A comprehensive vector shielding wireless power transmission system based on phase-locked loop

Abstract

The application provides a comprehensive vector shielding wireless power transmission system based on a phase-locked loop, which comprises a direct-current power supply, an inverter circuit, a transmitting coil, a resonance capacitor, a receiving coil, a load, a phase-locked loop, a shielding coil and a rectifier circuit; the inverter circuit 1 is connected with the direct-current power supply 1, the G pole of the MOS tube S1 in the inverter circuit 1 is connected with the phase-locked loop 1, the D pole of the MOS tube S4 is connected with the transmitting coil L1, and the S pole of the MOS tube S1 is connected with the phase-locked loop 2 and the resonance capacitor C1 respectively; the inverter circuit 2 is connected with the direct-current power supply 2. The application has the beneficial effects that: for the problem that the wireless power transmission system has a large magnetic leakage during the transmission process and influences the external environment, the application can accurately shield the reverse magnetic leakage through the shielding circuit, so that the magnetic leakage level is always below the international standard; when the wireless charging system has a large system magnetic leakage caused by the change of the coupling value, the application can also automatically adjust and accurately shield the magnetic leakage.

Description

Technical Field

[0001] This invention belongs to the field of wireless power transmission, and in particular relates to a comprehensive vector shielded wireless power transmission system based on a phase-locked loop. Background Technology

[0002] Currently, most shielding structures in wireless power transmission systems only use magnetic conductors or passive coils for magnetic leakage shielding. However, using only magnetic conductors can only guide the magnetic flux into the power transmission circuit as much as possible, which inevitably leads to excessive magnetic leakage on the back and sides of the transmitting coil of the wireless power transmission system. Furthermore, when the coupling coefficient between the transmitting and receiving ends of the wireless power transmission system changes, the above two methods and structures cannot accurately reduce the magnetic leakage on the sides and back of the system. Summary of the Invention

[0003] In view of this, the present invention aims to propose a comprehensive vector shielded wireless power transfer system based on a phase-locked loop (PLL). Existing wireless power transfer systems suffer from problems such as inaccurate leakage flux cancellation and the inability to accurately cancel leakage flux after changes in the coupling coefficient. This invention designs a comprehensive vector shielded wireless power transfer system based on a PLL to reduce leakage flux generated during the operation of the wireless power transfer system.

[0004] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0005] A phase-locked loop-based integrated vector shielded wireless power transmission system includes a DC power supply, an inverter circuit, a transmitting coil, a resonant capacitor, a receiving coil, a load, a phase-locked loop, a shielding coil, and a rectifier circuit.

[0006] Inverter circuit 1 is connected to DC power supply 1. In inverter circuit 1, the gate of MOSFET S1 is connected to phase-locked loop 1, the drain of MOSFET S4 is connected to the transmitting coil L1, and the source of MOSFET S1 is connected to phase-locked loop 2 and resonant capacitor C1 respectively.

[0007] Inverter circuit 2 is connected to DC power supply 2. In inverter circuit 2, the source of MOSFET Q1 is connected to the shielding coil LS, and the gate of MOSFET Q4 is connected to phase-locked loop 2.

[0008] The receiving coil is connected to the resonant capacitor C2 and the rectifier circuit is connected to the load.

[0009] Furthermore, when the wireless power transmission system is operating normally, phase-locked loops 1 and 2 are in a locked state.

[0010] Furthermore, the equivalent circuit is a shielded coil, which is made in a double-D pattern and is bent using the flexible and foldable characteristics of copper foil to complete vector shielding.

[0011] Furthermore, when the coupling coefficient changes due to abnormal operating conditions such as offset, phase-locked loop 1 comes into play, adjusting the S1 and S2 drive signals to keep the phase of the transmitter current and the transmitter voltage consistent. At the same time, phase-locked loop 2 also comes into play, adjusting the phase of the transmitter current and the shield current by adjusting the Q1 and Q2 drive signals.

[0012] Compared with existing technologies, the integrated vector shielded wireless power transmission system based on phase-locked loop described in this invention has the following advantages:

[0013] The present invention discloses a comprehensive vector shielded wireless power transmission system based on a phase-locked loop. This system addresses the problem of large magnetic leakage during wireless power transmission, which affects the external environment. The patent uses a shielding circuit to perform precise reverse magnetic leakage shielding, keeping the magnetic leakage level below international standards. Even if the system's magnetic leakage increases due to changes in coupling value in the wireless charging system, it can automatically adjust and perform precise magnetic leakage shielding. Attached Figure Description

[0014] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0015] Figure 1 This is a schematic diagram of the equivalent circuit of the wireless power transmission system and the vector shielded coil described in an embodiment of the present invention.

[0016] Figure 2 This is a spatial diagram showing the transmitting coil and shielding coil of the wireless power transmission system described in an embodiment of the present invention.

[0017] Figure 3 This is a cross-sectional view of the wireless power transmission transmitting coil and shielding coil described in an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures:

[0019] 1-DC power supply 1; 2-Inverter circuit 1; 3-Transmitter; 4-Resonant capacitor 1; 5-Transmitter coil; 6-Receiver; 7-Resonant capacitor 2; 8-Receiver coil; 9-Load; 10-Phase-locked loop 1; 11-Phase-locked loop 2; 12-DC power supply 2; 13-Inverter circuit 2; 14-Shielding terminal; 15-Shielding coil; 16-Resonant capacitor 3; 17-Rectifier circuit. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0021] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] The main problem this patent aims to solve is that existing wireless power transfer systems suffer from inaccurate leakage magnetic flux cancellation and the inability to accurately cancel leakage magnetic flux after changes in the coupling coefficient. A phase-locked loop-based integrated vector shielded wireless power transfer system is designed to reduce leakage magnetic flux generated during operation.

[0023] When the wireless power transmission system is operating normally, phase-locked loops 1 and 2 are in a locked state and do not function. The shielding coil is made of copper foil. Figure 2 As shown, the equivalent circuit is (15) coil. The shielding coil is made in a double D style. The flexible and foldable characteristics of copper foil are used to bend it to complete the vector shielding. At this time, the magnetic field generated by the current flowing through the copper foil is opposite to the magnetic field generated by the main circuit transmitting coil, thus completing the shielding of the system leakage magnetic field. When the coupling coefficient changes due to abnormal operating conditions such as offset, the phase-locked loop 1 plays a role. By adjusting the S1 and S2 driving signals, the phase of the transmitting end current and the phase of the transmitting end voltage are kept in the same phase. At the same time, the phase-locked loop 2 also plays a role. By adjusting the Q1 and Q2 driving signals, the phase of the transmitting end current and the phase of the shielding end current are kept in the same phase. In the physical space, the transmitting coil and the shielding coil are placed in opposite directions to complete the precise shielding of the system leakage magnetic field after the system operating conditions change.

[0024] When the system is working normally, phase-locked loops 11 and 10 do not function and are in a locked state. Parts 10 and 11 do not work. However, at this time, the drive signal on the gate (G) of S1 in the circuit where DC1 is located is collected by the phase-locked loop. At the same time, the voltage signal on C1 in the main circuit is also collected by the phase-locked loop. The phase difference is compared. If there is no phase angle difference, the phase-locked loop does not work. If there is a phase angle difference, the gate (G) drive signal of the inverter bridge MOSFET is adjusted so that the phase of the drive voltage is forced to be consistent with the phase of the C1 branch, and the adjusted MOSFET drive signal is output. S1 and S4 are in-phase drive signals, and S2 and S3 are in-phase drive signals (the lying triangle and circle are inverters used to output in-phase signals). Q1234 is the same as S1234. The signal collected by phase-locked loop 10 on C1 is filtered out by a zero-crossing comparator to obtain the phase information.

[0025] When the system deviates, after the phase-locked loop 10 operates according to the above process, the phase-locked loop 11 will also play a role. The signal it collects is the gate drive signal of Q4 of the MOSFET in the C1 branch and the DC2 circuit. By comparing their signals, the phase of the drive voltage signal of Q4 is adjusted so that the phase of the current ILS in the DC2 circuit is opposite to the phase of IC1. At this time, the magnetic field generated by the current flowing through the copper foil is opposite to the magnetic field generated by the main circuit transmitting coil, thus completing the shielding of system leakage magnetic field.

[0026] Those skilled in the art will recognize that the units and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0027] In the several embodiments provided in this application, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the division of units described above is merely a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. The aforementioned units may or may not be physically separated. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention according to actual needs.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A comprehensive vector shielded wireless power transfer system based on phase-locked loop, characterized in that: The DC power supply, the inverter circuit, the transmitting coil, the resonance capacitor, the receiving coil, the load, the phase-locked loop, the shielding coil and the rectifier circuit are included. The inverter circuit 1 is connected with the DC power supply 1, the G pole of the MOS tube S1 in the inverter circuit 1 is connected with the phase-locked loop 1, the D pole of the MOS tube S4 is connected with the transmitting coil L1, and the S pole of the MOS tube S1 is connected with the phase-locked loop 2 and the resonance capacitor C1 respectively. The inverter circuit 2 is connected with the DC power supply 2, the S pole of the MOS tube Q1 in the inverter circuit 2 is connected with the shielding coil LS, and the G pole of the MOS tube Q4 is connected with the phase-locked loop 2. The receiving coil is connected with the resonance capacitor C2, and the rectifier circuit is connected with the load. DC1 is a direct current power supply, outputting direct current voltage, positive pole connecting the drain of MOS tube S1 and S3, negative pole connecting the source of MOS tube S2 and S4; MOS tube S1, S2, S3, S4, constituting H bridge structure, compensation capacitor C1 one end connecting the source of MOS tube S1 and the drain of S2, C1 other end connecting transmitting coil L1 one end, L1 other end connecting the source of S3 and the drain of S4, receiving coil L2 one end connecting compensation capacitor C2, other end connecting rectification module alternating current input first end, C2 other end connecting rectification module alternating current input second end, load R L two ends connecting the direct current output end of rectification module respectively; DC2 is a direct current power supply, outputting direct current voltage, the positive pole connecting the drain of MOS tubes Q1 and Q3, and the negative pole connecting the source of MOS tubes Q2 and Q4; MOS tubes Q1, Q2, Q3 and Q4 constitute an H-bridge structure, and capacitor C s One end is connected with the source of MOS tube Q1 and the drain of Q2, and the other end is connected with shield coil L s , L s The other end is connected with the source of Q3 and the drain of Q4; The phase-locked loop 1 (10) controls the phase of the main loop current through the zero-crossing comparison module, and generates the driving signals S1-S4 at the output end, which are fed back to the gate of the transmission circuit H bridge (2); the phase-locked loop 2 (11) controls the phase of the branch current, and generates the driving signals Q1-Q4 at the output end, which are fed back to the gate of the shielding circuit H bridge (13); When the system generates a coupling coefficient change due to abnormal operation states such as deviation, the phase-locked loop 1 plays a role, adjusts the S1 and S2 driving signals, so that the phase of the transmitting end current and the transmitting end voltage remains consistent, at the same time, the phase-locked loop 2 also plays a role, adjusts the Q1 and Q2 driving signals, and adjusts the phase of the transmitting end current and the shielding end current to be consistent. When the wireless power transmission system is in normal operation, the phase-locked loop 1 and the phase-locked loop 2 are in a latching state.

2. The PLL-based integrated vector shielding wireless power transfer system of claim 1, wherein: The shielding coil is made in a double-D pattern, which is bent by taking advantage of the flexible and foldable characteristics of copper foil, and the vector shielding is completed.

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