Multi-load wireless power transmission system based on switched capacitor compensation

Abstract

The invention provides a multi-load wireless electric energy transmission system based on switched capacitor compensation, and the system comprises a transmitting loop which is used for transmitting an electric energy signal through a transmitting coil; the plurality of receiving loops are used for receiving the electric energy signals; wherein each receiving loop comprises a receiving coil, a switched capacitor circuit and a rectifying circuit; the receiving coil receives the electric energy signal and then provides the electric energy signal to a load through the switched capacitor circuit and the rectifying circuit; and the switched capacitor signal circuit is connected with the switched capacitor circuit and is used for generating a switched capacitor control signal of the switched capacitor circuit based on the first phase information of the electric energy signal transmitted by the transmitting loop and the second phase information of the electric energy signal received by the receiving loop so as to carry out power distribution on the plurality of receiving loops.

Description

Technical Field

[0001] The present disclosure relates to the field of wireless power transmission, and in particular to a multi-load wireless power transmission system based on switched capacitor compensation. Background Art

[0002] In existing wireless power transmission technologies, the coil structure design has limitations in terms of load adaptability under different power requirements, and it is difficult to meet the requirements of flexible power distribution for multiple loads under complex working conditions. Although some methods of constructing equivalent impedance can alleviate the above problems to a certain extent, these methods usually require the introduction of additional components and circuits in the system topology, resulting in higher switching losses, which not only affects the efficiency of the system, but also increases the control complexity, limiting the flexibility and efficiency of the overall design. Summary of the invention

[0003] The present disclosure proposes a multi-load wireless power transmission system based on switched capacitor compensation to solve the above technical problems to a certain extent.

[0004] In a first aspect of the present disclosure, a multi-load wireless power transmission system based on switched capacitor compensation is provided, comprising:

[0005] A transmitting circuit, used for transmitting an electric energy signal via a transmitting coil;

[0006] A plurality of receiving circuits for receiving the electric energy signal; wherein each of the receiving circuits comprises a receiving coil, a switching capacitor circuit and a rectifying circuit; after the receiving coil receives the electric energy signal, the electric energy signal is provided to a load via the switching capacitor circuit and the rectifying circuit;

[0007] A switched capacitor signal circuit is connected to the switched capacitor circuit and is used to generate a switched capacitor control signal of the switched capacitor circuit based on the transmission phase information of the electric energy signal transmitted by the transmitting circuit and the reception phase information of the electric energy signal received by the receiving circuit, so as to compensate for the phase of the receiving coil current of the multiple receiving circuits, thereby realizing power distribution of the multiple receiving circuits.

[0008] From the above, it can be seen that the present disclosure provides a wireless power transmission system based on switched capacitor compensation, which adopts a switched capacitor circuit in the supplementary network of the receiving end to compensate for the current phase of each receiving coil. It can not only optimize the power distribution while compensating for the cross-coupling effect of the system, but also significantly simplify the design of the main circuit, reduce the number of required components, and simplify the control. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the present disclosure or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0010] Figure 1 Schematic diagram of a wireless power transmission system based on switched capacitor compensation according to an embodiment of the present disclosure.

[0011] Figure 2 This is an equivalent circuit of a wireless power transmission system based on switched capacitor compensation according to an embodiment of the present disclosure.

[0012] Figure 3A-3B 4 is a current vector diagram of a receiving coil of a wireless power transmission system based on switched capacitor compensation according to an embodiment of the present disclosure.

[0013] Figures 4A-4B 1 is a current vector diagram of a receiving coil under different compensation states of a wireless power transmission system based on switched capacitor compensation according to an embodiment of the present disclosure.

[0014] Figure 5 The figure is a working principle diagram of a wireless power transmission system based on switched capacitor compensation according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0015] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0016] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the embodiments of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0017] The output power of a wireless power transmission system depends not only on the load characteristics and coupling coefficient, but the power demand of the same load may also change significantly during operation. In this case, it will be difficult to achieve free and reliable access to electrical energy without an effective output power control mechanism. Therefore, in order to meet the fluctuations in load power demand at different time points, a precise output power control system must be implemented. This not only ensures that the system can provide stable power transmission under various working conditions, but also enhances the adaptability and reliability of the system, thereby promoting the practical application and development of wireless power transmission technology in more fields.

[0018] In the related technology, strategies for power distribution include coil structure, impedance matching, system control and other aspects. For example, in terms of coil structure, a strategy of arranging different numbers of receiving ends in the same plane can be adopted to ensure that each load can always obtain the same output power. The omnidirectional WPT system built on a rotating transmitter can provide uniform and synchronous power supply to multiple surrounding loads, but the system requires an additional motor drive to control the rotation of the transmitter. In terms of impedance matching, an equivalent impedance can be constructed through DC-DC converters, PWM controlled rectifiers, impedance inverters and other methods for power distribution. For example, power distribution control based on constant voltage output can be achieved by controlling the system input voltage and the receiving end DC-DC converter, and the equivalent impedance can be constructed by controlling the DC-DC circuit switching angle according to the load power demand. For another example, the phase angle difference between the input voltage fundamental wave and the input current fundamental wave of the PWM rectifier is The half-cycle angle of the input voltage 180°-2δ determines the equivalent input impedance Z L By controlling the on / off sequence and duration of the switch tube, different And δ, so that the equivalent input impedance ZL of the PWM rectifier meets the required impedance size. The equivalent input impedance of the PWM rectifier satisfies the following formula:

[0019]

[0020] For another example, impedance matching and power distribution are achieved by adding an impedance inverter circuit between the receiving coil and its load. Based on its ability to provide an input impedance characteristic that is inversely proportional to the load impedance, for a system with a single transmitter and a single receiver, when an impedance inverter is used, the impedance Z seen from the transmitter is 1 It can be expressed as K 11 is the characteristic impedance of the inverter, R L1 is the load resistance.

[0021] For another example, by adjusting the component values ​​in the inverter circuit (inductor L e and capacitor C e), the characteristic impedance K of the inverter can be changed e , and then adjust the external coupling coefficient k on the receiver side e , so as to achieve the required impedance matching condition. For example, in a multi-receiver system, the power distribution ratio received by different receivers can be controlled by adjusting the inverter on each receiver.

[0022] It is also possible to set the resonant frequencies of each receiving end to be different from each other, and apply excitations of different frequencies to the system, so as to construct a multi-frequency and multi-load WPT system. Power distribution between loads is achieved by controlling the frequency of the excitation source. Power distribution between loads can also be performed based on the idea of ​​time-division multiplexing. By continuously switching the compensation capacitor array at the transmitting end and applying excitations of the corresponding frequency, a single target load is powered at each moment, and the ratio of the output power of each load is equal to the ratio of the energy transmission time. A multi-frequency excitation source can also be constructed by superimposing multiple inverters with different frequencies.

[0023] In wireless transmission technology, the core purpose is to build a more uniform magnetic field environment by optimizing the coil arrangement strategy, designing the rotation characteristics of the coil structure, or realizing a rotating magnetic field. However, the traditional coil structure design has limitations in terms of load adaptability under different power requirements, and it is difficult to meet the requirements for load flexibility under complex working conditions. At the same time, these methods also show certain shortcomings in achieving effective power distribution. By adopting cascaded DC-DC converters, controllable PWM rectifiers, and impedance inverters to construct equivalent impedances, power distribution can be effectively achieved. However, these methods usually require the introduction of additional components and circuits in the system topology, which not only increases the complexity of the system, but also has relatively single functions, limiting the flexibility and efficiency of the overall design. In wireless power transmission (WPT) systems, although strategies such as frequency division, time division, and inverter superposition can achieve specific power transmission requirements, these methods are accompanied by significant challenges in practical applications. Specifically, such control strategies often lead to higher switching losses, which not only affects the efficiency of the system, but also increases the control complexity. In addition, the time-sharing transmission strategy usually requires additional configuration of capacitor arrays, while the inverter stacking solution requires the addition of additional inverter units, which undoubtedly increases the cost and design complexity of the overall system.

[0024] Therefore, how to improve the transmission power and transmission efficiency of wireless power transmission while optimizing power distribution, simplifying system structure, reducing costs, and improving system integration and efficiency has become a technical problem that needs to be solved urgently.

[0025] In view of this, the embodiment of the present disclosure provides a multi-load wireless power transmission system based on switched capacitor compensation. A switched capacitor circuit is used in the supplementary network at the receiving end to compensate for the current phase of the receiving coil. This not only optimizes power distribution while compensating for the cross-coupling effect of the system, but also significantly simplifies the design of the main circuit, reduces the number of required components, and simplifies control.

[0026] See also Figure 1 , Figure 1 A schematic diagram of a multi-load wireless power transmission system based on switched capacitor compensation according to an embodiment of the present disclosure is shown. Figure 1 In the invention, a multi-load wireless power transmission system based on switched capacitor compensation may include:

[0027] A transmitting circuit, used for transmitting an electric energy signal via a transmitting coil;

[0028] A plurality of receiving circuits for receiving the electric energy signal; wherein each of the receiving circuits comprises a receiving coil, a switching capacitor circuit and a rectifying circuit; after the receiving coil receives the electric energy signal, the electric energy signal is provided to a load via the switching capacitor circuit and the rectifying circuit;

[0029] A switched capacitor signal circuit is connected to the switched capacitor circuit and is used to generate a switched capacitor control signal of the switched capacitor circuit based on first phase information of the electric energy signal transmitted by the transmitting circuit and second phase information of the electric energy signal received by the receiving circuit, so as to compensate for the phase of the receiving coil current of the multiple receiving circuits, thereby realizing power distribution of the multiple receiving circuits.

[0030] Among them, when a control voltage or signal is applied to the switched capacitor, the capacitance value of the switched capacitor will change, thereby affecting the performance and characteristics of the circuit. By changing the frequency, amplitude or phase of the control signal, the capacitance value of the switched capacitor can be adjusted. The electric energy signal is transmitted through the transmitting circuit, and the receiving coils in multiple receiving circuits receive the electric energy signal, and the load is powered through the corresponding switched capacitor circuit and rectifier circuit. The system generates a switched capacitor control signal according to the phase information of the transmitted and received electric energy signals through the switched capacitor signal circuit to realize power distribution of multiple receiving circuits. This solution can effectively improve the efficiency and flexibility of the wireless power transmission system and ensure that each load obtains a stable power supply.

[0031] Specifically, the current phase of the receiving coil can be compensated through the switched capacitor circuit, and the compensation degree of each receiving circuit can be adjusted to change the phase relationship of the receiving coil current, thereby allocating power to each receiving circuit, reducing reactive power loss, and improving system output power.

[0032] In some embodiments, the switched capacitor signal circuit includes:

[0033] A phase time compensation module, used to determine a phase compensation value corresponding to the electric energy signal received by the receiving coil based on the transmitting phase information and the receiving phase information;

[0034] A power distribution module, connected to the phase time compensation module, and used to determine a compensation capacitance value required for compensation based on the phase compensation value;

[0035] The switch capacitor control signal generating module is connected to the power distribution module and is used to generate the switch capacitor control signal based on the compensation capacitance value.

[0036] Specifically, the equivalent circuit of the wireless power transmission system based on switched capacitor compensation is as follows: Figure 2 shown. Figure 2 In the equivalent circuit of the dual-load wireless power transmission system, the cross-coupling between the coils can be represented by a controllable voltage source. The influence of the two receiving coils on the transmitting coil loop can be represented by two controllable voltage sources. and The effect of the transmitting coil and the receiving coil 2 on the receiving coil 1 loop can be controlled by two controllable voltage sources. and The effect of the transmitting coil and the receiving coil 1 on the receiving coil 2 loop can be controlled by a controllable voltage source. and It can be concluded that both receiving coils 1 and 2 have two equivalent controllable voltage sources to provide power to the load. Among them, and With system parameter M 1 、M 2 ,I p The mutual inductance parameter of the system is affected by the position of the coil, and changing the current of the transmitting coil will change the overall transmission power of the system. Therefore, the controllable voltage source can be adjusted and The output power is changed by the size of the receiving coil. 12 It is related to the current of each loop. Therefore, the power distribution between the two receiving coils can be carried out by adjusting the degree of cross-coupling between the two coils and the current difference.

[0037] like Figure 2 As shown, Kirchhoff's voltage and current law is used to model the two-load WPT system, and the following relationship exists:

[0038]

[0039] Simplifying the system input current Primary coil current and the receiving end output current for:

[0040]

[0041] Where ω is the system operating frequency, is the input current of the transmitting circuit, U in is the input voltage of the transmitting circuit, is the transmitting coil current, is the current of the first receiving coil of the first receiving loop, is the current of the second receiving coil of the second receiving circuit, R p is the internal resistance of the transmitting coil, M 12 is the mutual inductance between the first receiving coil and the second receiving coil, L r is the self-inductance of the transmitting coil; M 1 is the mutual inductance between the transmitting coil and the first receiving coil, M 2 is the mutual inductance between the transmitting coil and the second receiving coil, R L1 is the load resistance of the first receiving circuit, R s1 is the internal resistance of the first receiving coil, R L2 is the load resistance of the second receiving circuit, R s2 is the internal resistance of the second receiving coil.

[0042] Under given conditions, the currents at receiving end 1 and receiving end 2 can be expressed as and The two are not in phase, and Compared to There is a phase advance angle θ. According to formula (2) and schematic Figure 1 By analyzing, the circuit phasor representation of the receiving end 1 can be constructed, such as Figure 3A As shown, the phase relationship between the two currents and Relative to The specific phase advance degree.

[0043] By analyzing Figure 3B Medium current phase relationship, controllable voltage source and current The phase difference is less than 90°, indicating that there is power flow between receiving coil 1 and receiving coil 2. Controllable voltage source The absorbed active power P_s1 and reactive power Q_s1 are:

[0044]

[0045] It can be seen from formula (3) that the controllable voltage source An inductive component and a resistive component are introduced into the loop of receiving coil 1. Among them, the inductive component introduced by the system cross-coupling effect causes the system reactive loss to increase and the system output power to decrease; while the active power flow direction of the two receiving coil loops is from the phase leading side to the phase lagging side.

[0046] In some embodiments, the receiving loop includes a first receiving loop and a second receiving loop, and the receiving phase information includes first receiving phase information of the first receiving loop and second receiving phase information of the second receiving loop;

[0047] The phase compensation module determines a phase compensation value corresponding to the electric energy signal received by the receiving coil based on the transmitting phase information and the receiving phase information, including:

[0048] Obtaining a first phase difference based on the transmit phase information and the first receive phase information, and obtaining a second phase difference based on the transmit phase information and the second receive phase information;

[0049] The phase compensation value is determined based on the first phase difference and the second phase difference.

[0050] Among them, in the wireless power transmission system, when the current phase of the receiving coil differs from the current phase of the transmitting coil by 90°, the system is in a completely resonant state. Therefore, the system can determine the current resonant state of the system based on the phase information of the two. Power allocation can be performed on this basis. For example, the current phase of the receiving coil 1 is greater than its phase at the resonance point, and the current phase of the receiving coil 2 is less than its phase at the resonance point, so that active power can flow from the receiving coil 1 to the receiving coil 2. The current phase information of the transmitting end can be used to establish a benchmark, and the phase difference is calculated by subtracting the time collected by the system from the system working cycle ratio. The phase reference value and the reference value of the resonance point can be determined by collecting the current phase of the transmitting coil. When making a comparison, the first phase difference (for example, the phase of the receiving coil 1-the phase of the transmitting coil) can be compared with the second phase difference (for example, the phase of the receiving coil 2-the phase of the transmitting coil).

[0051] Specifically, Figure 1-2 As shown, by adding a switched capacitor to the receiving coil loop to compensate for the inductive component of the system, the reactive power loss can be reduced and the system output power can be increased. Under the condition that the system output power is sufficient, the system output power can be distributed by adjusting the compensation degree of the two receiving coil loops to change the phase relationship of the two receiving coil currents. Figure 4A-4B As shown, it is the system vector diagram of the system under different compensation states. Figure 4A In the example, the current of receiving coil 1 is Phase leading the current of receiving coil 2 In phase θ, part of the active power of the receiving coil 1 loop flows to the receiving coil 2 loop; Figure 4B In the example, the current of receiving coil 2 is Phase leading the current of receiving coil 1 In phase θ, part of the active power in the receiving coil 2 circuit flows to the receiving coil 1 circuit.

[0052] In some embodiments, the phase compensation value includes:

[0053] ω is the system operating frequency, is the current of the first receiving coil of the first receiving loop, is the current of the second receiving coil of the second receiving loop, M 12 is the mutual inductance of the first receiving coil and the second receiving coil, P _s1 is the active power of the first receiving coil.

[0054] In some embodiments, the system further comprises:

[0055] A transmitting end current acquisition module, used to collect the transmitting coil current;

[0056] A first receiving end current acquisition module, used to acquire the current of the first receiving coil;

[0057] A second receiving end current acquisition module, used for acquiring the current of the second receiving coil;

[0058] A first receiving end voltage acquisition module, used for acquiring the voltage of the first receiving coil;

[0059] The phase time compensation module is also used to obtain the active power of the first receiving coil based on the current of the first receiving coil and the voltage of the first receiving coil; and determine the phase compensation value based on the active power, the current of the first receiving coil, the current of the second receiving coil, the system operating frequency, and the mutual inductance of the first receiving coil and the second receiving coil.

[0060] Among them, the current of the transmitting coil is detected in real time through the transmitting end current acquisition module, and the first receiving end current acquisition module and the second receiving end current acquisition module are responsible for acquiring the current in the first receiving coil and the second receiving coil respectively. For example, the transmitting end current acquisition module, the first receiving end current acquisition module and the second receiving end current acquisition module can be current sensors. The first receiving end voltage acquisition module acquires the voltage information of the first receiving coil. For example, the first receiving end voltage acquisition module can be a voltage sensor. The phase time compensation module can be based on the current and voltage data of the first receiving coil. The module can calculate the active power of the first receiving coil. And combined with the active power, the current of the first receiving coil, the current of the second receiving coil, the system operating frequency, and the mutual inductance of the first receiving coil and the second receiving coil, etc., the required phase compensation value is calculated to ensure that the system can maintain the best synchronization and transmission efficiency under different load and transmission conditions.

[0061] In some embodiments, the transmitting circuit further comprises:

[0062] An inverter module, used for converting a DC power signal into an AC signal;

[0063] A compensation topology module, connected to the inverter module, for compensating the AC signal to obtain the electric energy signal;

[0064] A transmitting coil is connected to the compensation topology module and is used to transmit the electric energy signal.

[0065] Among them, in the wireless power transmission system, since the coupling transformer composed of the transmitting coil and the receiving coil requires an AC signal to effectively transmit electrical energy, the inverter converts the stable DC power into AC power of the required frequency through the internal oscillator and other circuit elements. The compensation topology module is connected to the inverter module to compensate the AC signal to obtain an electrical energy signal suitable for transmission. The compensation topology module can enhance the flexibility of output voltage regulation, improve system efficiency, and ensure that the output voltage does not change with the load. The transmitting coil is connected to the compensation topology module to transmit the compensated electrical energy signal. When the AC signal passes through the transmitting coil, it generates a magnetic field in the surrounding space, which is then captured by the receiving coil and converted into electrical energy.

[0066] In some embodiments, the transmitting circuit further comprises:

[0067] A transmitting end phase information acquisition module, connected between the compensation topology module and the transmitting coil, and used for acquiring the transmitting phase information of the electric energy signal transmitted by the transmitting coil;

[0068] The transmitting end communication module is connected to the transmitting end phase information acquisition module and is used to send the transmitting phase information to the receiving end.

[0069] Among them, when the transmitting coil starts to transmit the electric energy signal, the transmitting end phase information acquisition module monitors and collects the phase information of the transmitted electric energy signal in real time. The transmitting end communication module can send it to the receiving end by wire or wireless means. After the receiving end receives the phase information, it is used for subsequent tasks such as synchronization control and power allocation. The phase information acquisition module can collect the phase information of AC signals or other periodic signals. For example, it can be connected to the signal source through the internal sensor interface to collect the phase information of the signal in real time.

[0070] In some embodiments, the receiving circuit further comprises:

[0071] A receiving end phase information acquisition module, connected between the receiving coil and the switched capacitor circuit, for acquiring receiving phase information of the electric energy signal received by the receiving coil, and sending the receiving phase information to the switched capacitor signal circuit;

[0072] The receiving end communication module is used to receive the transmission phase information from the transmission loop; and send the transmission phase information to the switched capacitor signal circuit.

[0073] Among them, the phase information acquisition module at the transmitting end and the phase information acquisition module at the receiving end detect the zero-crossing moment of the current through the zero-crossing detection module, and subtract different current zero-crossing moments to obtain the phase information. The phase information acquisition module in the transmitting circuit first collects the transmitting phase information of the electric energy signal emitted by the transmitting coil, and then sends it to the receiving end through the transmitting communication module. At the same time, the phase information acquisition module at the receiving end also collects the receiving phase information of the electric energy signal received by the receiving coil in real time. After receiving the transmitting phase information, the receiving end communication module sends it together with the locally collected receiving phase information to the switched capacitor signal circuit. The phase compensation module of the switched capacitor signal circuit determines the corresponding phase compensation value based on these phase information, and makes power allocation decisions to optimize the transmission efficiency and stability of the system.

[0074] In some embodiments, the transmitting end communication module and the receiving end communication module communicate with each other in a wireless communication manner. For example, the transmitting end communication module and the receiving end communication module may be Bluetooth modules.

[0075] Combination Figure 1 and Figure 5First, the system transmitting coil current and its phase can be collected and sent to the receiving coil loop through the Bluetooth module; at the same time, the receiving coil loop collects the current of the receiving coil and its phase relationship, as well as the voltage of the receiving coil. The current phase of the receiving coil can also be compared through the Bluetooth module. Because there is a time error between the current phase of the receiving end and the current phase of the transmitting end during the collection and transmission process, the system can first compensate the phase information collected by the transmitting end and the receiving end through the phase time compensation module. When fully compensated, the actual compensated phase difference can be consistent with the theoretical value (i.e., the phase compensation value). Then, the target capacitance value corresponding to the phase compensation value is calculated through the power distribution module; finally, the PWM control signal of the switch tube in the switched capacitor circuit is generated according to the capacitance value through the switched capacitor control signal generation module, and the equivalent capacitance value of the switched capacitor circuit is adjusted to the target capacitance value to achieve the power distribution of the system.

[0076] It can be seen that the multi-load wireless power transmission system based on switched capacitor compensation according to the embodiment of the present disclosure can achieve decoupling and power distribution at the same time by simply adjusting the size of the switched capacitor; the control variable parameters are few, the main circuit of the system is simple, and the control is simple. While improving the transmission power and transmission efficiency of wireless power transmission, it can optimize power distribution, simplify the system structure, reduce costs, and improve the integration and efficiency of the system.

[0077] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. Based on the concept of the present disclosure, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present disclosure as described above, which are not provided in detail for the sake of simplicity.

[0078] In addition, to simplify the description and discussion, and in order not to make the embodiments of the present disclosure difficult to understand, the known power / ground connections to the integrated circuit (IC) chips and other components may or may not be shown in the provided figures. In addition, the device can be shown in the form of a block diagram to avoid making the embodiments of the present disclosure difficult to understand, and this also takes into account the fact that the details of the implementation of these block diagram devices are highly dependent on the platform on which the embodiments of the present disclosure will be implemented (that is, these details should be fully within the scope of understanding of those skilled in the art). Where specific details (e.g., circuits) are set forth to describe exemplary embodiments of the present disclosure, it is apparent to those skilled in the art that the embodiments of the present disclosure can be implemented without these specific details or with changes in these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0079] Although the present disclosure has been described in conjunction with specific embodiments of the present disclosure, many replacements, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.

[0080] The embodiments of the present disclosure are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A multi-load wireless power transmission system based on switched capacitor compensation, characterized in that: include: A transmitting circuit, used for transmitting an electric energy signal via a transmitting coil; A plurality of receiving circuits for receiving the electric energy signal; wherein each of the receiving circuits comprises a receiving coil, a switching capacitor circuit and a rectifying circuit; after the receiving coil receives the electric energy signal, the electric energy signal is provided to a load via the switching capacitor circuit and the rectifying circuit; A switched capacitor signal circuit is connected to the switched capacitor circuit and is used to generate a switched capacitor control signal of the switched capacitor circuit based on the transmission phase information of the electric energy signal transmitted by the transmitting circuit and the reception phase information of the electric energy signal received by the receiving circuit, so as to compensate for the phase of the receiving coil current of the multiple receiving circuits, thereby realizing power distribution of the multiple receiving circuits.

2. The system according to claim 1, characterized in that The switched capacitor signal circuit comprises: A phase time compensation module, used to determine a phase compensation value corresponding to the electric energy signal received by the receiving coil based on the transmitting phase information and the receiving phase information; A power distribution module, connected to the phase time compensation module, and used to determine a compensation capacitance value required for compensation based on the phase compensation value; The switch capacitor control signal generating module is connected to the power distribution module and is used to generate the switch capacitor control signal based on the compensation capacitance value.

3. The system according to claim 2, characterized in that The receiving circuit includes a first receiving circuit and a second receiving circuit, and the receiving phase information includes first receiving phase information of the first receiving circuit and second receiving phase information of the second receiving circuit; The phase compensation module determines a phase compensation value corresponding to the electric energy signal received by the receiving coil based on the transmitting phase information and the receiving phase information, including: Obtaining a first phase difference based on the transmit phase information and the first receive phase information, and obtaining a second phase difference based on the transmit phase information and the second receive phase information; The phase compensation value is determined based on the first phase difference and the second phase difference.

4. The system according to claim 3, characterized in that The phase compensation value includes: ω is the system operating frequency, is the current of the first receiving coil of the first receiving loop, is the current of the second receiving coil of the second receiving loop, M 12 is the mutual inductance of the first receiving coil and the second receiving coil, P _s1 is the active power of the first receiving coil.

5. The system according to claim 1, characterized in that The equivalent model of the multi-load wireless power transmission system includes: Where ω is the system operating frequency, is the input current of the transmitting circuit, U in is the input voltage of the transmitting circuit, is the transmitting coil current, is the current of the first receiving coil of the first receiving loop, is the current of the second receiving coil of the second receiving circuit, R p is the internal resistance of the transmitting coil, M 12 is the mutual inductance between the first receiving coil and the second receiving coil, L r is the self-inductance of the transmitting coil; M1 is the mutual inductance between the transmitting coil and the first receiving coil, M2 is the mutual inductance between the transmitting coil and the second receiving coil, R L1 is the load resistance of the first receiving circuit, R s1 is the internal resistance of the first receiving coil, R L2 is the load resistance of the second receiving circuit, R s2 is the internal resistance of the second receiving coil.

6. The system according to claim 1, characterized in that The transmitting circuit also includes: An inverter module, used for converting a DC power signal into an AC signal; A compensation topology module, connected to the inverter module, for compensating the AC signal to obtain the electric energy signal; A transmitting coil is connected to the compensation topology module and is used to transmit the electric energy signal.

7. The system according to claim 6, characterized in that The transmitting circuit also includes: A transmitting end phase information acquisition module, connected between the compensation topology module and the transmitting coil, and used for acquiring the transmitting phase information of the electric energy signal transmitted by the transmitting coil; The transmitting end communication module is connected to the transmitting end phase information acquisition module and is used to send the transmitting phase information to the receiving end.

8. The system according to claim 7, characterized in that The receiving circuit also includes: A receiving end phase information acquisition module, connected between the receiving coil and the switched capacitor circuit, for acquiring receiving phase information of the electric energy signal received by the receiving coil, and sending the receiving phase information to the switched capacitor signal circuit; The receiving end communication module is used to receive the transmission phase information from the transmission loop; and send the transmission phase information to the switched capacitor signal circuit.

9. The system according to claim 8, characterized in that The transmitting end communication module and the receiving end communication module communicate with each other in a wireless communication manner.

10. The system according to claim 4, characterized in that Also includes: A transmitting end current acquisition module, used to collect the transmitting coil current; A first receiving end current acquisition module, used to acquire the current of the first receiving coil; A second receiving end current acquisition module, used for acquiring the current of the second receiving coil; A first receiving end voltage acquisition module, used for acquiring the voltage of the first receiving coil; The phase time compensation module is further used to obtain the active power of the first receiving coil based on the current of the first receiving coil and the voltage of the first receiving coil; And the phase compensation value is determined based on the active power, the current of the first receiving coil, the current of the second receiving coil, the system operating frequency, and the mutual inductance of the first receiving coil and the second receiving coil.

Images