CN105576838A - Wireless energy receiving device, wireless energy transmission system and method thereof - Google Patents

Abstract

The invention provides a wireless energy receiving device, a wireless energy transmission system and a method thereof. The wireless energy receiving device comprises a coil, a rectifying circuit, a direct current output port and a judging circuit. The coil wirelessly receives energy from a wireless energy transfer device. The rectifying circuit is coupled with the coil and converts an alternating current voltage from the coil into a direct current output voltage. The direct current output port is coupled with the rectifying circuit and provides direct current output voltage. The judging circuit is coupled with the coil, the rectifying circuit and the direct current output port, monitors direct current output voltage of the direct current output port, and informs the wireless energy transmission device to adjust output power of the wireless energy transmission device according to the direct current output voltage. Therefore, the wireless energy transmission device adjusts the output power according to the signal related to the DC output voltage returned by the wireless energy receiving device.

Description

Wireless energy receiving device, wireless energy transmission system and method thereof

technical field

The present invention relates to a wireless energy transmission, and in particular to a wireless energy receiving device, a wireless energy transmission system and a method thereof.

Background technique

Please refer to FIG. 1 , which is a circuit block diagram of a traditional wireless energy transmission system. Existing wireless energy transfer systems have multiple implementations, including at least three of the above, magnetic coupling, magnetic resonance, and electric field coupling. The system in Figure 1 uses magnetic coupling to transmit energy. The wireless energy transmission device 11 provides an AC voltage to the wireless energy receiving device 12, wherein the control circuit of the wireless energy transmission device 11 is omitted in FIG. 1 , and only the input voltage RXI and the coil for energy transmission are shown. The coupling coil 121 of the wireless energy receiving device 12 couples the alternating current AC and provides it to the rectification circuit 122, and the rectification circuit 122 transmits the rectified direct current DC to the DC-DC converter 124, and the DC output port 125 converts the DC-DC converter ( DCtoDCconverter) 124 provides an output voltage to an external circuit. The judging circuit 123 controls the DC-DC converter 124 according to the output voltage of the DC output port 125 and the AC power of the coupling coil 121 .

However, in order to adjust the power transmission, not only the wireless energy transmission device 11 itself has a mechanism to modulate the output power, but the traditional wireless energy receiving device 12 also controls the output voltage by itself through the DC-DC converter 124 . In this way, the multi-level power and voltage modulation may reduce the power conversion efficiency.

Contents of the invention

The embodiment of the present invention provides a wireless energy receiving device, a wireless energy transmission system and a wireless energy transmission method, so that the wireless energy transmitting device adjusts the output power according to the signal about the DC output voltage sent back by the wireless energy receiving device.

An embodiment of the present invention provides a wireless energy receiving device, including a coil, a rectifier circuit, a DC output port, and a judgment circuit. The coil wirelessly receives energy from a wireless energy transmission device. The rectifier circuit is coupled to the coil and converts an AC voltage from the coil into a DC output voltage. The DC output port is coupled to the rectification circuit to provide a DC output voltage. The judging circuit is coupled to the coil, the rectifier circuit and the DC output port, monitors the DC output voltage of the DC output port, and notifies the wireless energy transmission device to adjust an output power of the wireless energy transmission device according to the DC output voltage.

An embodiment of the present invention provides a wireless energy transmission system, including a wireless energy transmission device and a wireless energy reception device. The wireless energy transmission device wirelessly provides an output power. The wireless energy receiving device includes a coil, a rectifying circuit, a DC output port and a judging circuit. The coil wirelessly receives energy from a wireless energy transmission device. The rectifier circuit is coupled to the coil and converts an AC voltage from the coil into a DC output voltage. The DC output port is coupled to the rectification circuit to provide a DC output voltage. The judgment circuit is coupled to the coil, the rectifier circuit and the DC output port, monitors the DC output voltage of the DC output port, and notifies the wireless energy transmission device to adjust an output power of the wireless energy transmission device according to the DC output voltage.

An embodiment of the present invention provides a wireless energy transmission method, including the following steps. Firstly, a wireless energy transmitting device is used to transmit a power to a wireless energy receiving device. Then, a DC output voltage of the wireless energy receiving device is detected, and an indication signal representing the DC output voltage is sent to the wireless energy transmitting device by the wireless energy receiving device. Then, the wireless energy transmission device is used to adjust an output power of the wireless energy transmission device according to the indication signal representing the DC output voltage.

Embodiments of the present invention provide a wireless energy receiving device, a wireless energy transmission system, and a wireless energy transmission method. modulation. Compared with the traditional wireless energy transmission system, the wireless energy receiving device, the wireless energy transmission system and the wireless energy transmission method according to the embodiments of the present invention have one less level of DC-DC conversion, which can reduce the cost of circuit materials and heat-generating components , but also can improve the power conversion efficiency.

In order to enable a further understanding of the features and technical content of the present invention, please refer to the following detailed description and accompanying drawings of the present invention, but these descriptions and accompanying drawings are only used to illustrate the present invention, rather than claiming the rights of the present invention any limitations on the scope.

Description of drawings

Fig. 1 is a circuit block diagram of a traditional wireless energy transmission system.

Fig. 2 is a circuit block diagram of a wireless energy transmission system provided by an embodiment of the present invention.

Fig. 3 is a waveform diagram of the operating voltage of the wireless energy transmission system provided by the embodiment of the present invention.

Fig. 4 is a flowchart of a wireless energy transmission method provided in an embodiment of the present invention.

Fig. 5 is a flowchart of a wireless energy transmission method provided in another embodiment of the present invention.

detailed description

[Implementation of wireless energy receiving device and wireless energy transmission system]

Please refer to FIG. 2 . FIG. 2 is a circuit block diagram of a wireless energy transmission system provided in an embodiment of the present invention. The wireless energy transmission system 2 includes a wireless energy transmission device 21 and a wireless energy receiving device 22, the wireless energy transmission device 21 can be regarded as an energy transmitting end (TX), and the wireless energy receiving device 22 can be regarded as an energy receiving end (RX). The wireless energy transmitting device 21 can transmit energy to the wireless energy receiving device 22 by using, for example, magnetic coupling, magnetic resonance and electric field coupling, or other wireless transmission mechanisms. The wireless energy transmission device 21 of this embodiment, for example, uses a magnetic coupling method to feed AC input voltage TXI into its coil through a coil, and the coupling coil 221 of the wireless energy receiving device 22 uses magnetic coupling to couple energy. Here, the coupling coil 221 may be generally referred to as a coil, the coil used for magnetic coupling may be referred to as a coupling coil, and the coil applied to magnetic resonance may be referred to as a resonant coil. The present invention does not limit the types of coils.

The wireless energy receiving device 22 includes a coupling coil 221 , a rectification circuit 222 , a DC output port 225 , a judging circuit 223 and a communication circuit 226 . The judging circuit 223 uses the communication circuit 226 to transmit the indication signal IND representing the output voltage RXO to the wireless energy transmission device 21 . The judging circuit 223 can be, for example, a microcontroller (MCU). In another embodiment, the communication circuit 226 can be integrated with the judging circuit 223, and the communication circuit 226 only provides the function of wirelessly transmitting signals.

The coupling coil 221 wirelessly receives the energy of the wireless energy transmission device 21 . The rectifier circuit 222 is coupled to the coupling coil 221 to convert the AC voltage (corresponding to the input voltage TXI of the wireless energy transmission device 21 ) from the coupling coil 221 into a DC output voltage RXI. The rectifier circuit 222 can be, for example, a full-bridge rectifier circuit or a half-bridge rectifier circuit, but the present invention is not limited thereto, and those skilled in the art can change the type and design of the rectifier circuit as required.

The DC output port 225 is coupled to the rectification circuit 222 to provide a DC output voltage RXO. The judgment circuit 223 is coupled to the coupling coil 223, the rectifier circuit 222 and the DC output port, monitors the DC output voltage RXO of the DC output port 225, and notifies the wireless energy transmission device 21 to adjust the output power of the wireless energy transmission device 21 according to the DC output voltage RXO. In one embodiment, the judging circuit 223 communicates with the wireless energy transmission device using amplitude shift keying (ASK) or frequency shift keying (FSK), but the present invention is not limited thereto. The wireless energy transmitting device 21 adjusts the output power transmitted by the wireless energy transmitting device 21 according to a transfer function between the wireless energy transmitting device 21 and the wireless energy receiving device 22 and the DC output voltage RXO. In other words, the wireless energy receiving device 22 in this embodiment does not control and adjust the DC output voltage and power itself, but returns an indication signal about the DC output voltage RX0 to the wireless energy transmitting device 21 .

Compared with the traditional wireless energy receiving device 12 in FIG. 1 , which has a DC-DC converter 124, the wireless energy receiving device 22 in this embodiment eliminates the DC-DC converter 124, providing more Simple design solution. The wireless energy receiving device 22 of this embodiment can transmit back the different DC output voltages generated by different load conditions to the wireless energy transmitting device 21, and the wireless energy transmitting device 21 only needs to perform power modulation, and the wireless energy receiving device 22 It is not necessary to control the DC output voltage RXO of the DC output port 225 itself. In short, after the wireless energy receiving device 22 (RX) receives the power of the wireless energy transmitting device 21 (TX), the wireless energy receiving device 22 (RX) transmits an indication signal IND corresponding to the output voltage, and the wireless energy transmitting device 21 When (TX) receives the indication signal IND, the wireless energy transmission device 21 (TX) performs power modulation according to the indication signal IND.

Furthermore, regarding the power modulation of the wireless energy transmission device 21 , the wireless energy transmission device 21 may utilize, for example, pulse width modulation (PWM) or pulse frequency modulation (PFM) to adjust its input voltage TXI. However, the present invention does not limit the way of adjusting the output power of the wireless energy transmission device 21 .

In practical application, in order to avoid problems caused by unstable output voltage, such as voltage overshoot (overshoot phenomenon). When the system starts to operate, the wireless energy transmission device 21 can first provide the maximum power to obtain the relevant parameters of wireless energy transmission, such as the transfer function (transfer function), or it can not be the maximum power but can be used by the user or the designer A predetermined power defined. The above-mentioned transfer function is changed according to the different circuits of the wireless energy transmitting device 21 and the wireless energy receiving device 22, for example, according to different circuit forms such as full bridge, half bridge and other AC-DC conversion circuits, rectification circuits, etc., the transfer function will also vary accordingly. Change. The present invention does not limit the form of the relevant power circuit, nor does it limit the conversion function corresponding to the circuit. The conversion function is actually different due to the design of the relevant power circuit.

Please refer to FIG. 2 and FIG. 3 at the same time. FIG. 3 is a waveform diagram of an operating voltage of a wireless energy transmission system provided in an embodiment of the present invention. As shown in FIG. 3 , the identification phase is a communication process between the wireless energy transmitting device 21 and the wireless energy receiving device 22 , and after the identification phase, enters the power transmission phase. The wireless energy transmitting device 21 generates an input voltage TXI, so that the wireless energy receiving device 22 receives energy through, for example, magnetic coupling to generate an input voltage RXI. The wireless energy receiving device 22 generates an indication signal IND according to the DC output voltage RXO. The wireless energy transmission device 21 adjusts the input voltage TXI according to the indication signal IND, thereby adjusting the input voltage RXI, thereby adjusting the DC output voltage RXO. For example: when fully loaded (fullload), the DC output voltage RXO is greater than the target voltage VTA, at this time according to the indication signal IND wireless energy transmission device 21 reduces the input voltage TXI, so that the input voltage RXI of the wireless energy receiving device 22 and the DC output voltage RXO are thus Gradually decreases. Regarding the modulation of the voltage, it may be a periodic change as shown in FIG. 3 , but the present invention is not limited thereto. It is worth mentioning that, in the full-load condition shown in FIG. 3 , the way for the DC output voltage RXO to approach the target voltage VTA is to approach the target voltage VTA successively, but the process is not limited to be greater than or less than the target voltage VTA. Furthermore, as shown in FIG. 3 , when there is no load, the DC output voltage RXO is substantially greater than the target voltage VTA. At this time, the wireless energy transmission device 21 reduces the input voltage TXI according to the indication signal IND, so that the wireless energy receiving device Therefore, the input voltage RXI and the DC output voltage RXO of 22 decrease gradually, and finally approach the target voltage VTA.

[Implementation of wireless energy transfer method]

Please refer to FIG. 2 and FIG. 4 at the same time. FIG. 4 is a flowchart of a wireless energy transmission method provided in an embodiment of the present invention. The flow of this embodiment can be realized by the wireless energy transmission system 2 in FIG. 2 . First, in step S110 , the wireless energy transmitting device 21 is used to transmit power to the wireless energy receiving device 21 . Then, in step S120 , the DC output voltage RXO of the wireless energy receiving device 22 is detected, and the wireless energy receiving device 22 transmits an indication signal IND representing the DC output voltage RXO to the wireless energy transmitting device 21 . Next, in step S130 , the wireless energy transmission device 21 is used to adjust the output power of the wireless energy transmission device 21 according to the indication signal IND representing the DC output voltage RXO. In step S130, in one embodiment, in detail, the wireless energy transmitting device 21 is used to adjust the transmission function of the wireless energy transmitting device 21 according to the transfer function between the wireless energy transmitting device 21 and the wireless energy receiving device 22 and the indication signal IND. output power. In practical applications, steps S110 , S120 to S130 in FIG. 4 can be used for various load conditions, including the full load and no load conditions described in FIG. 3 . It is worth mentioning that the transfer function of the above step S130 may be known in advance during system design. In actual application, the real transfer function of the system may also be different from the pre-designed one. In this way, the relevant parameters of the actual transfer function can be obtained by using the subsequent process in FIG. 5 .

Next, after the above step S130 is completed, step S110 may be performed again. On the other hand, in actual implementation, step S110 can be continuously performed. The above sequence of steps S110 , S120 , and S130 is used to adjust the output power according to the load condition, so that the DC output voltage RXO can be adjusted periodically.

Please refer to FIG. 5 , which is a flowchart of a wireless energy transmission method provided in another embodiment of the present invention. In step S210 , the wireless energy transmitting device 21 transmits predetermined power to the wireless energy receiving device 22 . The predetermined power may be, for example, the maximum power, but the present invention is not limited thereto. Next, in step S220 , according to the transfer function, the DC output voltage RXO of the wireless energy receiving device 22 and the input voltage TXI of the wireless energy transmitting device 21 , relevant parameters of the transfer function are obtained. Regarding the transfer function, taking the way of magnetic coupling energy transfer as an example, the transfer function is Vout=Vin*(Ns/Np)*D*G, where Vout is the output voltage (RXO), Vin is the input voltage (TXI), Ns is the number of coil turns of the wireless energy receiving device 22, Np is the number of coil turns of the wireless energy transmitting device 21, D is the duty cycle (Dutycycle) of the wireless energy transmitting device 21, and G is the gain (gain) of the transfer function. Then step by step S230, S240, S250, wherein the steps S230, S240, S250 are the same as the steps S110, S120, S130 in FIG. In other words, step S210 and step S220 can be performed before step S110 in the flow chart of FIG. For example: Gain G. However, the present invention is not limited thereto. The energy transmission method of the wireless energy transmission system may also be magnetic resonance, electric field coupling, and the like. According to the wireless energy transmission method used, the above transfer function may also be different.

In another embodiment, when the predetermined power in step S210 is the maximum power, after step S210 ends, step S220 may also include setting a preset voltage for judging the no-load condition under the condition of no load , and comparing the DC output voltage with the preset voltage, it can be known whether the output voltage of the wireless energy receiving device is too high, which can be used to solve the problem of voltage overshoot. If the output voltage is actually too high under no-load condition, the wireless energy transmission device can reduce the output power transmitted by the wireless energy transmission device according to the indication signal of the wireless energy receiving device, so as to avoid voltage overshoot.

[Possible effects of the implementation]

To sum up, in the wireless energy receiving device, wireless energy transmission system and wireless energy transmission method provided by the embodiments of the present invention, the wireless energy receiving device does not have a DC-DC converter (DCtoDC converter), and only the wireless energy at the energy transmitting end The transmitting device performs power modulation once. Compared with the traditional wireless energy transmission system, the wireless energy receiving device, the wireless energy transmission system and the wireless energy transmission method according to the embodiments of the present invention have one less level of DC-DC conversion, which can reduce the cost of circuit materials and heat-generating components , but also can improve the power conversion efficiency.

The above description is only the embodiment of the present invention, which is not intended to limit the patent scope of the present invention.

Symbol Description

11, 21: Wireless energy transmission device

2: Wireless energy transmission system

12, 22: Wireless energy receiving device

121, 221: coupling coil

122, 222: Rectifier circuit

123, 223: judgment circuit

124: DC-DC Converter

125, 225: DC output ports

AC: alternating current

DC: direct current

TXI, RXI: input voltage

IND: indication signal

RXO: DC output voltage

226: Communication circuit

VTA: target voltage

S110, S120, S130, S210, S220, S230, S240, S250: step process

Claims (10)

1. a wireless energy receiving system, is characterized in that, comprising:

One coil, the energy of wireless receiving one wireless energy conveyer;

One rectification circuit, couples described coil, and the alternating voltage from described coil is converted to a VD;

One direct current output port, couples described rectification circuit, provides described VD; And

One decision circuitry, couple described coil, described rectification circuit and described DC output end mouth, monitor the described VD of described DC output end mouth, and notify that described wireless energy conveyer adjusts a power output of described wireless energy conveyer according to described VD.

2. wireless energy receiving system according to claim 1, wherein said decision circuitry utilizes amplitude shift key modulation (ASK) or shift keying modulation (FSK) and communicates with described wireless energy conveyer.

3. wireless energy receiving system according to claim 1, wherein said wireless energy conveyer adjusts according to the transfer function between described wireless energy conveyer and described wireless energy receiving system and described VD the described power output that described wireless energy conveyer transmits.

4. a wireless energy transfer system, is characterized in that, comprising:

One wireless energy conveyer, wirelessly provides a power output; And

One wireless energy receiving system, comprising:

One coil, the energy of wireless energy conveyer described in wireless receiving;

One rectification circuit, couples described coil, and the alternating voltage from described coil is converted to a VD;

One direct current output port, couples described rectification circuit, provides described VD; And

One decision circuitry, couple described coil, described rectification circuit and described DC output end mouth, monitor the described VD of described DC output end mouth, and notify that described wireless energy conveyer adjusts a power output of described wireless energy conveyer according to described VD.

5. wireless energy transfer system according to claim 4, wherein said decision circuitry is by described coil and utilize amplitude shift key modulation (ASK) or shift keying modulation (FSK) and communicate with described wireless energy conveyer.

6. wireless energy transfer system according to claim 4, wherein said wireless energy conveyer adjusts according to the transfer function between described wireless energy conveyer and described wireless energy receiving system and described VD the described power output that described wireless energy conveyer transmits.

7. a wireless energy transfer method, is characterized in that, comprising:

A wireless energy conveyer is utilized to transmit power to an one wireless energy receiving system;

Detect a VD of described wireless energy receiving system, and utilize the transmission of described wireless energy receiving system to represent an index signal of described VD to described wireless energy conveyer;

Described wireless energy conveyer is utilized also to adjust a power output of described wireless energy conveyer according to the described index signal representing described VD.

8. wireless energy transfer method according to claim 7, the step wherein adjusting the described power output of described wireless energy conveyer also comprises:

Utilize described wireless energy conveyer and adjust according to the transfer function between described wireless energy conveyer and described wireless energy receiving system and described index signal the described power output that described wireless energy conveyer transmits.

9. wireless energy transfer method according to claim 7, also comprises:

Described wireless energy conveyer is utilized to transmit a predetermined power to described wireless energy receiving system; And

According to a transfer function, the described VD of described wireless energy receiving system and an input voltage of described wireless energy conveyer, obtain the relevant parameter of described transfer function.

10. wireless energy transfer method according to claim 9, wherein said transfer function is Vout=Vin* (Ns/Np) * D*G, the gain that the duty ratio that the coil turn of wireless energy conveyer described in the coil turn that wherein Vout is described output voltage, Vin is described input voltage, Ns is described wireless energy receiving system, Np, D are described wireless energy conveyers, G are described transfer functions.