet coil 50 wound on the first bar magnet 41 as shown in FIG. 4A .

For example, as shown in FIG. 4C , the first magnet bar 41 is provided with a groove 51 , and the magnet bar coil 50 can be wound at the position where the groove 51 is located. Generally, the size of the first magnet bar 41 is small, so the magnet bar coil 50 wound on the first magnet bar 41 has a shorter coil length, lower resistance and concentrated magnetic flux density than the circular coil 40 . Therefore, the magnetic bar coil 50 has a higher energy density and provides a larger charging power, which is beneficial to improve the speed of wireless charging.

In addition, as shown in FIG. 4B , the wireless charging receiver 20 may further include a second magnetic rod 42 , and the second receiving coil 222 corresponding to the position of the second transmitting coil 122 may be a magnetic rod wound on the second magnetic rod 42 . Rod coil 50 . In this way, compared with the solution in which all the coils use the above-mentioned circular coils, the present application uses the smaller-sized magnet bar coils 50 for some of the coils, which is beneficial to reduce the size of the product.

In this case, the operating frequency of the second series resonant network having the second transmitting coil 122 is different from that of the first series resonating network having the first transmitting coil 121 , and the second series resonant network adopts a smaller size magnet bar coil , so it can have a higher working frequency, for example, the working frequency of the second series resonant network can be in the range of 330Khz˜350Khz.

Or, as another example, the first transmitting coil 121 can be as shown in FIG. 4A , which is the magnetic bar coil 50 wound on the first magnetic bar 41 , and the second transmitting coil 122 can be arranged in a circle in the wireless charging transmitter 10 . shaped coil 40. At this time, the first receiving coil 221 corresponding to the position of the first transmitting coil 121 may be, as shown in FIG. 4B , the magnetic bar coil 50 wound on the second magnetic bar 42 , corresponding to the position of the second transmitting coil 122 . The second receiving coil 222 can be a circular coil 40 provided in the wireless charging receiver 20 . In this case, the operating frequency of the first series resonant network with the first transmitting coil 121 is different from that of the second series resonant network having the second transmitting coil 122, and the first series resonant network adopts a smaller size magnet bar coil , so it can have a higher working frequency, for example, the working frequency of the first series resonant network can be about 330KHz to 350KHz.

As can be seen from the above, the size of the circular coil 40 is larger than that of the magnetic rod coil 50. Therefore, as shown in FIG. 4D, when the wireless charging receiver 20 is a mobile phone, the back of the mobile phone has a large space for cloth, so the wireless charging The circular coil 40 in the charging receiver 20 is arranged on the back of the mobile phone (a side surface opposite to the display surface), and is in contact with the casing of the mobile phone. In addition, the lower part of the mobile phone has a small space for cloth parts, so the magnetic rod coil 50 in the wireless charging receiver 20 can be arranged under the mobile phone.

In this case, as shown in FIG. 4D , when the mobile phone serving as the wireless charging receiver 20 is placed on the charging base serving as the wireless charging transmitter 10 , the circular coil 40 on the wireless charging transmitter 10 is connected to the wireless charging receiver 20 . The positions of the circular coils 40 in the circuit correspond to each other, so that between the wireless charging transmitter 10 and the wireless charging receiver 20, power can be transmitted through the circular coils 40 and the circular coils 40 to form a pair of charging branches. The wireless charging receiver 20 performs charging. In addition, the positions of the magnetic rod coil 50 on the wireless charging transmitter 10 and the magnetic rod coil 50 in the wireless charging receiver 20 correspond to each other, so that the wireless charging transmitter 10 and the wireless charging receiver 20 can pass through the magnetic rod. The coil 50 and the magnetic bar coil 50 perform power transmission to form another charging branch to charge the wireless charging receiver 20 .

In some embodiments of the present application, in order to make the position of the magnetic rod coil 50 on the wireless charging transmitter 10 and the magnetic rod coil 50 in the wireless charging receiver 20 to be accurate, the wireless charging transmitter 10 and the wireless charging Magnetic attraction structures 53 as shown in FIG. 4B may be respectively provided in the receivers 20 . For example, the magnetic attraction structure 53 may be a magnetic bar structure made of magnetic materials. Alternatively, in other embodiments of the present application, some structures for assisting positioning may also be provided in the wireless charging transmitter 10 . For example, the portion of the wireless charging transmitter 10 for carrying the wireless charging receiver 20 may be warped upward to form a warped portion 52 as shown in FIG. 4B . The warped portion 52 can limit the position of the wireless charging receiver 20 to prevent the wireless charging receiver 20 from sliding down, which would cause the magnetic rod coil 50 on the wireless charging transmitter 10 and the magnetic rod coil 50 in the wireless charging receiver 20 to fail. Accurate alignment.

It can be seen from the above that there are two charging branches between the wireless charging transmitter 10 and the wireless charging receiver 20, and the above two charging branches are described below. Specifically, in the wireless charging system 01 composed of the above-mentioned wireless charging transmitter 10 and wireless charging receiver 20, as shown in FIG. 5, the first voltage conversion circuit 102, the first inverter circuit 111, the first transmitting coil 121, The first receiving coil 221 and the first receiving controller 201 may constitute the first charging branch 31 of the wireless charging system 01 . In addition, the second inverter circuit 112 , the second transmitting coil 122 , the second receiving coil 222 and the second receiving controller 202 may constitute the second charging branch 32 of the wireless charging system 01 .

In this way, the wireless charging system 01 provided in this embodiment of the present application may have the above two charging branches (the first charging branch 31 and the second charging branch 32 ). During charging, compared with the wireless charging system 01 having only one charging branch, the solution of the present application provides more power to the battery 200 in the same time, so that the charging efficiency of the battery 200 can be effectively improved, and the charging efficiency of the wireless charging can be improved. Speeds are comparable to those of wired charging.

In order to enable the first charging branch 31 and the second charging branch 32 to supply power to the battery 200 at the same time, the first receiving controller 201 in the first charging branch 31 and the second receiving controller 201 in the second charging branch 32 The device 202 can be connected in parallel to supply power to the battery 200 . Since the two voltage sources cannot be directly connected in parallel, at least one of the first receiving controller 201 and the second receiving controller 202 can be equivalent to a current source. In this case, the battery 200 is charged with a total current formed by combining the currents output by the first receiving controller 201 and the second receiving controller 202 in parallel. For example, when the first charging branch 31 and the second charging branch 32 charge the battery 200 at the same time, the charging current _I3 received by the battery 200 is the first output current I output by the first receiving controller 201 ₁ and the sum of the second output current I ₂ output by the second receiving controller 202 , that is, I ₃ =I ₁ +I ₂ .

Based on this, in the process of charging the battery 200 by the first charging branch 31 and the second charging branch 32 , the magnitude of the current output by each charging branch needs to be flexibly and accurately adjusted according to the needs of the user. For example, when the battery 200 is about to be fully charged, it is necessary to precisely control the output currents of the above two charging branches, so as to reduce the current output by the first charging branch 31 and the second charging branch 32 to the battery 200, so that the battery When the 200 is about to be fully charged, the charging power supplied to the battery 200 can be reduced. Or in order to avoid the heating of the charging coils in each charging branch, which will affect the product performance, it is necessary to reduce the output current (the first output current I ₁ or the second output current I ₂ ) of the charging branch where the heating phenomenon occurs, so as to achieve The temperature of the charging branch is reduced, and the temperature of the charging branch is limited.

In this case, since the first receiving controller 201 and the second receiving controller 202 supply power to the battery 200 in parallel, in order to avoid the parallel connection of the output terminals of the first charging branch 31 and the second charging branch 32 The inrush current causes the current output by the first charging branch 31 and the second charging branch 32 to change with the charging branch with a higher output voltage. Thus, precise control of the magnitudes of the first output current I ₁ and the second output current I ₂ is achieved, and the first output voltage V o1 output by the first receiving controller 201 and the second output voltage V _o1 output by the second receiving controller 202 are The voltage V _o2 is the same.

It should be noted that the first output voltage V _o1 output by the first receiving controller 201 is the same as the second output voltage V _o2 output by the second receiving controller 202 , which means that the first charging branch 31 and the first charging branch 31 connected in parallel On the premise that the output terminals of the two charging branches 32 do not generate inrush current, the first output voltage V _o1 and the second output voltage V _o2 are the same or approximately the same.

On this basis, when the first output current I ₁ output by the first charging branch 31 or the second output current I ₂ output by the second charging branch 32 needs to be adjusted, the The voltage output by the first transmitting coil 121 at the transmitting end, or the voltage output by the second transmitting coil 122 at the transmitting end serving as the second charging branch 32 is adjusted to satisfy the output of the first charging branch 31 the first output current I ₁ or the first The second output current I ₂ output by the two charging branches 32 is required.

In addition, in the embodiment of the present application, as shown in FIG. 5 , the wireless charging transmitter 10 may only set the first voltage conversion circuit 102 in the first charging branch 31 , and the second inverse circuit 102 in the second charging branch 32 The transformer circuit 112 can be directly electrically connected to the adapter 101 . In this way, in contrast to the wireless charging system 01 shown in FIG. 6 , the DC/DC voltage converter is provided before the inverter circuit in both the first charging branch 31 and the second charging branch 32 . , the present application can effectively simplify the structure of the wireless charging transmitter 10 .

Based on this, as shown in FIG. 5 , in the process of adjusting the voltage output by the first transmitting coil 121 or the voltage output by the second transmitting coil 122 , the input voltage V _in1 of the first inverter circuit 111 is the same as the second inverse voltage V in1 There may be a difference between the input voltages V _in2 of the inverter circuit 112 . At this time, in order to make the first output voltage V _o1 output by the first receiving controller 201 and the second output voltage V _o2 output by the second receiving controller 202 to be the same, the first voltage transmission of the first charging branch 31 is required The gain k1 may be different from the second voltage transfer gain k2 of the second charging branch 32 .

Illustratively, 0<|k1-k2|≤0.3. When |k1-k2|>0.3, the difference between the first voltage transfer gain k1 and the second voltage transfer gain k2 is large, and the voltage at the input end and the voltage at the output end of the first voltage conversion circuit 102 are both greatly different. , causing the conversion efficiency of the first voltage conversion circuit 102 to decrease. For example, |k1-k2| may be 0.1, 0.2 or 0.3.

Wherein, in the first charging branch 31, the ratio of the first output voltage V _o1 output by the first receiving controller 201 to the battery 200 to the input voltage V _in1 of the first inverter circuit 111 is the first charging branch The first voltage transfer gain k1 of 31. That is, k1=V _o1 /V _in1 . In addition, in the second charging branch 32 , the ratio of the second output voltage V _o2 output by the second receiving controller 202 to the battery 200 to the input voltage V _in2 of the second inverter circuit 112 is the second charging branch 32 The second voltage transfer gain k2. That is, k2=V _o2 /V _in2 .

The following describes the setting process of the first voltage transmission gain k1 of the first charging branch 31 and the second voltage transmission gain k2 of the second charging branch 32 with reference to the circuit structure shown in FIG. The control processes of the charging transmitter 10 and the wireless charging receiver 20 are illustrated in detail.

Example 1

In this example, the first transmitting coil 121 and the first receiving coil 221 in the first charging branch 31 are the above-mentioned circular coils 40 (as shown in FIG. 4D ), and the second transmitting coil 122 in the second charging branch 32 And the second receiving coil 222 is the above-mentioned bar magnet coil 50 (shown in FIG. 4D ). In this case, the operating frequency of the second transmitting coil 122 and the second receiving coil 222 in the second charging branch 32 (for example, in the range of 330KHz˜350KHz) is higher than that of the first transmitting coil in the first charging branch 31 . 121 and the operating frequency of the first receiving coil 221 (for example, below 210KHz).

In addition, in this example, the first voltage conversion circuit 102 in FIG. 5 may be a boost circuit, and the first voltage transmission gain k1 of the first charging branch 31 is smaller than the second voltage transmission gain of the second charging branch 32 Gain k2, ie k1<k2. In this case, the number of turns Nb1 of the first receiving coil 221 may be smaller than the number of turns Na1 of the first transmitting coil 121 , that is, Nb1 < Na1 . At this time, the ratio of the output voltage to the input voltage of the transformer formed by the first transmitting coil 121 as the circular coil and the first receiving coil 221 is less than 1, so that k1<1. In addition, the number of turns Nb2 of the second receiving coil 222 is greater than or equal to the number of turns Na2 of the second transmitting coil 122, that is, Nb2≧Na2. At this time, the second transmitting coil 122 and the second receiving coil 222 as the magnet coil are formed, and the ratio of the output voltage of the transformer to the input voltage is greater than or equal to 1, so that k2≥1.

In the following, the first voltage transmission gain k1 of the first charging branch 31 can satisfy k1<1, and in order to make the first output current _I1 output by the first charging branch 31 meet the requirement, the The adjustment method of the output voltage of the first transmitting coil 121 at the transmitting end will be described.

It can be seen from the above that the sizes of the first transmitting coil 121 and the first receiving coil 221 as the circular coil 40 (as shown in FIG. 4D ) are relatively large, therefore, the allowable positions of the first transmitting coil 121 and the first receiving coil 221 The degree of offset is relatively large (for example, the allowable center offset of the transmitting coil and the receiving coil can be about ±10mm). Therefore, the variation range of the coupling coefficient between the first transmitting coil 121 and the first receiving coil 221 is relatively large, for example, the coupling coefficient may be set between 0.5 and 0.75.

It should be noted that the coupling coefficient between the transmitting coil and the receiving coil refers to the tightness of the coupling between the transmitting coil and the receiving coil. The coupling coefficient is related to the position offset degree of the two coils. When the offset degree of the transmitting coil and the receiving coil is small, the coupling coefficient is higher, and vice versa. When the coupling coefficient of the transmitting coil and the receiving coil is higher, the efficiency of transmitting power of the transmitting coil and the receiving coil is higher.

For example, when the output current provided by the charging branch to the battery 200 is different, in the wireless charging system 01, the load impedance of the wireless receiver 20 is different. When the coupling coefficient between the first transmitting coil 121 and the first receiving coil 221 is 0.75, and the load impedance of the wireless charging receiver 20 is different, the operating frequency of the first series resonant network where the first transmitting coil 121 is located is the same as The relationship curve of the first voltage transfer gain k1 of the first charging branch 31 is shown in FIG. 7A . 7A, the load impedance corresponding to curve ① is 2.5Ω, the load impedance corresponding to curve ② is 5Ω, and the load impedance corresponding to curve ③ is 10Ω. It can be seen that when the operating frequency of curve ①, curve ② and curve ③ is around 1.5×10 ⁵ KHz, the first voltage transmission gain k1 of the first charging branch 31 is the same, and at this time k1 is around 0.8.

In addition, when the coupling coefficient between the first transmitting coil 121 and the first receiving coil 221 is 0.5, and the load impedance of the wireless charging receiver 20 is different, the operation of the first series resonant network where the first transmitting coil 121 is located will not work. The relationship between the frequency and the first voltage transfer gain k1 of the first charging branch 31 is shown in FIG. 7B . 7B, the load impedance corresponding to curve ① is 2.5Ω, the load impedance corresponding to curve ② is 5Ω, and the load impedance corresponding to curve ③ is 10Ω. It can be seen that when the operating frequency of curve ①, curve ② and curve ③ is around 1.0×10 ⁵ KHz, the first voltage transmission gain k1 of the first charging branch 31 is the same, and at this time k1 is around 0.9.

In this case, as can be seen from FIGS. 7A and 7B , when the coupling coefficient between the first transmitting coil 121 and the first receiving coil 221 varies within the range of 0.5 to 0.75, when the first charging branch When the first voltage transmission gain k1 of 31 is in the range of 0.8 to 0.9, the change of the load impedance of the wireless charging receiver 20 will not affect the first voltage transmission gain k1 of the first charging branch 31 and the first transmitting coil 121 The operating frequency of the first series resonant network in which it is located has an effect.

Therefore, when the output current provided by the charging branch to the battery 200 is different, in order to satisfy the change of the load impedance of the wireless charging receiver 20, the first voltage transmission gain k1 of the first charging branch 31 can be selected as 0.8 or 0.9, so that the A voltage transfer gain k1 can satisfy k<1. For example, the number of turns of the first receiving coil 221 can be made smaller than the number of turns of the first transmitting coil 121, and the inductance of the first receiving coil 221 is smaller than the inductance of the first transmitting coil 121, so that the first voltage transmission gain k1 is smaller than 1.

In addition, it can be seen from the above that when k1 is 0.8 or 0.9, the frequency offset is 50KHz (from 1.5×10 ⁵ KHz to 1.0×10 ⁵ KHz), and the frequency offset is large. Therefore, in this example, the first series resonant network where the first transmitting coil 121 is located is not suitable for a fixed operating frequency.

Based on this, in order to make the first output current I ₁ output by the first charging branch 31 meet the requirements, in the process of adjusting the output voltage of the first transmitting coil 121 serving as the transmitting end of the first charging branch 31, the wireless charging receiving The SCP (Secure copy, based on SSH) communication protocol can be used between the transmitter 20 and the wireless charging transmitter 10 to adjust the voltage output by the adapter 101 . In addition, the operating frequency of the first series resonance network where the first transmitting coil 121 is located (ie the switching frequency F of the MOS transistor in the first inverter circuit 111 ) and the output voltage of the first voltage conversion circuit 102 can also be adjusted.

In the following, the second voltage transmission gain k2 of the second charging branch 32 can satisfy k2≥1, and in order to make the second output current _I2 output by the second charging branch 32 meet the requirements, the The adjustment method of the output voltage of the second transmitting coil 122 at the transmitting end will be described.

It can be seen from the above that the sizes of the second transmitting coil 122 and the second receiving coil 222 as the magnet bar coil 50 (as shown in FIG. 4D ) are relatively small, and when the magnetic attraction structure 53 (as shown in FIG. 4D ) is used to assist positioning , the offset degree of the second transmitting coil 122 and the second receiving coil 222 is small. Therefore, the variation range of the coupling coefficient between the second transmitting coil 122 and the second receiving coil 222 is narrow, for example, the coupling coefficient may be set between 0.55 and 0.6.

For example, when the coupling coefficient between the second transmitting coil 122 and the second receiving coil 222 is 0.55, when the load impedance of the wireless charging receiver 20 is different, the second series resonant network where the second transmitting coil 122 is located will The relationship between the operating frequency and the second voltage transfer gain k2 of the second charging branch 32 is shown in FIG. 8A . 8A , the load impedance corresponding to curve ① is 2.5Ω, the load impedance corresponding to curve ② is 5Ω, and the load impedance corresponding to curve ③ is 10Ω. It can be seen that when the operating frequency of curve ①, curve ② and curve ③ is around 3.4×10 ⁵ KHz, the second voltage transmission gain k2 of the second charging branch 32 is the same, and k2 is located around 1 at this time.

In addition, when the coupling coefficient between the second transmitting coil 122 and the second receiving coil 222 is 0.6, when the load impedance of the wireless charging receiver 20 is different, the operation of the second series resonant network where the second transmitting coil 122 is located will not work. The relationship between the frequency and the second voltage transfer gain k2 of the second charging branch 32 is shown in FIG. 8B . 8B, the load impedance corresponding to curve ① is 2.5Ω, the load impedance corresponding to curve ② is 5Ω, and the load impedance corresponding to curve ③ is 10Ω. It can be seen that when the operating frequency of curve ①, curve ② and curve ③ is around 3.6×10 ⁵ KHz, the second voltage transmission gain k2 of the second charging branch 32 is the same, and k2 is located around 1 at this time.

In this case, as can be seen from FIG. 8A and FIG. 8B , when the coupling coefficient between the second transmitting coil 122 and the second receiving coil 222 varies in the range of 0.55˜0.6, when the second charging branch When the second voltage transmission gain k2 of 32 is near 1, the change of the load impedance of the wireless charging receiver 20 will not affect the second voltage transmission gain k2 of the second charging branch 32 and the second voltage transmission gain k2 of the second transmitting coil 122. The operating frequency used by the series resonant network has an effect.

Therefore, when the output current provided by the charging branch to the battery 200 is different, in order to satisfy the change of the load impedance of the wireless charging receiver 20 , the second voltage transmission gain k2 of the second charging branch 32 can be selected to be around 1. For example, the number of turns of the second receiving coil 222 may be equal to the number of turns of the second transmitting coil 122, and at this time k2=1. In addition, considering the line impedance in the wireless charging receiver 20, k2 may be slightly larger than 1, for example, k2=1.05, so that the second voltage transmission gain k2 of the second charging branch 32 can satisfy k2>1. For example, the number of turns of the second receiving coil 222 may be slightly larger than the number of turns of the second transmitting coil 122, and the inductance of the second receiving coil 222 is slightly larger than the inductance of the second transmitting coil 122, so that the second voltage transmission gain k2 is slightly larger than 1.

In addition, it can be seen from the above that when k2=1.05, the frequency offset is 20KHz (offset from 3.6×10 ⁵ KHz to 3.4×10 ⁵ KHz), and the frequency offset is small. Therefore, in this example, the second series resonant network where the second transmitting coil 122 is located is suitable to use a fixed operating frequency. Moreover, after the coupling coefficient between the second transmitting coil 122 and the second receiving coil 222 is determined, it can be seen from FIG. 8A or FIG. 8B that the gain curve of the second charging branch 32 is relatively steep, and when the operating frequency changes , the voltage transfer gain will change greatly. Therefore, in order to meet the demand of the second output current _I2 output by the second charging branch 32, in the process of adjusting the voltage output by the second transmitting coil 122, simply by changing the operating frequency of the second series resonant network, it is very difficult to It is difficult to obtain higher current control accuracy. In addition, since the operating frequency of the second charging branch 32 is relatively high, for example, within the range of 330KHz to 650KHz, when the operating frequency is increased to the accuracy, the digital control accuracy of the wireless charging transmitter 10 is required to be too high, which is not conducive to reducing the cost and product reliability. Therefore, the second series resonant network adopts a fixed operating frequency, that is, the switching frequency F of the MOS transistor in the second inverter circuit 112 adopts a fixed frequency.

Based on this, in order to meet the requirement of the second output current I ₂ output by the second charging branch 32 , in the process of adjusting the output voltage of the second transmitting coil 122 serving as the transmitting end of the second charging branch 32 , the wireless charging receiving The voltage output by the adapter 101 can be adjusted between the transmitter 20 and the wireless charging transmitter 10 through the SCP communication protocol.

To sum up, in this example, the first voltage transfer gain k1 of the first charging branch 31 satisfies k1<1, for example, k1 is 0.8 or 0.9, and the second voltage transfer gain k2 of the second charging branch 32 satisfies k2≥ 1, for example, k2 is 1.05. In this way, as shown in FIG. 5 , in the case where the first receiving controller 201 and the second receiving controller 202 are connected in parallel, in order to be able to adjust the magnitude of the first output current _I1 and the second output current _I2 as required Precise control is performed to prevent the current output by the first receiving controller 201 and the second receiving controller 202 from changing with a charging branch with a higher output voltage, so that the first output voltage V _o1 output by the first receiving controller 201 , which may be the same as the second output voltage V _o2 output by the second receiving controller 202 .

It can be seen from the above that the wireless charging system 01 includes the first charging branch 31 and the second charging branch 32 as shown in FIG. 5 . In this case, according to the heating condition of the coil and the support of the charging base, the above wireless charging The workflow of the system 01 may be as shown in FIG. 9 , including S101 to S107 .

S101. Start.

The wireless charging receiver 20 as a mobile phone is placed on the wireless charging transmitter 10 as a charging base, and the wireless charging system 01 constituted by the wireless charging transmitter 10 and the wireless charging receiver 20 executes the above S101, so that the wireless charging transmitter 10 and A communication connection is established between the wireless charging receivers 20 through the above-mentioned in-band or out-of-band communication method.

For example, when a communication connection is established between the wireless charging transmitter 10 and the wireless charging receiver 20 in an out-of-band communication manner, as shown in FIG. 10 , the wireless charging transmitter 10 includes a first wireless transceiver 71, and the wireless charging receiver The transceiver 20 includes a second wireless transceiver 72 . The wireless communication between the first wireless transceiver 71 and the second wireless transceiver 72 may be performed in an out-of-band communication manner. For example, the above-mentioned first wireless transceiver 71 and second wireless transceiver 72 may be a Bluetooth controller.

In some embodiments of the present application, when the wireless charging receiver 20 serving as a mobile phone is placed on the wireless charging transmitter 10 serving as a charging base, and the first transmitting coil 121 and the wireless charging receiver 20 in the wireless charging transmitter 10 The positions of the first receiving coils 221 are aligned, the first transmitting coils 121 are in the in-position state, and the first charging branch 31 where the first transmitting coils 121 and the first receiving coils 221 are located can work. In addition, the positions of the second transmitting coil 122 in the wireless charging transmitter 10 and the second receiving coil 222 in the wireless charging receiver 20 are aligned, the second transmitting coil 122 is in the in-position state, the second transmitting coil 122 and the second The second charging branch 32 where the receiving coil 222 is located can work. In this case, when the first charging branch 31 and the second charging branch 32 can work at the same time, the wireless charging system 01 executes S102 and S103 in FIG. 9 .

S102, the first charging branch 31 and the second charging branch 32 work simultaneously. In this case, the wireless charging system 01 executes the method of S102, which may specifically include S201 to S204 as shown in FIG. 11 .

S201 , sending the first in-position command of the first transmitting coil 121 and the second in-position command of the second transmitting coil 122 .

The wireless charging transmitter 10 may perform the above-mentioned S201. Specifically, the first transmission controller 61 in the wireless charging transmitter 10 shown in FIG. 10 may send the above-mentioned first in-position instruction to the first wireless transceiver 71 . The first in-position instruction is used to indicate that the center offset between the first receiving coil 221 in the wireless charging receiver 20 and the above-mentioned first transmitting coil 121 satisfies the offset allowed for normal charging, for example, about ±10mm. At this time, the wireless charging transmitter 10 serving as the charging base supports the use of the first charging branch 31 to charge the battery 200 .

In addition, the second transmission controller 62 in the wireless charging transmitter 10 shown in FIG. 10 may send the above-mentioned second in-position instruction to the first wireless transceiver 71 . The second in-position instruction is used to indicate that the offset between the second receiving coil 222 in the wireless charging receiver 20 and the above-mentioned second transmitting coil 122 satisfies the offset allowed by normal charging. It can be seen from the above that the second transmitting coil 122 and the second receiving coil 222 are the magnetic bar coils 50 (as shown in FIG. 4D ), which are small in size and play a role in the auxiliary positioning of the magnetic attraction structure 53 (as shown in FIG. 4D ). In this case, the degree of offset between the second transmitting coil 122 and the second receiving coil 222 is small, and the alignment accuracy is high. At this time, the wireless charging transmitter 10 serving as the charging base supports the use of the second charging branch 32 to charge the battery 200 . Next, the first wireless transceiver 71 in the wireless charging transmitter 10 receives the first in-position command and the second in-position command, and sends them to the wireless charging receiver 20 .

S202. Send a first power request.

In order to perform the above S202, the wireless charging receiver 20 may include a charging manager (charger) 73 as shown in FIG. 10 . The charge manager 73 may be electrically connected to the battery 200 and the second wireless transceiver 72 . In the case where the wireless charging receiver 20 includes a system on chip (SoC), the above-mentioned charging manager 73 may be integrated in the SoC, or be provided independently of the SoC and electrically connected with the SoC.

When the battery 200 can perform high-power fast charging, the charging manager 73 can generate a first power request during the process of the wireless charging receiver 20 performing the above S202, and send the wireless charging transmitter 10 to the wireless charging transmitter 10 through the second wireless transceiver 72. The first power request is sent. The first power request is used to indicate that the charging power provided by the wireless charging transmitter 10 to the battery 200 is the maximum charging power P _max of the battery 200 .

For example, the conditions for fast charging the battery 200 with high power may include: the power of the battery 200 is lower than a preset power, and the preset power is close to and less than the full power. Alternatively, the temperature of the battery 200 is in a normal temperature state. A fuel gauge and a thermistor can be set inside the charging manager 73 to collect the power and temperature of the battery 200 respectively. In addition, the conditions for the high-power fast charging of the battery 200 may be that the temperature of the first receiving coil 221 and the temperature of the second receiving coil 222 are in a normal temperature state.

S203. Generate a first charging power P1 and a second charging power P2 according to the first power request.

Specifically, in the process of performing the above S203 on the wireless charging transmitter 10, the first transmission controller 61 shown in FIG. 10 can receive the above-mentioned first power request through the first wireless transmitter 71, and according to the first power request A first pulse width modulation (PWM) signal is input to the first voltage conversion circuit 102 . By controlling the duty cycle of the first PWM signal, the magnitude of the output voltage of the first voltage conversion circuit 102 can be controlled. When the first voltage conversion circuit 102 is a boost circuit, the duty cycle of the first PWM signal may be inversely proportional to the output voltage of the first voltage conversion circuit 102 . Therefore, the duty cycle of the first PWM signal can be reduced to increase the output voltage of the first voltage conversion circuit 102 to realize high-power charging. In addition, when the first voltage conversion circuit 102 is a buck circuit, the duty cycle of the first PWM signal may be proportional to the output voltage of the first voltage conversion circuit 102 .

It can be seen from the above that when the first transmitting coil 121 and the first receiving coil 221 are circular coils, and the first voltage transmission gain k1 of the first charging branch 31 can be selected as 0.8 or 0.9, the first charging branch The frequency offset of 31 is 50KHz, and the frequency offset is larger. Therefore, the first transmitting coil 121 does not need to work at a fixed frequency. Therefore, the operating frequency of the first transmitting coil 121 can be adjusted to achieve the purpose of increasing the output power.

In this case, the first transmit controller 61 may also input a second PWM signal to the first inverter circuit 111 according to the first power request, and control the frequency of the second PWM signal to control the output of the first inverter circuit 111. The frequency of the square wave signal V _hb1 enables the first inverter circuit 111 to output the first charging power P1 . The frequency of the second PWM signal is inversely proportional to the output current of the first inverter circuit 111 . Therefore, the frequency of the second PWM signal can be reduced, and the output current of the first inverter circuit 111 can be increased, so as to realize high-power charging.

In addition, it can be seen from the above that when the second transmitting coil 122 and the second receiving coil 222 are magnetic rod coils, and the second voltage transmission gain k2 of the second charging branch 32 can be selected as 1.05, the second charging branch The frequency offset of 32 is 20KHz, and the frequency offset is small. Therefore, the first transmitting coil 121 is suitable for working at a fixed frequency. Therefore, the second transmission controller 62 can input the third PWM signal with a fixed frequency to the second inverter circuit 112, so that the first inverter circuit 111 can output the second charging power P2.

In other embodiments of the present application, in order to implement high-power charging, the wireless charging receiver 20 and the adapter 101 may send the first power request generated by the charging manager 73 to the adapter 101 through the SCP communication protocol, so that the The adapter 101 can increase the output voltage according to the first power request, so that the voltages received by the first voltage conversion circuit 102 and the second inverter circuit 112 are both increased, so that the wireless charging transmitter 10 can output the above-mentioned first voltage. A charging power P1 and a second charging power P2 are used to charge the battery with high power.

S204: Transmit the first charging power P1 and the second charging power P2.

When the wireless charging transmitter 10 performs the process of S204, the first transmitting coil 121 may transmit the first charging power P1 to the first receiving coil 211 by transmitting the first alternating magnetic field. The second transmitting coil 122 may transmit the second charging power P2 to the second receiving coil 222 by transmitting the second alternating magnetic field.

S103. Charge the battery 200 with the third charging power P3. Wherein, P3=P1+P2; P3=P _max .

During the process of the wireless charging receiver 20 performing the above S205, the first receiving controller 201 can convert the alternating current output by the first receiving coil 221 into direct current, and output the first output voltage V _o1 and the first output current I to the battery 200 ₁ to charge the battery 200 with the first charging power P1 (P1=V _o1 ×I ₁ ). The first receiving controller 202 can convert the alternating current output from the second receiving coil 222 into direct current, and output the second output voltage V _o2 and the second output current I ₂ to the battery 200 to use the second charging power P2 (P1=V _o2 ×I ₂ ) to charge the battery 200 . At this time, the total current I ₃ provided by the first charging branch 31 and the second charging branch 32 to the battery 200 is the sum of the first output current I ₁ and the second output current I. By reasonably proportioning the magnitudes of the first output current I ₁ and the second output current I ₂ , for example, P1=0.3×P _max , P2=0.7×P _max , the wireless charging transmitter 10 can provide the battery 200 with The charging power is the maximum charging power P _max of the battery 200 .

The above description is given by taking the charging power provided by the wireless charging transmitter 10 to the battery 200 as the maximum charging power P _max of the battery 200 , and taking the high-power fast charging of the battery 200 as an example. In other embodiments of the present application, when the conditions for high-power fast charging of the battery 200 are not met, the wireless charging system 01 executes the method of S102, which may specifically include S301 to S304 as shown in FIG. 12 .

S301 , sending the first in-position command of the first transmitting coil 121 and the second in-position command of the second transmitting coil 122 . S301 is the same as the above-mentioned S201, and will not be described in detail here.

S302. Send a second power request.

When the above-mentioned conditions for high-power fast charging of the battery 200 are not satisfied, for example, when the temperature of the first receiving coil 221 and the temperature of the second receiving coil 222 are too high, the wireless charging receiver 20 performs the process of S202 above. The charging manager 73 may generate a second power request and transmit the second power request to the wireless charging transmitter 10 via the second wireless transceiver 72 . The second power request is used to instruct the wireless charging transmitter 10 to charge the battery 200 with low power. Therefore, the charging power provided by the wireless charging transmitter 10 to the battery 200 is less than the above-mentioned maximum charging power P _max .

In some embodiments of the present application, in order to detect the temperature of the first receiving coil 221 and the temperature of the second receiving coil 222, as shown in FIG. The first thermistor 81 in the vicinity and the second thermistor 82 disposed in the vicinity of the second receiving coil 222 . When the first receiving controller 201 is internally integrated with a microcontroller unit (MCU), the first thermistor 81 and the second thermistor 82 can both be electrically connected to the MCU in the first receiving controller 201 . Alternatively, both the first thermistor 81 and the second thermistor 82 may be electrically connected to the above-mentioned charging manager 73 . For the convenience of description below, the description is given by taking an example that both the first thermistor 81 and the second thermistor 82 are electrically connected to the MCU in the first receiving controller 201 .

In this case, before the wireless charging receiver 20 performs the above-mentioned S202, the first thermistor 81 senses the first temperature T ₁ of the first receiving coil 221 and sends the first temperature T ₁ to the first receiving control device 201. In addition, the second thermistor 82 senses the second temperature T ₂ of the second receiving coil 222 and transmits the second temperature T ₂ to the first receiving controller 201 . The first receiving controller 201 can also be electrically connected to the charging manager 73, and the first receiving controller 201 can compare the temperature sensed by the first thermistor 81 and the second thermistor 82, and when the temperature exceeds the preset value When the temperature is high, a control command is sent to the charging manager 73, so that the charging manager 73 can generate the above-mentioned second power request.

Illustratively, in order to perform closed-loop control on the first output current I ₁ output by the first receiving controller 201 and the second output current I ₂ output by the second receiving controller 202, the MCU integrated in the first receiving controller 201 The first current error ΔI ₁ and the second current error ΔI ₂ can be calculated. The first current error ΔI _{1 is the absolute value of the difference between the first output current I 1} _output by the first receiving controller 201 to the battery 200 and the first target current I _G1 , that is, ΔI ₁ =|I ₁ -I _G1 |. The second current error ΔI _{2 is the absolute value of the difference between the second output current I 2} _and the second target current I _G2 , that is, ΔI ₂ =|I ₂ −I _G2 |.

For example, the first receiving controller 201 may calculate the first current error ΔI ₁ and the second current error ΔI ₂ according to a preset charging strategy. For example, the above-mentioned preset charging strategy may include a first mapping relationship between the first temperature T1 and the _first target current I _G1 , and a second mapping relationship between the second temperature T ₂ and the second target current I _G2 . For example, the first mapping relationship includes multiple first temperatures T ₁ and multiple first target currents I _G1 , and the value of each first temperature T ₁ matches the value of one first target current I _G1 . Similarly, the second mapping relationship includes multiple second temperatures T ₂ and multiple second target currents I _G2 , and the value of each second temperature T ₂ matches the value of one second target current I _G2 .

In this case, the first receiving controller 201 can obtain the first target current I _G1 matching the value of the first temperature T ₁ according to the first temperature T ₁ and the first mapping relationship, and calculate the first output The absolute value of the difference between the current I ₁ and the first target current I _G1 |I ₁ -I _G1 |, the first current error ΔI ₁ (ΔI ₁ =|I ₁ -I _G1 |) is obtained. In addition, the first receiving controller 201 obtains a second target current I _G2 matching the value of the second temperature T ₂ according to the second temperature T ₂ and the second mapping relationship, and calculates the second output current I ₂ and the The absolute value of the difference between the second target currents I _G2 |I ₂ -I _G2 |, the second current error ΔI ₂ (ΔI ₂ =|I ₂ -I _G2 |) is obtained.

It should be noted that the above description is based on an example of calculating the first current error ΔI ₁ and the second current error ΔI ₂ by the first receiving controller 201 when an MCU is integrated in the first receiving controller 201 . In other embodiments of the present application, when the above-mentioned MCU is integrated into the second receiving controller 202, the second wireless transceiver 72 can calculate the above-mentioned first current error ΔI ₁ and second current error ΔI ₂ . Alternatively, the temperature collected by the first thermistor 81 and the second thermistor 82 can also be sent to the first transmitter controller 61 or the second transmitter in the wireless charging transmitter 10 through the second wireless transmitter 72 . The controller 62 calculates the above-mentioned first current error ΔI ₁ and second current error ΔI ₂ through the first transmission controller 61 or the second transmission controller 62 . Alternatively, when both the _first thermistor 81 and the _second thermistor 82 are electrically connected to the above-mentioned charging manager 73, the charging manager 73 may calculate the above-mentioned The first current error ΔI ₁ and the second current error ΔI ₂ . Next, the charge manager 73 may generate a power request, eg, the above-mentioned second power request, according to the above-mentioned first current error ΔI ₁ and the second current error ΔI ₂ .

S303. Decrease at least one of the first charging power P1 and the second charging power P2 according to the second power request.

Specifically, when the wireless charging transmitter 10 performs the above-mentioned S303 process, the first transmission controller 61 may receive the above-mentioned second power request through the first wireless transmitter 71, and convert to the first voltage according to the second power request The circuit 102 inputs the first PWM signal. By controlling the duty cycle of the first PWM signal, the output voltage of the first voltage conversion circuit 102 can be reduced.

It can be seen from the above that when the first transmitting coil 121 and the first receiving coil 221 are circular coils, and the first voltage transmission gain k1 of the first charging branch 31 can be selected as 0.8 or 0.9, the first charging branch The frequency offset of 31 is 50KHz, and the frequency offset is larger. Therefore, the first transmitting coil 121 does not need to work at a fixed frequency, so the operating frequency of the first transmitting coil 121 can be adjusted to achieve the purpose of reducing the output power. In this case, the first transmit controller 61 may also input a second PWM signal to the first inverter circuit 111 according to the second power request, and reduce the output current of the first inverter circuit 111 by controlling the frequency of the second PWM signal , to achieve the purpose of reducing the first charging power P1.

In addition, it can be seen from the above that when the second transmitting coil 122 and the second receiving coil 222 are magnetic rod coils, and the second voltage transmission gain k2 of the second charging branch 32 can be selected as 1.05, the second charging branch The frequency offset of 32 is 20KHz, and the frequency offset is small. Therefore, the first transmitting coil 121 is suitable for working at a fixed frequency. Therefore, the second transmission controller 62 does not need to change the frequency of inputting the third PWM signal to the second inverter circuit 112, so that the first inverter circuit 111 operates at a fixed frequency.

In this case, in order to reduce the second charging power P2 output by the first inverter circuit 111, the wireless charging receiver 20 and the adapter 101 can send the second power request generated by the charging manager 73 through the SCP communication protocol. to the adapter 101, so that the adapter 101 can reduce the output voltage according to the second power request, so that the voltages received by the first voltage conversion circuit 102 and the second inverter circuit 112 are both reduced, so as to reduce the wireless The purpose of charging the first charging power P1 and the second charging power P2 output by the transmitter 10.

S304: Transmit the first charging power P1 and the second charging power P2. The above-mentioned S304 is the same as that of S204, and details are not repeated here.

S103. Charge the battery 200 with the third charging power P3. Wherein, P3=P1+P2; P3<P _max .

When the wireless charging receiver 20 performs the above-mentioned S205, since the first charging power P1 received by the first receiving coil 221 is reduced, the first output current _I1 output by the first receiving controller 201 is related to the first charging power P1. The target current I _G1 is the same or close to, so that the first charging power P1 provided by the first receiving controller 201 to the battery 200 is reduced.

Alternatively, when the second charging power P2 received by the second receiving coil 222 decreases, the second output current I ₂ output by the second receiving controller 202 is the same as or close to the second target current I _G2 , so that the second The second charging power P2 provided by the receiving controller 202 to the battery 200 is reduced. In this way, the third charging power P3 provided by the first charging branch 31 and the second charging branch 32 to the battery 200 is smaller than the maximum charging power P _max of the battery 200 , so as to charge the battery 200 with low power.

In this way, when the temperature of the receiving end coil in any one of the first charging branch 31 and the second charging branch 32 is relatively high, the wireless charging system 01 can follow the above preset charging strategy, according to the expected cooling The temperature target value is obtained, and the target current matching the temperature target value is obtained, and then the output voltage of the adapter 101 and the first voltage conversion circuit 102 in the wireless charging transmitter 10 is adjusted. Alternatively, the frequency of the first inverter circuit 111 may also be adjusted in combination, so that the first output current I ₁ output by the first charging branch 31 is the same as or close to the first target current I _G1 . Therefore, a reasonable proportion can be allocated to the magnitudes of the first output current I ₁ and the second output current I ₂ . In this case, the temperature of one charging branch with a reduced output current can be lowered to the target temperature, and finally the purpose of lowering the temperature of the receiving end coil can be achieved. It should be noted that the present application does not limit the mapping relationship between the temperature and the target current in the preset charging strategy. For example, when the temperature of any one of the first receiving coil 221 and the second receiving coil 222 is less than or equal to 28° C., the above mapping relationship can be set so that the temperature corresponding to the temperature less than or equal to 28° C. The target current values are all greater than zero. In this way, the values of the first output current I ₁ output by the first charging branch 31 and the second output current I ₂ output by the second charging branch 32 are both greater than zero.

Alternatively, in other embodiments of the present application, when the temperature of any one of the first receiving coil 221 and the second receiving coil 222 is greater than or equal to 42° C., in order to avoid overheating of the wireless charging receiver 20 If the components are damaged, the target current value corresponding to 42°C can be set to 0 when the above mapping relationship is set, so that a charging branch with a higher temperature can be stopped in time to prevent the charging branch from supplying the output current to the battery 200. purpose of lowering the temperature. For example, when the target current value of the first charging branch 31 is 0, the first transmit controller 61 may stop outputting the above-mentioned first PWM signal to the first voltage conversion circuit 102 and stop outputting the above-mentioned first PWM signal to the first inverter circuit 111 . The second PWM signal causes the first voltage conversion circuit 102 and the first inverter circuit 111 to stop working. At this time, the first charging branch 31 stops working. Similarly, when the target current value of the second charging branch 32 is 0, the second transmit controller 62 can stop outputting the third PWM signal to the second inverter circuit 112, so that the second inverter circuit 112 stops working . At this time, the second charging branch 32 stops working.

It should be noted that in the above, the temperature of the first receiving coil 221 and the temperature of the second receiving coil 222 are too high as the conditions that do not satisfy the high-power fast charging of the battery 200 as an example, and the reduction of the first charging branch 31 and an example of the output power of the second charging branch 32 . When the power of the battery 200 is close to full power. Alternatively, when the temperature of the battery 200 is in a very high temperature state as the condition for high-power fast charging of the battery 200 is not satisfied, the process of reducing the output power of the first charging branch 31 and the second charging branch 32 can be obtained in the same way. It is not repeated here. Since a communication connection is established between the wireless charging transmitter 10 and the wireless charging receiver 20 in the wireless charging system 01 by means of ASK modulation in-band communication, the in-band communication will make the wireless charging receiver 20, the first receiving control The voltage output by the controller 201 and the second receiving controller 202 to the battery 200 appears to jump randomly, resulting in an unstable phenomenon. Based on this, when the first charging branch 31 and the second charging branch 32 work at the same time, if the voltages output by the first receiving controller 201 and the second receiving controller 202 are unstable, the first receiving controller 201 cannot be guaranteed. The voltage output by the second receiving controller 202 is close to or the same, so that the current output by the first charging branch 31 and the second charging branch 32 cannot be further accurately controlled. Therefore, when the first charging branch 31 and the second charging branch 32 work at the same time, an out-of-band communication (eg, Bluetooth) method needs to be used to establish a communication connection.

In the above, the charging process of the wireless charging system 01 is described by taking as an example that the coils in the first charging branch 31 and the second charging branch 32 are both in the in-position state. In some embodiments of the present application, when the wireless charging receiver 20 serving as a mobile phone is placed on the wireless charging transmitter 10 serving as a charging base, and the first transmitting coil 121 and the wireless charging receiver 20 in the wireless charging transmitter 10 The positions of the first receiving coils 221 are aligned, the first transmitting coils 121 are in the in-position state, and the first charging branch 31 where the first transmitting coils 121 and the first receiving coils 221 are located can work. In addition, the positions of the second transmitting coil 122 in the wireless charging transmitter 10 and the second receiving coil 222 in the wireless charging receiver 20 are not aligned, the second transmitting coil 122 is in a non-position state, and the second transmitting coil 122 and The second charging branch 32 where the second receiving coil 222 is located cannot work. For example, when the mobile phone is placed on the charging base horizontally, the positions of the second transmitting coil 122 and the second receiving coil 222 cannot be aligned. In this case, S104 and S105 as shown in FIG. 9 may be performed.

S104, the first charging branch 31 works alone. The wireless charging system 01 executes the method of S104, which may specifically include S401 to S404 as shown in FIG. 14 .

S401 , sending a first in-position command of the first transmitting coil 121 . The function of the first in-position instruction is the same as described above, and will not be repeated here.

S402. Send a first power request.

Similarly, when the battery 200 can perform high-power fast charging, in the process of the wireless charging receiver 20 performing the above S402, the charging manager 73 can generate a first power request, and charge the wireless charging through the second wireless transceiver 72 Transmitter 10 sends the first power request. The first power request is used to indicate that the charging power provided by the first charging branch 31 in the wireless charging transmitter 10 to the battery 200 is the maximum charging power P _max of the battery 200 .

S403. Generate a first charging power P1 according to the first power request.

Similarly, in the process of the wireless charging transmitter 10 performing the above S203, the first transmission controller 61 can receive the above-mentioned first power request through the first wireless transmitter 71, control the duty cycle of the first PWM signal, and can control the The magnitude of the output voltage of the first voltage conversion circuit 102 .

It can be seen from the above that when the first transmitting coil 121 and the first receiving coil 221 are circular coils, the frequency offset of the first charging branch 31 is 50 KHz, and the frequency offset is relatively large. Therefore, the operating frequency of the first transmitting coil 121 can be adjusted to achieve the purpose of increasing the output power. In this case, the first transmit controller 61 can also control the frequency of the first square wave signal V _hb1 output by the first inverter circuit 111 by controlling the frequency of the second PWM signal according to the first power request, so that the first inverter The inverter circuit 111 can output the first charging power P1.

S404. Transmit the first charging power P1.

When the wireless charging transmitter 10 performs the process of S204, the first transmitting coil 121 may transmit the first charging power P1 to the first receiving coil 211 by transmitting the first alternating magnetic field.

S105. Charge the battery with the first charging power P1. where P1=P _max .

When the wireless charging receiver 20 performs the process of S105 above, the first receiving controller 201 can convert the alternating current output by the first receiving coil 221 into direct current, and output the first output voltage V _o1 and the first output current I to the battery 200 . ₁ to charge the battery 200 with the first charging power P1 (P1=V _o1 ×I ₁ ). Since P1=P _max , the charging power provided by the wireless charging transmitter 10 to the battery 200 can be the maximum charging power P _max of the battery 200 .

Similarly, when the above-mentioned conditions for high-power fast charging of the battery 200 are not satisfied, for example, when the temperature of the first receiving coil 221 is too high, the above-mentioned charging manager 73 can generate a second power request, so that the wireless charging transmitter 10 can reduce the power consumption. The first charging power P1 with low output, so that the charging power provided by the wireless charging transmitter 10 to the battery 200 is less than the maximum charging power P _max of the battery 200 (ie, P1 < P _max ), so as to realize low power charging.

Alternatively, in some other embodiments of the present application, when the wireless charging receiver 20 serving as a mobile phone is placed on the wireless charging transmitter 10 serving as a charging base, and the first transmitting coil 121 in the wireless charging transmitter 10 and the wireless charging The positions of the first receiving coil 221 in the receiver 20 are misaligned, the first transmitting coil 121 is in a non-positioned state (for example, the first transmitting coil 121 is loosely installed and displaced), the first transmitting coil 121 and the first transmitting coil 121 are not in position. The first charging branch 31 where the receiving coil 221 is located cannot work. In addition, the positions of the second transmitting coil 122 in the wireless charging transmitter 10 and the second receiving coil 222 in the wireless charging receiver 20 are aligned, the second transmitting coil 122 is in the in-position state, the second transmitting coil 122 and the second The second charging branch 32 where the receiving coil 222 is located can work. In this case, S106 and S107 as shown in FIG. 9 may be performed.

S106, the second charging branch 32 works alone.

The independent process of the second charging branch 32 can be obtained in the same way as the independent working process of the first charging branch 31 , which will not be repeated here.

S107 , using the second charging power P2 to charge the battery 200 . where P2=P _max .

The charging power provided by the second charging branch 32 to the battery 200 is the maximum charging power P _max of the battery 200 . Similarly, when the above-mentioned conditions for high-power fast charging of the battery 200 are not satisfied, for example, when the temperature of the second receiving coil 222 is too high, the above-mentioned charging manager 73 can generate a second power request, so that the wireless charging transmitter 10 can reduce power consumption. The second charging power P2 with low output, so that the charging power provided by the wireless charging transmitter 10 to the battery 200 is less than the maximum charging power P _max of the battery 200 (ie, P2<P _max ), so as to realize low power charging.

In addition, when the first charging branch 31 or the second charging branch 32 works alone, in order to prevent the other charging branch from starting to work due to misoperation, the wireless charging receiver 20 may further include a first charging circuit as shown in FIG. 10 . The isolating switch 231 and the second isolating switch 232 .

The first isolation switch 231 is electrically connected to the first receiving controller 201 and the second voltage converting circuit 210 , and the first receiving controller 201 is used to control the opening and closing of the first isolation switch 231 . The second isolation switch 232 is electrically connected to the second receiving controller 202 and the second voltage converting circuit 210 . The second receiving controller 202 is used to control the opening and closing of the second isolation switch 232. When the first charging branch 31 works alone, the first receiving controller 201 controls the first isolation switch 231 to turn on, and signal transmission can be performed between the first receiving controller 201 and the second voltage converting circuit 210 . The second receiving controller 202 controls the second isolation switch 232 to be disconnected, and the second receiving controller 202 is disconnected from the second voltage converting circuit 210 . On the contrary, when the second charging branch 32 works alone, the second receiving controller 202 controls the second isolation switch 232 to turn on, and signal transmission can be performed between the second receiving controller 202 and the second voltage converting circuit 210 . The first receiving controller 201 controls the first isolation switch 231 to be disconnected, and the first receiving controller 201 is disconnected from the second voltage converting circuit 210 .

To sum up, during the working process of the wireless charging system 01, the first charging branch 31 or the second charging branch 32 can be independently controlled to work independently according to the support of the charging base and the temperature limiting measures of the charging branch. In addition, the first charging branch 31 and the second charging branch 32 can also be controlled to work at the same time, so that the charging method is more flexible. After the wireless charging system 01 implements charging in any of the above-mentioned manners, the charging process can be ended. For example, the wireless charging receiver 20 sends out a warning message that the charging is completed. The warning information may use a light warning, a sound warning, or a warning image to remind the user that the charging process has ended.

Example 2

The difference from Example 1 is that in this example, the first transmitting coil 121 and the first receiving coil 221 in the first charging branch 31 shown in FIG. 14 are the above-mentioned magnet bar coil 50 (as shown in FIG. 4D ), The second transmitting coil 122 and the second receiving coil 222 in the second charging branch 32 are the above-mentioned circular coils 40 (as shown in FIG. 4D ). In this case, the operating frequencies of the first transmitting coil 121 and the first receiving coil 221 in the first charging branch 31 (for example, in the range of 330KHz˜350KHz) are higher than that of the second transmitting coil in the second charging branch 32 . The operating frequency of the coil 122 and the second receiving coil 222 (eg, below 210KHz).

In addition, the first voltage conversion circuit 102 in FIG. 14 is a booster circuit, and the first voltage transfer gain k1 of the first charging branch 31 is smaller than the second voltage transfer gain k2 of the second charging branch 32, ie k1<k2. In this case, the number of turns Nb1 of the first receiving coil 221, the number of turns Na1 of the first transmitting coil 121, the number of turns Nb2 of the second receiving coil 222, and the number of turns Na2 of the second transmitting coil 122 are set in the same manner as described above , and will not be repeated here.

The process of setting the first voltage transmission gain k1 of the first charging branch 31 to satisfy k1<1, and the second voltage transmission gain k2 of the second charging branch 32 to satisfy k2≥1 is the same as described above, and will not be repeated here. In addition, according to the temperature limiting measures of the charging branch, when the first output current _I1 output by the first charging branch 31 and the second output current _I2 output by the second charging branch 32 meet different needs, the The adjustment method of the voltage output by the first transmitting coil 121 at the transmitting end of the charging branch 31 and the voltage output by the second transmitting coil 122 serving as the transmitting end of the second charging branch 32 can be obtained in the same way. Repeat.

The difference is that since the second transmitting coil 122 and the second receiving coil 222 in the second charging branch 32 in this example are the above-mentioned circular coils 40 , the second transmitting coil 122 and the second receiving coil 222 at this time The frequency offset of the second charging branch 32 may be relatively large, for example, 50KHz. Therefore, the second transmitting coil 122 does not need to work at a fixed frequency. Therefore, in the process of adjusting the second output current I ₂ output by the second charging branch 32 , the operating frequency of the second transmitting coil 122 can be adjusted. In this case, the second transmission controller 62 can input the second PWM signal to the first inverter circuit 111 according to the power request sent by the charging manager 73, and adjust the first inverter circuit by controlling the frequency of the second PWM signal. The purpose of the output current of circuit 111.

The above example 1 and example 2 are both described by taking the example that the first voltage conversion circuit 102 in the wireless charging transmitter 10 is a boosting circuit. In other embodiments of the present application, the first voltage conversion circuit 102 is a step-down (buck) circuit.

Example three

This example is the same as Example 1 in that the first transmitting coil 121 and the first receiving coil 221 in the first charging branch 31 in FIG. 14 are the above-mentioned circular coils 40 (as shown in FIG. 4D ), and the second The second transmitting coil 122 and the second receiving coil 222 in the charging branch 32 are the above-mentioned magnetic bar coil 50 (as shown in FIG. 4D ). In this case, the operating frequency of the second transmitting coil 122 and the second receiving coil 222 in the second charging branch 32 (for example, in the range of 330KHz˜350KHz) is higher than that of the first transmitting coil in the first charging branch 31 . 121 and the operating frequency of the first receiving coil 221 (for example, below 210KHz).

The difference between this example and the first example is that the first voltage conversion circuit 102 in FIG. 14 is a step-down circuit. In this case, the first voltage transfer gain k1 of the first charging branch 31 is greater than the second voltage transfer gain k2 of the second charging branch 32, that is, k1>k2. Based on this, the number of turns Nb1 of the first receiving coil 221 may be greater than the number of turns Na1 of the first transmitting coil 121 , that is, Nb1 > Na1 . At this time, the ratio of the output voltage to the input voltage of the transformer formed by the first transmitting coil 121 and the first receiving coil 221 as a circular coil is >1, so that k1 >1. In addition, the number of turns Nb2 of the second receiving coil 222 is less than or equal to the number of turns Na2 of the second transmitting coil 122, that is, Nb2≤Na2. At this time, the ratio of the output voltage to the input voltage of the transformer formed by the second transmitting coil 122 and the second receiving coil 222 as the magnetic bar coil is less than or equal to 1, so that k2≤1.

Similarly, the first voltage transfer gain k1 of the first charging branch 31 satisfies k1>1, and the setting process of the second voltage transfer gain k2 of the second charging branch 32 satisfying k2≤1 is the same as described above and will not be repeated here. In addition, according to the temperature limiting measures of the charging branch, when the first output current _I1 output by the first charging branch 31 and the second output current _I2 output by the second charging branch 32 meet different needs, the The method for adjusting the voltage output by the first transmitting coil 121 at the transmitting end of the charging branch 31 and the method for adjusting the voltage output by the second transmitting coil 122 serving as the transmitting end of the second charging branch 32 are the same as described above, and will not be repeated here. Repeat.

Example four

The same between this example and the second example is that the first transmitting coil 121 and the first receiving coil 221 in the first charging branch 31 shown in FIG. 14 are the above-mentioned magnet bar coil 50 (as shown in FIG. 4D ). The second transmitting coil 122 and the second receiving coil 222 in the two charging branches 32 are the above-mentioned circular coils 40 (as shown in FIG. 4D ). In this case, the operating frequencies of the first transmitting coil 121 and the first receiving coil 221 in the first charging branch 31 (for example, in the range of 330KHz˜350KHz) are higher than that of the second transmitting coil in the second charging branch 32 . The operating frequency of the coil 122 and the second receiving coil 222 (eg, below 210KHz).

The difference between this example and the second example is that the first voltage conversion circuit 102 in FIG. 14 is a step-down circuit. In this case, the first voltage transfer gain k1 of the first charging branch 31 is greater than the second voltage transfer gain k2 of the second charging branch 32, that is, k1>k2. Based on this, the number of turns Nb1 of the first receiving coil 221, the number of turns Na1 of the first transmitting coil 121, the number of turns Nb2 of the second receiving coil 222, and the number of turns Na2 of the second transmitting coil 122 are set in the same manner as described above. It is not repeated here.

To sum up, no matter whether the first voltage conversion circuit 102 in the wireless charging transmitter 10 is a boost circuit or a step-down circuit, as long as the voltage transfer gain of the charging branch without the first voltage conversion circuit 102 is set close to 1, for example When greater than or equal to 1, the voltage gain of the other charging branch is less than 1. Alternatively, when the voltage transfer gain of the charging branch in which the first voltage conversion circuit 102 is not set is less than or equal to 1, the voltage gain of the other charging branch is greater than 1. Therefore, the voltages output by the first receiving controller 201 and the second receiving controller 202 connected in parallel in the wireless charging receiver 20 can be similar to or the same, so that the first output current I 1 and the first output current I ₁ and the first output current I 1 output by the first charging branch 31 and the second receiving controller 202 can be similar or identical. The second output current I ₂ output by the two charging branches 32 is precisely controlled.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art who is familiar with the technical scope disclosed in the present application can easily think of changes or replacements, which should cover within the scope of protection of this application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A wireless charging transmitter, characterized in that the wireless charging transmitter is used to output an alternating magnetic field to a wireless charging receiver; the wireless charging transmitter comprises:

a first voltage conversion circuit, electrically connected to the adapter, for converting the DC power output by the adapter into DC power;

a first inverter circuit, electrically connected to the first voltage conversion circuit, for converting the direct current output by the first voltage conversion circuit into a first square wave signal;

a first transmitting coil, electrically connected to the first inverter circuit, for converting the first square wave signal into a first alternating magnetic field; the wireless charging receiver is used for receiving the first alternating magnetic field a magnetic field circuit, wherein the ratio of the first output voltage V o1 output to the battery in the wireless charging receiver to the input voltage V in1 of the first inverter circuit is a first voltage transmission gain k1;

a second inverter circuit, electrically connected to the adapter, for converting the DC power output by the adapter into a second square wave signal;

The second transmitting coil is electrically connected to the second inverter circuit, and is used for converting the second square wave signal into a second alternating magnetic field; the wireless charging receiver is used for receiving the second alternating magnetic field. the magnetic field circuit, the ratio of the second output voltage V o2 output to the battery to the input voltage V in2 of the second inverter circuit is the second voltage transmission gain k2;

Wherein, the first voltage transmission gain k1 is different from the second voltage transmission gain k2, and the first output voltage V o1 and the second output voltage V o2 are the same.
The wireless charging transmitter according to claim 1, wherein the first voltage conversion circuit is a boost circuit, and the first voltage transmission gain k1 is smaller than the second voltage transmission gain k2.
The wireless charging transmitter according to claim 2, wherein,

In the wireless charging receiver, the number of turns of the first receiving coil for receiving the first alternating magnetic field is smaller than the number of turns of the first transmitting coil;

In the wireless charging receiver, the number of turns of the second receiving coil for receiving the second alternating magnetic field is greater than or equal to the number of turns of the second transmitting coil.
The wireless charging transmitter according to claim 1, wherein the first voltage conversion circuit is a step-down circuit, and the first voltage transmission gain k1 is greater than the second voltage transmission gain k2.
The wireless charging transmitter according to claim 4, wherein,

In the wireless charging receiver, the number of turns of the first receiving coil for receiving the first alternating magnetic field is greater than the number of turns of the first transmitting coil;

In the wireless charging receiver, the number of turns of the second receiving coil for receiving the second alternating magnetic field is less than or equal to the number of turns of the second transmitting coil.
The wireless charging transmitter according to any one of claims 1-5, wherein,

The wireless charging transmitter also includes:

a first matching capacitor, connected in series with the first transmitting coil, and forming a first series resonance network with the first transmitting coil;

The second matching capacitor is connected in series with the second transmitting coil, and forms a second series resonant network with the second transmitting coil; wherein, the operating frequency of the first series resonant network is the same as that of the second series resonant network. The working frequency is different.
The wireless charging transmitter according to claim 6, wherein,

The wireless charging transmitter further includes a first magnetic rod;

When the operating frequency of the first series resonant network is lower than the operating frequency of the second series resonant network, the first transmitting coil is a circular coil; the second transmitting coil is wound on the first magnetic Magnetic rod coils on rods;

or,

When the operating frequency of the first series resonant network is greater than the operating frequency of the second series resonant network, the first transmitting coil is a magnetic bar coil wound on the first magnetic bar; the second The transmitting coil is a circular coil.
The wireless charging transmitter according to any one of claims 1-7, wherein,

The wireless charging transmitter also includes:

a first transmit controller, electrically connected to the first voltage conversion circuit and the first inverter circuit, the first transmit controller is configured to input a first pulse width modulated PWM signal to the first voltage conversion circuit, to control the output voltage of the first voltage conversion circuit, and to input a second PWM signal to the first inverter circuit to control the frequency of the first square wave signal;

a second transmission controller, electrically connected to the second inverter circuit, and used for inputting a third PWM signal to the second inverter circuit to control the frequency of the second square wave signal .
The wireless charging transmitter according to any one of claims 1-8, wherein 0<|k1-k2|≤0.3.
A wireless charging receiver, comprising:

Battery;

a first receiving coil for receiving the first alternating magnetic field output by the first transmitting coil in the wireless charging transmitter, and converting the first alternating magnetic field into alternating current;

a first receiving controller, electrically connected to the first receiving coil and the battery, for converting the alternating current generated by the first receiving coil into direct current and outputting it to the battery; the first receiving controller The ratio of the first output voltage V o1 output to the battery and the input voltage V in1 of the first inverter circuit electrically connected to the first transmitting coil in the wireless charging transmitter is the first voltage transmission gain k1;

The second receiving coil is used for receiving the second alternating magnetic field output by the second transmitting coil in the wireless charging transmitter, and converting the second alternating magnetic field into alternating current;

The second receiving controller is electrically connected to the second receiving coil and the battery, and is used for converting the alternating current generated by the second receiving coil into direct current and outputting it to the battery; the second receiving controller The ratio of the second output voltage V o2 output to the battery to the input voltage V in2 of the second inverter circuit electrically connected to the second transmitting coil in the wireless charging transmitter is the second voltage transmission gain k2;

Wherein, the first voltage transmission gain k1 is different from the second voltage transmission gain k2, and the first output voltage V o1 and the second output voltage V o2 are the same.
The wireless charging receiver according to claim 10, wherein the first voltage transmission gain k1 is smaller than the second voltage transmission gain k2;

The number of turns of the first receiving coil is smaller than the number of turns of the first transmitting coil;

The number of turns of the second receiving coil is greater than or equal to the number of turns of the second transmitting coil.
The wireless charging receiver according to claim 10, wherein the first voltage transmission gain k1 is greater than the second voltage transmission gain k2;

The number of turns of the first receiving coil is greater than the number of turns of the first transmitting coil;

The number of turns of the second receiving coil is less than or equal to the number of turns of the second transmitting coil.
The wireless charging receiver according to any one of claims 10-12, wherein,

The wireless charging receiver further includes a second magnetic rod;

The first receiving coil is a circular coil, and the second receiving coil is a bar magnet coil wound on the second magnet bar; or, the first receiving coil is a coil wound on the second magnetic bar. The magnetic bar coil on the rod, the second receiving coil is a circular coil.
The wireless charging receiver according to any one of claims 10-13, wherein the wireless charging receiver further comprises:

a first thermistor for sensing the first temperature T 1 of the first receiving coil;

a second thermistor for sensing the second temperature T 2 of the second receiving coil;

a charge manager, electrically connected to the first thermistor and the second thermistor, the charge manager is configured to generate a power request according to the first temperature T1 and the second temperature T2, the power The request is used to regulate the charging power output by the wireless charging transmitter.
The wireless charging receiver according to any one of claims 10-14, wherein the wireless charging receiver further comprises:

A second voltage conversion circuit is electrically connected to the battery, the first receiving controller and the second receiving controller, and is used to convert at least one of the first receiving controller and the second receiving controller converting an output voltage into a charging voltage of the battery;

a first isolation switch, which is electrically connected to the first receiving controller and the second voltage conversion circuit; the first receiving controller is used to control the opening and disconnection of the first isolation switch;

The second isolation switch is electrically connected with the second receiving controller and the second voltage conversion circuit; the second receiving controller is used to control the opening and disconnection of the second isolation switch.
The wireless charging receiver according to any one of claims 10-15, wherein 0<|k1-k2|≤0.3.
A wireless charging system, characterized by comprising an adapter, the wireless charging transmitter according to any one of claims 1-9, and the wireless charging receiver according to any one of claims 10-16; the adapter It is electrically connected with the first voltage conversion circuit and the second inverter circuit in the wireless charging transmitter.