Load wireless electric energy transmission system with constant current output

Abstract

The invention discloses a load wireless electric energy transmission system with constant current output, which belongs to the technical field of wireless electric energy transmission, and comprises a transmitting device and a receiving device, and is characterized in that the transmitting device comprises an alternating current controlled current source, a transmitting end control module and a transmitting module; the receiving device comprises a receiving module, a control signal generation module and a load; the output end of the AC controlled current source is connected with the transmitting module, and the input end is connected with the transmitting end control module; the receiving module is connected in series with the load; the control signal generation module is connected in parallel between the receiving module and the load; the transmitting device and the receiving device complete electric energy transmission and signal transmission through mutual inductance. On the premise that complex closed-loop control and a preceding-stage DC-DC conversion structure are not introduced, the wireless electric energy transmission system which is insensitive to load characteristics and coupling coefficient changes and has the constant-current output capacity is achieved.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission technology, and more specifically to a load wireless power transmission system with constant current output. Background Technology

[0002] Wireless power transfer technology, compared to traditional wired power supply, offers advantages such as flexibility, convenience, safety, and reliability due to the absence of electrical connections. In practical applications, maintaining a constant system output current is often required. A typical approach is to introduce closed-loop negative feedback control by adding a pre-converter on the primary side or a Buck or Boost type DC-DC converter on the secondary side. While this achieves good results, it increases control complexity and reduces stability. Another common method is based on a compensation network design, leveraging the topology's inherent constant current output characteristics to achieve constant current output to the load without complex closed-loop negative feedback control. However, the system's constant current output performance is extremely sensitive to the mutual inductance of the coupling mechanism, thus limiting its effectiveness. Furthermore, existing constant current control technologies primarily target purely resistive loads, exhibiting poor applicability to inductive and capacitive loads. This invention achieves constant output current control by adjusting the current across the load to be in phase or out of phase with the output current of the controlled AC current source. The output current is unaffected by load size or changes in coupling coefficient and load characteristics. The system exhibits excellent constant current output characteristics, and the overall system control is simple, offering significant advantages in practical applications. Summary of the Invention

[0003] In view of the above-mentioned problems, the present invention is proposed.

[0004] Therefore, the technical problem solved by this invention is: how to realize a wireless power transmission system that is insensitive to changes in load characteristics and coupling coefficients and has constant current output capability without introducing complex closed-loop control and front-end DC-DC conversion structure.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a load wireless power transmission system with constant current output, comprising, wherein the transmitting device includes an AC controlled current source, a transmitting end control module, and a transmitting module;

[0006] The receiving device includes a receiving module, a control signal generation module, and a load;

[0007] The output of the AC controlled current source is connected to the transmitting module, and the input is connected to the transmitting control module.

[0008] The receiving module is connected in series with the load, and the control signal generation module is connected in parallel between the receiving module and the load;

[0009] The transmitting and receiving devices transmit electrical energy and signals through mutual inductance.

[0010] As a preferred embodiment of the load wireless power transmission system with constant current output described in this invention, the transmitter control module includes a drive control signal receiving module and a switch drive module.

[0011] As a preferred embodiment of the load wireless power transmission system with constant current output described in this invention, the control signal generation module includes an output current sampling module, a drive control signal conditioning module, and a drive control signal transmission module.

[0012] In a preferred embodiment of the load wireless power transmission system with constant current output described in this invention, the drive control signal receiving module receives signals emitted by the drive control signal transmitting module, and the output terminal of the drive control signal receiving module is connected to the input terminal of the switch drive module.

[0013] As a preferred embodiment of the load wireless power transmission system with constant current output described in this invention, the output terminal of the switch drive module is connected to the control input terminal of the AC controlled current source, and a switch drive signal is generated according to the drive control signal to control the output current of the AC controlled current source.

[0014] As a preferred embodiment of the load wireless power transmission system with constant current output described in this invention, the receiving module consists of a receiving coil, a receiving end resonant capacitor, and an equivalent internal resistance of the receiving coil connected in series.

[0015] The transmitting module consists of a receiving coil, a receiving end resonant capacitor, and the equivalent internal resistance of the receiving coil connected in series.

[0016] As a preferred embodiment of the load wireless power transmission system with constant current output described in this invention, wherein: the input terminal of the output current sampling module is connected to the load to sample the phase of the output current;

[0017] The output terminal of the output current sampling module is connected to the input terminal of the drive control signal conditioning module.

[0018] The advantages of this preferred technical solution are: by sampling the phase of the load output current, the system can determine whether the current energy transmission is in the optimal resonance state based on the phase deviation, providing highly sensitive feedback information for the subsequent control signal conditioning module. Compared with the traditional method of sampling voltage or current amplitude, it has stronger response capability and dynamic adaptability.

[0019] As a preferred embodiment of the load wireless power transmission system with constant current output described in this invention, the drive control signal conditioning module generates a square wave drive control signal that is in the same direction or opposite to the output current based on the phase of the sampled transmission current.

[0020] The advantages of this preferred technical solution are as follows: By sampling the output current phase in real time, the drive control signal conditioning module can accurately determine whether the current system is operating in the target state where the input current and output current are in phase or opposite. Based on this criterion, it generates a square wave drive control signal that is in the same or opposite direction as the output current, thus realizing a transmitter frequency regulation control strategy based on phase synchronization determination. This method eliminates the need for traditional voltage / current closed-loop regulation modules and does not rely on complex front-end DC-DC or compensation networks, thereby significantly simplifying the system structure and enhancing the adaptability to changes in load impedance, coupling coefficient, and other factors while maintaining control accuracy.

[0021] In a preferred embodiment of the load wireless power transmission system with constant current output described in this invention, the output terminal of the drive control signal conditioning circuit is connected to the input terminal of the drive control signal transmitting module.

[0022] In a preferred embodiment of the load wireless power transmission system with constant current output described in this invention, the drive control signal transmitting module sends the drive control signal to the drive control signal receiving module.

[0023] The present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, characterized in that the processor executes the computer program to implement the steps of the aforementioned load wireless power transmission system with constant current output.

[0024] The present invention provides a computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the steps of a load wireless power transmission system with constant current output.

[0025] The beneficial effects of this invention are as follows: This invention determines whether the system is in a stable operating state based on the current phase relationship. Compared with the traditional method of adjusting by current amplitude feedback, this method is independent of load size or impedance type, has a faster response speed, and can maintain a stable output current even for capacitive or inductive loads. The entire system control logic is concentrated at the transmitting end, and the receiving end does not need to connect a DC-DC converter or additional adjustment module, resulting in a simpler structure, a clearer control path, and less likelihood of system divergence or local control conflicts. The control signal is sent from the receiving end and then fed back to the transmitting end to adjust the current source. The energy channel and the control channel are separate. The advantage of this is that even if the positions between the coils shift and the energy transmission efficiency decreases, the control chain will not be broken, and the system can continuously maintain a stable output current. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a structural diagram of a load wireless power transfer system with constant current output provided in one embodiment of the present invention.

[0028] Figure 2 An equivalent circuit diagram of a load wireless power transfer system with constant current output is provided as an embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram illustrating the effect of a load wireless power transmission system with constant current output provided in one embodiment of the present invention. Detailed Implementation

[0030] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0031] Example 1, referring to Figure 1 This is one embodiment of the present invention, which provides a load wireless power transmission system with constant current output, including: a transmitting device and a receiving device;

[0032] The transmitting device includes an AC controlled current source, a transmitter control module, and a transmitting module;

[0033] The receiving device includes a receiving module, a control signal generation module, and a load;

[0034] The output of the AC controlled current source is connected to the transmitting module, and the input is connected to the transmitting control module.

[0035] The receiving module is connected in series with the load, and the control signal generation module is connected in parallel between the receiving module and the load;

[0036] The transmitting and receiving devices transmit electrical energy and signals through mutual inductance.

[0037] In existing wireless power transfer systems, achieving constant current output typically relies on adding a DC-DC converter at the receiver or constructing voltage and current amplitude feedback loops at the transmitter to adjust output parameters. While these solutions can cope with load variations to some extent, they also introduce higher control complexity and regulation delays. Especially in applications where load characteristics change rapidly or coupling states are unstable, the system is prone to output fluctuations or control instability.

[0038] This embodiment employs a control method based on current phase criterion. Instead of relying on the output current or voltage amplitude as a feedback reference, it determines whether the system is in a stable operating state by sampling the phase information of the output current on the load side. The sampled phase signal is conditioned to generate a control signal, which is fed back from the receiver to the transmitter via an information transmission device to adjust the output power of the AC controlled current source. This control method effectively avoids the response delay problem in the amplitude feedback path and simplifies the receiver structure, avoiding the introduction of an additional power regulation module.

[0039] Furthermore, the control signal and energy transmission path are structurally decoupled, ensuring the control closed loop remains effective even under conditions such as fluctuations in mutual inductance or coil position misalignment. This enhances the system's stability and adaptability in dynamic operating environments. The overall control path of this topology is clear, and the adjustment link converges quickly, making it suitable for compact wireless power supply applications with high response requirements.

[0040] Example 2, refer to Figure 1 As an embodiment of the present invention, a load wireless power transfer system with constant current output is provided based on the previous embodiment, comprising:

[0041] Reference Figure 1 The transmitter control module includes a drive control signal receiving module and a switch drive module.

[0042] The control signal generation module includes an output current sampling module, a drive control signal conditioning module, and a drive control signal transmission module.

[0043] The drive control signal receiving module receives signals from the drive control signal transmitting module, and the output of the drive control signal receiving module is connected to the input of the switch drive module.

[0044] The output of the switch drive module is connected to the control input of the AC controlled current source, and generates a switch drive signal based on the drive control signal to control the output current of the AC controlled current source.

[0045] The receiving module consists of a receiving coil connected in series, a resonant capacitor at the receiving end, and the equivalent internal resistance of the receiving coil.

[0046] The transmitting module consists of a receiving coil, a receiving end resonant capacitor, and the equivalent internal resistance of the receiving coil, all connected in series.

[0047] The input terminal of the output current sampling module is connected to the load to sample the phase of the output current.

[0048] The output terminal of the output current sampling module is connected to the input terminal of the drive control signal conditioning module.

[0049] The drive control signal conditioning module generates a square wave drive control signal that is in the same direction or opposite to the output current based on the phase of the sampled transmission current.

[0050] The output of the drive control signal conditioning circuit is connected to the input of the drive control signal transmitting module.

[0051] The drive control signal transmitting module sends the drive control signal to the drive control signal receiving module.

[0052] The load can be any type of load.

[0053] The output current of the AC controlled current source is either in phase or out of phase with the current across the load, meaning the input current of the transmitting module is either in phase or out of phase with the output current of the receiving module, satisfying the following equation:

[0054]

[0055] in, It is the difference between the phase angle of the input current and the phase angle of the output current. These are the input current phase angle and the output current phase angle, respectively. The system is said to meet the constant current output requirement only when the phase difference between the input and output currents satisfies the above equation.

[0056] The natural frequency of the transmitting module is the same as the natural frequency of the receiving module, that is, satisfying: ω1=ω2, where, This indicates the inherent frequency of the transmitting module's circuit. L1 represents the natural frequency of the receiving module circuit, L2 represents the inductance of the transmitting coil, and C1 represents the resonant capacitance of the transmitting end, while C2 represents the resonant capacitance of the receiving end.

[0057] Example 3, referring to Figure 2 As one embodiment of the present invention, a load wireless power transfer system with constant current output is provided.

[0058] S1. The AC controlled current source, under the regulation of the transmitting end control module, converts the voltage signal V... i The series circuit applied to the transmitting module, this series circuit is through the impedance formed by the coil inductance L1 and the capacitor C1. Then, the resonant current can be obtained at the inductor of the transmitting end.

[0059] S2, resonant current An alternating magnetic field is generated at the transmitting coil, which couples with the receiving coil to induce an electromotive force at the receiving coil. Figure 1 The impedance at the receiving module can be obtained as follows: By circuit Figure 1 According to Kirchhoff's voltage law, the load voltage is:

[0060]

[0061] S3. When electrical energy is conducted from the transmitter to the receiver, the receiver module is connected in series with the load, and the current at the load is... When the current When the current flows to the current sampling module, the current sampling module collects the phase information of the current for subsequent control decisions; refer to Figure 2 From Kirchhoff's voltage law, we can obtain:

[0062]

[0063] S4. After receiving the current sampling signal from the current sampling module, the drive control signal conditioning module analyzes the current signal. If the phase relationship is found to not satisfy the constant current condition (i.e., the imaginary part is not zero), that is, the difference between the phase angles of the input current and the output current is not 0 or π, then...

[0064]

[0065] Based on this, set the imaginary part of the above equation to zero and solve for the result. Then, regenerate the drive control signal that is in the same or opposite direction as the output current based on the result.

[0066] S5. The drive control signal is transmitted to the transmitter via the drive control signal transmitting module to ensure that the signal feedback process is not interrupted and the closed-loop control path is maintained.

[0067] S6. The drive control signal receiving module of the transmitting end receives the feedback signal and hands it over to the switch drive module for processing. The system is tuned by adjusting the output frequency ω or current amplitude I1 of the AC controlled current source.

[0068] S7. After the system enters a new resonant state, if the condition ω1=ω2 is satisfied, then... and In-phase or out-of-phase, thus maintaining a constant output current, as shown by the formula:

[0069]

[0070] The derived frequency operating point enables stable control closed loop.

[0071] Example 4, refer to Figures 2-3 As one embodiment of the present invention, a load wireless power transfer system with constant current output is provided.

[0072] To verify the beneficial effects of this invention, scientific demonstration was conducted through experiments.

[0073] Reference Figure 2 This is the equivalent schematic diagram of the system. Figure 2 We can obtain:

[0074]

[0075] in, These represent the input voltage vector of the transmitting module and the output voltage vector across the load, respectively. These are the current vectors of the transmitting and receiving circuits, respectively, Z. L Z1 = jωL1 + 1 / jωC1 is the load impedance, Z2 = jωL2 + 1 / jωC2 is the receiver module circuit impedance; ω is the system operating frequency, L1 is the inductance of the transmitting coil, L2 is the inductance of the receiving coil; C1 is the resonant capacitance of the transmitting end, C2 is the resonant capacitance of the receiving end; M is the mutual inductance between the transmitting coil and the receiving coil.

[0076] According to equation (1), the ratio of input voltage to output voltage is:

[0077]

[0078] Setting the imaginary part of equation (2) to zero, i.e., the input current and output current are in phase or out of phase, we can obtain the system operating frequency as:

[0079]

[0080] For simplicity, let R1 = R2 = 0 and L1C1 = L2C2, then we can obtain:

[0081]

[0082] Substituting equation (4) into equation (2), we get:

[0083]

[0084] in, is the coupling coefficient between the transmitting coil and the receiving coil, and M is the mutual inductance between the transmitting coil in the transmitting module and the receiving coil in the receiving module.

[0085] As can be seen from equation (5), when the input current is fixed, the output current remains constant and is independent of the load size, load characteristics and coupling coefficient.

[0086] Reference Figure 3 The graph shows the relationship between the ratio of system input current to output current and the coupling coefficient under different load types. As can be seen from the graph, the output current does not change with the coupling coefficient, regardless of whether it is a purely resistive load or an inductive load, and it has good constant current characteristics.

[0087] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A load wireless power transfer system with constant current output, characterized in that: Includes a transmitting device and a receiving device; The transmitting device includes an AC controlled current source, a transmitter control module, and a transmitting module; The receiving device includes a receiving module, a control signal generation module, and a load; The output of the AC controlled current source is connected to the transmitting module, and the input is connected to the transmitting control module. The receiving module is connected in series with the load, and the control signal generation module is connected in parallel between the receiving module and the load; The transmitting and receiving devices complete the transmission of electrical energy and signals through mutual inductance.

2. The load wireless power transfer system with constant current output as described in claim 1, characterized in that: The transmitter control module includes a drive control signal receiving module and a switch drive module.

3. A load wireless power transfer system with constant current output as described in claim 2, characterized in that: The control signal generation module includes an output current sampling module, a drive control signal conditioning module, and a drive control signal transmission module.

4. A load wireless power transfer system with constant current output as described in claim 3, characterized in that: The drive control signal receiving module receives signals from the drive control signal transmitting module, and the output terminal of the drive control signal receiving module is connected to the input terminal of the switch drive module.

5. A load wireless power transfer system with constant current output as described in claim 4, characterized in that: The output terminal of the switch drive module is connected to the control input terminal of the AC controlled current source, and generates a switch drive signal according to the drive control signal to control the output current of the AC controlled current source.

6. A load wireless power transfer system with constant current output as described in claim 5, characterized in that: The receiving module consists of a receiving coil, a receiving end resonant capacitor, and the equivalent internal resistance of the receiving coil connected in series. The transmitting module consists of a receiving coil, a receiving end resonant capacitor, and the equivalent internal resistance of the receiving coil connected in series.

7. A load wireless power transfer system with constant current output as described in claim 6, characterized in that: The input terminal of the output current sampling module is connected to the load to sample the phase of the output current; The output terminal of the output current sampling module is connected to the input terminal of the drive control signal conditioning module.

8. A load wireless power transfer system with constant current output as described in claim 7, characterized in that: The drive control signal conditioning module generates a square wave drive control signal that is in the same direction or opposite to the output current based on the sampled transmission current phase.

9. A load wireless power transfer system with constant current output as described in claim 8, characterized in that: The output of the drive control signal conditioning circuit is connected to the input of the drive control signal transmitting module.

10. A load wireless power transfer system with constant current output as described in claim 9, characterized in that: The drive control signal transmitting module sends the drive control signal to the drive control signal receiving module.

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