High-offset immunity characteristics of a loosely coupled transformer and control method

Abstract

The application discloses a high anti-deviation characteristic loosely coupled transformer and a control method. The transformer comprises a transmitting coil, a receiving coil, a first inverter circuit, a second inverter circuit, a first compensation network, a second compensation network, a third compensation network and a fourth compensation network. The transmitting coil comprises a first transmitting winding and a second transmitting winding. The first transmitting winding is formed with a first magnetic induction line through hole and a fourth magnetic induction line through hole. The second transmitting winding is formed with a second magnetic induction line through hole and a third magnetic induction line through hole. The first magnetic induction line through hole to the fourth magnetic induction line through hole are arranged in a cross shape. The first transmitting winding is connected to the output end of the first inverter circuit through the first compensation network. The second transmitting winding is connected to the output end of the second inverter circuit through the second compensation network. The receiving coil comprises a first receiving winding and a second receiving winding arranged orthogonally. The first receiving winding is connected to the input end of the third compensation network. The second receiving winding is connected to the input end of the fourth compensation network. The technical scheme of the application has the advantages of simple structure, easy control and strong anti-deviation capability.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission technology, and in particular to a loosely coupled transformer with high anti-offset characteristics and a control method thereof. Background Technology

[0002] Inductive wireless power transfer (IPT) systems enable contactless power transfer through magnetic field coupling. With their advantages of high power transfer flexibility, strong environmental adaptability, safety, convenience, and aesthetics, they have been widely used in underwater equipment power supply, consumer electronics charging, and electric vehicle charging.

[0003] However, in inductive wireless power transfer systems, when the transmitting or receiving coils are offset, the coupling coefficient decreases and the system parameters change, which leads to problems such as reduced system efficiency, power fluctuations, and reduced system stability. Existing solutions to the offset problem require the addition of closed-loop control or the use of hybrid compensation networks, which results in excessive system complexity and control difficulty. Summary of the Invention

[0004] The main objective of this invention is to provide a loosely coupled transformer with high anti-offset characteristics, aiming to solve the problems of excessive system complexity and control difficulty caused by existing technical solutions for offset issues.

[0005] To achieve the above objectives, the present invention proposes a high-offset-resistance loosely coupled transformer for use in a wireless power transmission system. The wireless power transmission system includes a DC power supply, a first inverter circuit, a second inverter circuit, a first compensation network, a second compensation network, a third compensation network, a fourth compensation network, and a rectifier circuit. The input terminals of the first and second inverter circuits are respectively connected to the DC power supply. The output terminals of the third and fourth compensation networks are respectively connected to the input terminals of the rectifier circuit. The output terminal of the rectifier circuit is connected to the load. The high-offset-resistance loosely coupled transformer includes:

[0006] The transmitting coil includes a first transmitting winding and a second transmitting winding. The first transmitting winding has a first magnetic field line through-hole and a fourth magnetic field line through-hole, and the second transmitting winding has a second magnetic field line through-hole and a third magnetic field line through-hole. The first magnetic field line through-hole, the second magnetic field line through-hole, the third magnetic field line through-hole and the fourth magnetic field line through-hole are arranged in a grid pattern. The first transmitting winding is connected to the output terminal of the first inverter circuit via the first compensation network, and the second transmitting winding is connected to the output terminal of the second inverter circuit via the second compensation network.

[0007] The receiving coil includes a first receiving winding and a second receiving winding arranged orthogonally. The first receiving winding is connected to the input terminal of the third compensation network, and the second receiving winding is connected to the input terminal of the fourth compensation network.

[0008] Optionally, the first transmitting winding forms the first magnetic field line through-hole and the fourth magnetic field line through-hole arranged diagonally.

[0009] The first transmitting winding is used to control the direction of the magnetic field lines passing through the first magnetic field line through-hole and the fourth magnetic field line through-hole according to the AC current output after compensation by the first compensation network.

[0010] Optionally, when the first transmitting winding is connected to the AC current output after compensation by the first compensation network, the magnetic field lines passing through the first magnetic field line through-hole and the fourth magnetic field line through-hole are in opposite directions.

[0011] Optionally, the second transmitting winding forms the second magnetic field line through-hole and the third magnetic field line through-hole arranged diagonally;

[0012] The second transmitting winding is used to control the direction of the magnetic field lines passing through the second magnetic field line through-hole and the third magnetic field line through-hole according to the AC current output by the second inverter circuit.

[0013] Optionally, when the second transmitting winding is connected to the AC current output after compensation by the second compensation network, the magnetic field lines passing through the second magnetic field line through-hole and the third magnetic field line through-hole are in opposite directions.

[0014] Optionally, the conductive coils on the first transmitting winding and the second transmitting winding are wound in a figure-eight pattern.

[0015] Optionally, the first receiving winding and the second receiving winding are orthogonally stacked to form a first channel, a second channel, a third channel, and a fourth channel that pass through the receiving coil and are arranged in a grid pattern.

[0016] Optionally, the first receiving winding includes an interconnected first winding portion and a second winding portion, wherein the first winding portion forms a fifth magnetic field line through-hole, and the second winding portion forms a sixth magnetic field line through-hole.

[0017] The second receiving winding includes an interconnected third winding portion and a fourth winding portion, wherein the third winding portion forms a seventh magnetic field line through-hole and the fourth winding portion forms an eighth magnetic field line through-hole.

[0018] A portion of the fifth magnetic field line through-hole and a portion of the seventh magnetic field line through-hole are connected to form the first channel, and another portion of the fifth magnetic field line through-hole and a portion of the eighth magnetic field line through-hole are connected to form the third channel;

[0019] A portion of the sixth magnetic field line through-hole and another portion of the seventh magnetic field line through-hole are connected to form the second channel, and another portion of the sixth magnetic field line through-hole and another portion of the eighth magnetic field line through-hole are connected to form the fourth channel.

[0020] This invention also proposes a control method for a loosely coupled transformer with high offset resistance, applied to a wireless power transmission system. The wireless power transmission system includes a DC power supply, a first inverter circuit, a second inverter circuit, a first compensation network, a second compensation network, a third compensation network, a fourth compensation network, a rectifier circuit, and a loosely coupled transformer with high offset resistance as described above. The input terminals of the first and second inverter circuits are respectively connected to the DC power supply. The output terminal of the first inverter circuit is connected to the first transmitting winding of the loosely coupled transformer with high offset resistance via the first compensation network. The output terminal of the second inverter circuit is connected to the second transmitting winding of the loosely coupled transformer with high offset resistance via the second compensation network. The input terminal of the third compensation network is connected to the first receiving winding of the loosely coupled transformer with high offset resistance. The input terminal of the fourth compensation network is connected to the second receiving winding of the loosely coupled transformer with high offset resistance. The output terminals of the third and fourth compensation networks are respectively connected to the input terminals of the rectifier circuit. The output terminal of the rectifier circuit is connected to the load. The control method for the loosely coupled transformer with high offset resistance includes:

[0021] Determine whether the transmitting and receiving coils in a loosely coupled transformer with high offset resistance are offset;

[0022] When it is determined that the transmitting and receiving coils of a loosely coupled transformer with high anti-offset characteristics are offset, the offset direction of the transmitting and receiving coils is determined.

[0023] Based on the determined offset direction, the phase difference between the outputs of the first inverter circuit and the second inverter circuit is controlled.

[0024] Optionally, the high-offset-resistance loosely coupled transformer control method further includes:

[0025] Before controlling the high offset resistance loosely coupled transformer to transmit electrical energy, the phase of the first inverter circuit is controlled to be a first preset phase, and the phase of the second inverter circuit is controlled to be a second preset phase.

[0026] Wherein, the difference between the first preset phase and the second preset phase is not less than 0° and not greater than 180°.

[0027] This invention addresses the issue by connecting the first and second transmitting windings of the transmitting coil to AC current output from an inverter circuit. This ensures that the direction of the magnetic field emitted by the transmitting coil is the vector sum of the magnetic fields generated by the first and second transmitting windings, with the magnetic fields determined by the phase of the AC current. Therefore, when the transmitting and receiving coils experience relative misalignment, the phase difference between the first and second inverter circuits can be controlled to alter the magnetic field emitted by the transmitting coil. This allows either the first or second receiving winding to still generate AC current based on the altered magnetic field, achieving stable power transmission and maintaining stable efficiency and power fluctuations in the wireless power transmission system. Compared to existing solutions that involve adding closed-loop control or hybrid compensation networks, this invention eliminates the need for dedicated closed-loop feedback circuits and feedback control algorithms, and simplifies the control logic by requiring only the current direction of the first and second inverter circuits. This overcomes the problems of excessive system complexity and control difficulty inherent in existing solutions for misalignment. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of a structure of an embodiment of the loosely coupled transformer with high anti-displacement characteristics of the present invention;

[0030] Figure 2 This is a schematic diagram of the receiving coil in one embodiment of the high offset resistance loosely coupled transformer of the present invention;

[0031] Figure 3 This is a schematic diagram showing the direction of the magnetic field lines through which the transmitting coil passes in one embodiment of the high offset resistance loosely coupled transformer of the present invention;

[0032] Figure 4 This is a schematic diagram showing the direction of the magnetic field lines traversed by the transmitting coil in another embodiment of the loosely coupled transformer with high anti-offset characteristics of the present invention;

[0033] Figure 5 This is a schematic diagram of the wireless transmission system used in an embodiment of the high offset resistance loosely coupled transformer of the present invention;

[0034] Figure 6This is a flowchart illustrating the steps of an embodiment of the loosely coupled transformer control method with high anti-offset characteristics according to the present invention.

[0035] Explanation of icon numbers:

[0036]

[0037] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described 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 the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0040] This invention proposes a loosely coupled transformer with high anti-offset characteristics.

[0041] Currently, the common methods to address the misalignment between the transmitting and receiving coils of a transformer are to add closed-loop control to the wireless power transmission system or to use a hybrid compensation network. However, adding closed-loop control, such as adjusting the operating frequency of the inverter circuit and tracking the resonant frequency after parameter changes, undoubtedly increases the complexity of the system and the corresponding control costs. On the other hand, using a hybrid compensation network utilizes the complementary characteristics of different compensation networks when parameters deviate to achieve stable output, but this approach undoubtedly increases the control difficulty, size, and cost of the system.

[0042] To solve the above problems, refer to Figures 1 to 2 The high offset resistance loosely coupled transformer includes a transmitting coil and a receiving coil;

[0043] The transmitting coil includes a first transmitting winding L1 and a second transmitting winding L2. The first transmitting winding L1 and the second transmitting winding L2 form a first magnetic field line through hole S1, a second magnetic field line through hole S2, a third magnetic field line through hole S3 and a fourth magnetic field line through hole S4 arranged in a grid pattern.

[0044] The receiving coil includes a first receiving winding A1 and a second receiving winding A2 arranged orthogonally. The first receiving winding A1 is connected to the input terminal of the third compensation network 60, and the second receiving winding A2 is connected to the input terminal of the fourth compensation network 70.

[0045] A loosely coupled transformer with high anti-offset characteristics can be applied to a wireless power transmission system. The wireless power transmission reverse system may include a DC power supply 10, a first inverter circuit 20, a second inverter circuit 30, a first compensation network 40, a second compensation network 50, a third compensation network 60, a fourth compensation network 70, and a rectifier circuit 80. The input terminals of the first inverter circuit 20 and the second inverter circuit 30 can be connected to the DC power supply 10, respectively. The output terminals of the third compensation network 60 and the fourth compensation network 70 are connected to the input terminals of the rectifier circuit 80, respectively. The output terminal of the rectifier circuit 80 is connected to the load 90. The first inverter circuit 20 is used to convert the DC voltage output from the DC power supply 10 into AC voltage and output it to the first compensation network 40 for compensation. The second inverter circuit 30 is used to convert the DC voltage output from the DC power supply 10 into AC voltage and output it to the second compensation network 50 for compensation. The rectifier circuit 80 is used to stabilize the AC voltage output after compensation by the third compensation network 60 or the fourth compensation network 70, convert it into DC voltage, and output it to the load 90 to supply power to the load 90.

[0046] In this embodiment, the transmitting coil may include a first transmitting winding L1 and a second transmitting winding L2 that are independent of each other and insulated from each other. The winding method of the first transmitting winding L1 and the second transmitting winding L2 can be designed so that each of the first transmitting winding L1 and the second transmitting winding L2 can form two rectangular magnetic field lines through holes, namely, the first magnetic field line through hole S1 to the fourth magnetic field line through hole S4. The four magnetic field line through holes (S1 to S4) can be arranged in a grid pattern, that is, the first magnetic field line through hole S1 and the fourth magnetic field line through hole S4 can be diagonally opposite each other, and the second magnetic field line through hole S2 and the third magnetic field line through hole S3 can be diagonally opposite each other; alternatively, the first magnetic field line through hole S1 and the fourth magnetic field line through hole S4 can be located in the same row or column, and the second magnetic field line through hole S2 and the third magnetic field line through hole S3 can be located in another row or column.

[0047] When the first transmitting winding L1 outputs an AC voltage after being compensated by the first compensation network 40, it can form magnetic field lines passing through the first magnetic field line through-hole S1 and the fourth magnetic field line through-hole S4 under the excitation of the AC voltage. The direction of the magnetic field lines passing through the first magnetic field line through-hole S1 and the fourth magnetic field line through-hole S4 can be reversed by the winding method of the first transmitting winding L1. When the second transmitting winding L2 outputs an AC voltage after being compensated by the second compensation network 50, it can form magnetic field lines passing through the second magnetic field line through-hole S2 and the third magnetic field line through-hole S3 under the excitation of the AC voltage. The direction of the magnetic field lines passing through the second magnetic field line through-hole S2 and the third magnetic field line through-hole S3 can be reversed by the winding method of the second transmitting winding L2.

[0048] The receiving coil may include a first receiving winding A1 and a second receiving winding A2, which are independent and insulated from each other. The first receiving winding A1 and the second receiving winding A2 may be orthogonally arranged, that is, perpendicular to each other. When the first receiving winding A1 or the second receiving winding A2 receives the magnetic field lines emitted by the transmitting coil, it can induce a corresponding alternating current and output it to the third compensation network 60 or the fourth compensation network 70. After being compensated by the third compensation network 60 or the fourth compensation network 70, the current is output to the rectifier circuit 80 to power the downstream load 90, thereby realizing the wireless transmission of electrical energy. It can be understood that since the first receiving winding A1 and the second receiving winding A2 are orthogonally arranged, when the receiving coil receives electrical energy, only one of the two receiving windings, the first receiving winding A1 and the second receiving winding A2, will work and induce an alternating current, which will be output to the downstream third compensation network 60 or the fourth compensation network 70, while the other will not work.

[0049] It is understood that the direction of the magnetic field emitted by the transmitting coil in the high-offset-resistance loosely coupled transformer of the present invention is the vector sum of the magnetic fields generated by the first transmitting winding L1 and the second transmitting winding L2, and the magnetic fields generated by the first transmitting winding L1 and the second transmitting winding L2 are determined by the phase of the AC current connected to them. Therefore, when the transmitting coil and the receiving coil are offset in a certain direction, the phase difference between the first inverter circuit 20 and the second inverter circuit 30 can be controlled according to the offset direction to change the magnetic field emitted by the transmitting coil, so that the first receiving winding A1 or the second receiving winding A2 can still generate AC current induced by the changed magnetic field, thereby achieving stable power transmission, and thus keeping the efficiency and power fluctuations of the wireless power transmission system stable. Compared to existing technical solutions that use closed-loop control or hybrid compensation networks, this method eliminates the need for designing dedicated closed-loop feedback circuits and feedback control algorithms, as well as hybrid compensation networks. It only requires controlling the current direction of the first inverter circuit 20 and the second inverter circuit 30, resulting in simple control logic. This solves the problems of excessive system complexity and control difficulty caused by existing technical solutions for offset issues.

[0050] Reference Figures 1 to 2 The first transmitting winding L1 forms a first magnetic field line through hole S1 and a fourth magnetic field line through hole S4 arranged diagonally. The first transmitting winding L1 is used to control the direction of the magnetic field lines passing through the first magnetic field line through hole S1 and the fourth magnetic field line through hole S4 according to the AC current output after compensation by the first compensation network 40.

[0051] When the first transmitting winding L1 is connected to the AC current output after compensation by the first compensation network 40, the magnetic field lines passing through the first magnetic field line through hole S1 and the fourth magnetic field line through hole S4 are in opposite directions.

[0052] Optionally, the second transmitting winding L2 forms the second magnetic field line through-hole S2 and the third magnetic field line through-hole S3 arranged diagonally; the second transmitting winding L2 is used to control the direction of the magnetic field lines passing through the second magnetic field line through-hole S2 and the third magnetic field line through-hole S3 according to the AC current output by the second inverter circuit 30.

[0053] When the second transmitting winding L2 is connected to the AC current output by the second inverter circuit 30, the magnetic field lines passing through the second magnetic field line through hole S2 and the third magnetic field line through hole S3 are in opposite directions.

[0054] In this embodiment, both the first transmitting winding L1 and the second transmitting winding L2 may include two diagonally arranged rectangular ring coils and two connecting segments. It is understood that the through-hole in each rectangular ring coil can be a magnetic field line through-hole. In either the first transmitting winding L1 or the second transmitting winding L2, a notch may be provided at one corner opposite to each other. The notch of one rectangular ring coil can be connected to the notch of the other rectangular ring coil through the two connecting segments. The first transmitting winding L1 and the second transmitting winding L2 may be orthogonally placed, that is, any connecting segment in the first transmitting winding L1 may be perpendicular to any connecting segment in the second transmitting winding L2, thereby enabling the first transmitting winding L1 to form a diagonally arranged first magnetic field line through-hole S1 and a fourth magnetic field line through-hole S4, and enabling the second transmitting winding L2 to form a diagonally arranged second magnetic field line through-hole S2 and a third magnetic field line through-hole S3.

[0055] The first transmitting winding L1 can be wound using an "8"-shaped winding method to form a conductive coil, so that when the first transmitting winding L1 receives the AC output after compensation by the first compensation network 40, it generates a magnetic field passing through the first magnetic field line through hole S1 and the fourth magnetic field line through hole S4. At this time, the direction of the magnetic field lines passing through the first magnetic field line through hole S1 and the fourth magnetic field line through hole S4 can correspond to the AC output direction of the first compensation network 40. The first compensation network 40 can include a first output terminal and a second output terminal. The first transmitting winding L1 can be connected to the first output terminal and the second output terminal of the first compensation network 40 respectively. Therefore, the current output direction of the first compensation network 40 can be divided into two opposite directions: from the first output terminal through the first transmitting winding L1 to the second output terminal and from the second output terminal through the first transmitting winding L1 to the first output terminal. Of course, regardless of the direction of the current output by the first compensation network 40, the directions of the magnetic field lines passing through the first magnetic field line through hole S1 and the fourth magnetic field line through hole S4 are opposite. Specifically, the magnetic field lines passing through one of the first magnetic field line through hole S1 and the fourth magnetic field line through hole S4 enter from the plane where the first transmitting winding L1 is located, while the magnetic field lines passing through the other are set to exit from the plane where the first transmitting winding L1 is located.

[0056] The second transmitting winding L2 can also be wound using an "8"-shaped winding method to form the conductive coil, so that when the second transmitting winding L2 receives the AC output after compensation by the second compensation network 50, it generates a magnetic field passing through the second magnetic field line through hole S2 and the third magnetic field line through hole S3. At this time, the direction of the magnetic field lines passing through the second magnetic field line through hole S2 and the third magnetic field line through hole S3 can correspond to the AC output direction of the second compensation network 50. The second compensation network 50 can include a first output terminal and a second output terminal. The second transmitting winding L2 can be connected to the first output terminal and the second output terminal of the second compensation network 50 respectively. Therefore, the current output direction of the first compensation network 40 can be divided into two opposite directions: from the first output terminal through the second transmitting winding L2 to the second output terminal and from the second output terminal through the second transmitting winding L2 to the first output terminal. Of course, regardless of the direction of the current output by the second compensation network 50, the directions of the magnetic field lines passing through the second magnetic field line through-hole S2 and the third magnetic field line through-hole S3 are opposite. Specifically, the magnetic field lines passing through one of the second magnetic field line through-hole S2 and the third magnetic field line through-hole S3 enter from the plane where the second transmitting winding L2 is located, while the magnetic field lines passing through the other pass out from the plane where the second transmitting winding L2 is located.

[0057] In this way, the directions of the magnetic field lines passing through the four magnetic field lines from the first magnetic field line through-hole S1 to the fourth magnetic field line through-hole S4 can form multiple combinations, thereby forming multiple magnetic field directions of the transmitting coil, which is beneficial to meet the adjustment requirements of the magnetic field of the transmitting coil after the transmitting coil and the receiving coil are offset.

[0058] Reference Figures 1 to 2 The first receiving winding A1 and the second receiving winding A2 are orthogonally stacked to form a first through hole P1, a second through hole P2, a third through hole P3 and a fourth through hole P4 arranged in a grid pattern, penetrating the receiving coil.

[0059] The first receiving winding A1 and the second receiving winding A2 may include multiple interconnected winding portions. Each winding portion may have at least one magnetic field line through-hole. When the first receiving winding A1 and the second receiving winding A2 are orthogonally stacked, some of the magnetic field line through-holes in the first receiving winding A1 and the second receiving winding A2 may be connected to form four channels arranged in a grid pattern through the receiving coil, namely the first channel to the fourth channel (P1 to P4).

[0060] Specifically, the first receiving winding A1 and the second receiving winding A2 can be disposed on two adjacent planes, and the orthogonal overlapping of the first receiving winding A1 and the second receiving winding A2 can be achieved by making each winding portion in the first receiving winding A1 perpendicular to each winding portion in the second receiving winding A2; or by making each winding portion in the second receiving winding A2 perpendicular to each winding portion in the first receiving winding A1.

[0061] Optionally, both the first receiving winding A1 and the second receiving winding A2 have two winding portions. The first receiving winding A1 includes an interconnected first winding portion A11 and a second winding portion A12. The first winding portion A11 forms a fifth magnetic field line through-hole S5, and the second winding portion A12 forms a sixth magnetic field line through-hole S6. The second receiving winding A2 includes a third winding portion A21 and a fourth winding portion A22. The third winding portion A21 forms a seventh magnetic field line through-hole S7, and the fourth winding portion A22 forms an eighth magnetic field line through-hole S8. It should be noted that the interconnection relationship between the first winding portion A11 and the second winding portion A12, and the interconnection relationship between the third winding portion A21 and the fourth winding portion A22, are... Figure 2 It is not shown in the text.

[0062] The first winding portion A11 or the second winding portion A12 is flush with the sides of the third winding portion A21 and the fourth winding portion A22 in the second preset direction D2, respectively, on both sides of the first winding portion A21 or the fourth winding portion A22 in the first preset direction D1, respectively, on both sides of the first winding portion A11 and the second winding portion A12 in the second preset direction D2; wherein, the first preset direction D1 can be its length direction, the second preset direction D2 can be its width direction, and the first preset direction D1 and the second preset direction D2 are perpendicular to each other. It should be noted that the first preset direction D1 and the second preset direction D2 of the first winding section A11 are the same as those of the second winding section A12, and the first preset direction D1 and the second preset direction D2 of the third winding section A21 are the same as those of the fourth winding section A22. However, the first preset direction D1 and the second preset direction D2 corresponding to each winding section in the first receiving winding A1 are different from those corresponding to each winding section in the second receiving winding A2. For details, please refer to [reference needed]. Figure 4 Specifically, the first preset direction D1 corresponding to each winding portion in the first receiving winding A1 is the same as the second preset direction D2 corresponding to each winding portion in the second receiving winding A2, and the second preset direction D2 corresponding to each winding portion in the first receiving winding A1 is the same as the first preset direction D1 corresponding to each winding portion in the second receiving winding A2.

[0063] The first winding portion A11 to the fourth winding portion A22 can all be rectangular rings, and can have a first side and a second side opposite to each other in the first preset direction D1, and a third side and a fourth side opposite to each other in the second preset direction D2; it should be noted that the third side can be a side away from another winding portion in the same receiving winding, and the fourth side can be a side close to another winding portion in the same receiving winding.

[0064] In this embodiment, the first side A111 of the first winding portion A11 is flush with the third side A213 of the third winding portion A21, the second side A112 of the first winding portion A11 is flush with the third side A223 of the fourth winding portion A22, and the third side A113 of the first winding portion A11 is flush with the first side A211 of the third winding portion A21 and the first side A221 of the fourth winding portion A22; the first side A121 of the second winding portion A12 is flush with the third side A213 of the third winding portion A21, the second side A122 of the second winding portion A12 is flush with the third side A223 of the fourth winding portion A22, and the third side A123 of the second winding portion A12 is flush with the second side A212 of the third winding portion A21 and the second side A222 of the fourth winding portion A22.

[0065] The first side A211 of the third winding portion A21 is flush with the third side A113 of the first winding portion A11, the second side A212 of the third winding portion A21 is flush with the third side A123 of the second winding portion A12, and the third side A213 of the third winding portion A21 is flush with the first side A111 of the first winding portion A11 and the first side A121 of the second winding portion A12; the first side A221 of the fourth winding portion A22 is flush with the third side A113 of the first winding portion A11, the second side A222 of the fourth winding portion A22 is flush with the third side A123 of the second winding portion A12, and the third side A223 of the fourth winding portion A22 is flush with the second side A112 of the first winding portion A11 and the second side A122 of the second winding portion A12.

[0066] Optionally, the fifth magnetic field line through-hole S5 and the sixth magnetic field line through-hole S6 may have a first part magnetic induction through-hole and a second part magnetic induction through-hole that are opposite each other in the first preset direction D1; the seventh magnetic field line through-hole S7 and the eighth magnetic field line through-hole S8 may have a first part magnetic induction through-hole and a second part magnetic induction through-hole that are opposite each other in the second preset direction D2. When the first receiving winding A1 and the second receiving winding A2 are orthogonally stacked, the first part of the magnetic induction through-hole of the fifth magnetic field line through-hole S5 can be connected with the first part of the magnetic induction through-hole of the seventh magnetic field line through-hole S7 to form a first channel P1; the second part of the magnetic induction through-hole of the fifth magnetic field line through-hole S5 can be connected with the first part of the magnetic induction through-hole of the eighth magnetic field line through-hole S8 to form a second channel P2; the first part of the magnetic induction through-hole of the sixth magnetic field line through-hole S6 can be connected with the second part of the magnetic induction through-hole of the seventh magnetic field line through-hole S7 to form a third channel P3; and the second part of the magnetic induction through-hole of the sixth magnetic field line through-hole S6 can be connected with the second part of the magnetic induction through-hole of the eighth magnetic field line through-hole S8 to form a fourth channel P4.

[0067] Furthermore, since the transmitting and receiving coils of the high-offset-resistance loosely coupled transformer of the present invention have different structures, the offset resistance performance is better than that of transmitting and receiving coils with the same structure. Moreover, experiments have shown that by selecting the transmitting and receiving coil structures disclosed in the present invention, a transformer structure with even better offset resistance performance can be obtained based on the selection of different coil structures.

[0068] This invention also proposes a control method for loosely coupled transformers with high anti-offset characteristics, which can be applied to wireless power transmission systems.

[0069] Reference Figure 5 The wireless power transmission inverter system includes a DC power supply 10, a first inverter circuit 20, a second inverter circuit 30, a first compensation network 40, a second compensation network 50, a third compensation network 60, a fourth compensation network 70, and a rectifier circuit 80, as well as a high-offset-resistance loosely coupled transformer as described above. The specific structure of this high-offset-resistance loosely coupled transformer is as described in the above embodiments. Since this high-offset-resistance loosely coupled transformer control method adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be elaborated further here.

[0070] The input terminals of the first inverter circuit 20 and the second inverter circuit 30 are respectively connected to the DC power supply 10. The output terminal of the first inverter circuit 20 is connected to the first transmitting winding L1 of the high offset resistance loosely coupled transformer via the first compensation network 40. The output terminal of the second inverter circuit 30 is connected to the second transmitting winding L2 of the high offset resistance loosely coupled transformer via the second compensation network 50. The input terminal of the third compensation network 60 is connected to the first receiving winding A1 of the high offset resistance loosely coupled transformer. The input terminal of the fourth compensation network 70 is connected to the second receiving winding A2 of the high offset resistance loosely coupled transformer. The output terminals of the third compensation network 60 and the fourth compensation network 70 are respectively connected to the input terminal of the rectifier circuit 80. The output terminal of the rectifier circuit 80 is connected to the load 90.

[0071] The first inverter circuit 20 and the second inverter circuit 30 convert the DC voltage output from the DC power supply 10 into AC voltage, respectively, and output it to the first compensation network 40 and the second compensation network 50. After compensation by the first compensation network 40 and the second compensation network 50, the AC voltage is output to the first transmitting winding L1 and the second transmitting winding L2 of the high-offset-resistance loosely coupled transformer, thereby driving the transmitting coil of the high-offset-resistance loosely coupled transformer to transmit electrical energy to the receiving coil. The receiving coil of the high-offset-resistance loosely coupled transformer can convert the received electrical energy into AC voltage and output it to the third compensation network 60 or the fourth compensation network 70. After compensation by the third compensation network 60 or the fourth compensation network 70, the AC voltage is output to the rectifier circuit 80, and after rectification by the rectifier current, it is converted into DC voltage and output to the load 90 to power the load 90. This achieves wireless transmission of electrical energy.

[0072] In this embodiment, the wireless power transmission system may also include a control device. This control device can be used to control the operation of the first inverter circuit 20 and the second inverter circuit 30, and to control the phase of the AC current output by the first inverter circuit 20 and the second inverter circuit 30 when they are operating. This control device can serve as the execution subject of the high-offset-resistance loosely coupled transformer control method of the present invention. Of course, in other embodiments, the execution subject for implementing the high-offset-resistance loosely coupled transformer control method of the present application may also be another control device independent of the control devices for the first inverter circuit 20 and the second inverter circuit 30. The two can be communicatively connected to achieve direction control of the AC current output by the first inverter circuit 20 and the second inverter circuit 30. The following embodiments use the example where the control device for controlling the operation of the first inverter circuit 20 and the second inverter circuit 30 is the same control device as the control device for implementing the control method of the present invention, to explain the implementation steps of the high-offset-resistance loosely coupled transformer control method of the present application.

[0073] Reference Figures 1 to 6 The high-offset-resistance loosely coupled transformer control method includes:

[0074] Step S100: Determine whether the transmitting coil and receiving coil in the high offset resistance loosely coupled transformer have been offset;

[0075] Step S200: When it is determined that the transmitting coil and receiving coil of the high offset resistance loosely coupled transformer are offset, determine the offset direction of the transmitting coil and receiving coil;

[0076] Step S300: Control the phase difference between the first inverter circuit 20 and the second inverter circuit 30 according to the determined offset direction.

[0077] In this embodiment, the control device can wirelessly connect to the device where the receiving coil is located via a wireless communication module to obtain the relative position information output by the device. Alternatively, the control device can also be electrically connected to a dedicated position detection module to receive the position detection signal output by the position detection module after detecting the position of the receiving coil or its device. Based on the received relative position information or position detection signal, the control device can determine whether the real-time relative position of the transmitting coil and the receiving coil matches a preset relative position, and can determine whether the relative position of the transmitting coil and the receiving coil has shifted based on the matching result.

[0078] Specifically, when the matching result shows that the real-time relative position matches the preset relative position, it can be determined that the relative positions of the transmitting coil and the receiving coil have shifted. At this time, the control device can further determine the shift direction of the transmitting coil and the receiving coil based on the real-time relative position and the preset relative position. Based on the determined shift direction, the control device can calculate the direction of the magnetic field lines that the transmitting coil should pass through in the first magnetic field line through-hole S1 to the fourth magnetic field line through-hole S4 when transmitting electrical energy to the shifted receiving coil. Based on the direction of the magnetic field lines that should pass through in the first magnetic field line through-hole S1 to the fourth magnetic field line through-hole S4, the control device can determine the direction of the current that should flow in the first transmitting winding L1 and the second transmitting winding L2, respectively. The control device can also adjust the phase of the PWM signal output to at least one of the first inverter circuit 20 and the second inverter circuit 30 according to the determined current direction that should flow through the first transmitting winding L1 and the second transmitting winding L2. This allows the inverter circuit receiving the adjusted PWM signal to correspondingly change the phase of the output AC current, thereby ensuring that the current direction flowing through the first transmitting winding L1 and the second transmitting winding L2 is consistent with the determined current direction. This allows the transmitting coil to still efficiently transmit electrical energy to the deviated receiving coil. In this way, the anti-deviation characteristics of the transformer in the wireless power transmission system can be enhanced.

[0079] This embodiment discloses two specific methods for adjusting the phase of the alternating current. In this embodiment, the first magnetic field line through-hole S1 and the fourth magnetic field line through-hole S4 can be located at the upper left and lower right respectively in a grid arrangement, and the second magnetic field line through-hole S2 and the third magnetic field line through-hole S3 can be located at the upper right and lower left respectively in a grid arrangement. Here, the direction from the third magnetic field line through-hole S3 to the fourth magnetic field line through-hole S4 in the transmitting coil is defined as the X direction, and the direction from the third magnetic field line through-hole S3 to the first magnetic field line through-hole S1 in the transmitting coil is defined as the Y direction, and the X direction can be perpendicular to the Y direction.

[0080] When the relative positions of the transmitting coil and the receiving coil shift in the X direction, the transformer control method of the present invention can control the phase difference between the first inverter circuit 20 and the second inverter circuit 30 to ensure that the magnetic field directions of the first magnetic field through-hole S1 and the second magnetic field through-hole S2 are the same at every moment, thereby enabling the transformer to resist the influence of the shift in the X direction on power transmission. See details for further information. Figure 3 , Figure 3 This diagram illustrates the direction of the magnetic field lines traversed by the transmitting coil at a given moment, assuming a shift in the relative positions of the transmitting and receiving coils in the X direction and the transformer is controlled using the transformer control method described in this application. Figure 3 In the illustrated embodiment, the magnetic field lines passing through the first magnetic field line through-hole S1 and the second magnetic field line through-hole S2 are both directed outwards from the plane containing the transmitting coil, while the magnetic field lines passing through the third magnetic field line through-hole S3 and the fourth magnetic field line through-hole S4 are directed inwards from the plane containing the transmitting coil. In other words, the current direction in the rectangular annular coil containing the first magnetic field line through-hole S1 and the second magnetic field line through-hole S2 is counterclockwise, and the current direction in the rectangular annular coil containing the third magnetic field line through-hole S3 and the fourth magnetic field line through-hole S4 is clockwise.

[0081] When the relative positions of the transmitting coil and the receiving coil shift in the Y direction, the transformer control method of the present invention can control the phase difference between the first inverter circuit 20 and the second inverter circuit 30 so that the magnetic field directions of the first magnetic field line through-hole S1 and the second magnetic field line through-hole S2 are opposite at every moment, thereby enabling the transformer to resist the influence of the shift in the Y direction on power transmission. See details for further information. Figure 4 , Figure 4 This diagram illustrates the direction of the magnetic field lines traversed by the transmitting coil at a given moment, assuming a shift in the relative positions of the transmitting and receiving coils in the Y direction and the transformer is controlled using the transformer control method described in this application. Figure 4 In the illustrated embodiment, the magnetic field lines passing through the first magnetic field line through-hole S1 and the third magnetic field line through-hole S3 are directed outwards from the plane containing the transmitting coil, while the magnetic field lines passing through the second magnetic field line through-hole S2 and the fourth magnetic field line through-hole S4 are directed inwards from the plane containing the transmitting coil. In other words, the current direction in the rectangular annular coil containing the first magnetic field line through-hole S1 and the third magnetic field line through-hole S3 is counterclockwise, and the current direction in the rectangular annular coil containing the second magnetic field line through-hole S2 and the fourth magnetic field line through-hole S4 is clockwise.

[0082] Optionally, the high-offset-resistance loosely coupled transformer control method further includes:

[0083] Before controlling the high-offset-resistance loosely coupled transformer to transmit electrical energy, the phase of the first inverter circuit is controlled to be a first preset phase, and the phase of the second inverter circuit is controlled to be a second preset phase, wherein the difference between the second preset phase and the first preset phase is not less than 0° and not greater than 180°.

[0084] The difference between the first preset phase and the second preset phase is not less than 0° and not greater than 180°.

[0085] In this embodiment, the control device can control one of the first preset phase and the second preset phase to 0°, and control the other to be within a range of not less than 0° and not greater than 180°. This allows the difference between the first preset phase and the second preset phase to be within a range of not less than 0° and not greater than 180° by adjusting the phase of the second preset phase, which also helps reduce the complexity of program design. Of course, in other optional embodiments, the first preset phase and the second preset phase, which are controlled to be 0° in the above embodiment, can also be controlled to be an angle greater than 0°, which will not be elaborated here. In another optional embodiment, when the first preset phase is 0°, the second preset phase can be 180°. This setting can further reduce the variation of the transformer's coupling coefficient under the condition of the transformer being offset at the same position.

[0086] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A loosely coupled transformer with high anti-offset characteristics, applied in a wireless power transmission system, characterized in that, The wireless power transmission system includes a DC power supply, a first inverter circuit, a second inverter circuit, a first compensation network, a second compensation network, a third compensation network, a fourth compensation network, and a rectifier circuit. The input terminals of the first and second inverter circuits are respectively connected to the DC power supply. The output terminals of the third and fourth compensation networks are respectively connected to the input terminals of the rectifier circuit. The output terminal of the rectifier circuit is connected to the load. The high-offset-resistance loosely coupled transformer includes: The transmitting coil includes a first transmitting winding and a second transmitting winding. The first transmitting winding has a first magnetic field line through-hole and a fourth magnetic field line through-hole, and the second transmitting winding has a second magnetic field line through-hole and a third magnetic field line through-hole. The first, second, third, and fourth magnetic field line through-holes are arranged in a grid pattern. The first transmitting winding is connected to the output terminal of the first inverter circuit via a first compensation network, and the second transmitting winding is connected to the output terminal of the second inverter circuit via a second compensation network. The first transmitting winding forms a first magnetic field line through-hole and a fourth magnetic field line through-hole arranged diagonally; the first transmitting winding is used to control the direction of the magnetic field lines passing through the first magnetic field line through-hole and the fourth magnetic field line through-hole according to the AC current output after compensation by the first compensation network; the second transmitting winding forms a second magnetic field line through-hole and a third magnetic field line through-hole arranged diagonally; the second transmitting winding is used to control the direction of the magnetic field lines passing through the second magnetic field line through-hole and the third magnetic field line through-hole according to the AC current output by the second inverter circuit; The receiving coil includes a first receiving winding and a second receiving winding arranged orthogonally. The first receiving winding is connected to the input terminal of the third compensation network, and the second receiving winding is connected to the input terminal of the fourth compensation network.

2. The high-displacement-resistance loosely coupled transformer as described in claim 1, characterized in that, When the first transmitting winding is connected to the AC current output after compensation by the first compensation network, the magnetic field lines passing through the first magnetic field line through hole and the fourth magnetic field line through hole are in opposite directions.

3. The high-displacement-resistance loosely coupled transformer as described in claim 1, characterized in that, When the second transmitting winding is connected to the AC current output after compensation by the second compensation network, the magnetic field lines passing through the second magnetic field line through-hole and the third magnetic field line through-hole are in opposite directions.

4. The high-displacement-resistance loosely coupled transformer as described in claim 1, characterized in that, The conductive coils on the first and second transmitting windings are wound in a figure-eight pattern.

5. The high-displacement-resistance loosely coupled transformer as described in claim 1, characterized in that, The first receiving winding and the second receiving winding are orthogonally stacked to form a first channel, a second channel, a third channel and a fourth channel that pass through the receiving coil and are arranged in a grid pattern.

6. The high-displacement-resistance loosely coupled transformer as described in claim 5, characterized in that, The first receiving winding includes an interconnected first winding portion and a second winding portion, wherein the first winding portion forms a fifth magnetic field line through-hole, and the second winding portion forms a sixth magnetic field line through-hole. The second receiving winding includes an interconnected third winding portion and a fourth winding portion, wherein the third winding portion forms a seventh magnetic field line through-hole and the fourth winding portion forms an eighth magnetic field line through-hole. A portion of the fifth magnetic field line through-hole and a portion of the seventh magnetic field line through-hole are connected to form the first channel, and another portion of the fifth magnetic field line through-hole and a portion of the eighth magnetic field line through-hole are connected to form the third channel; A portion of the sixth magnetic field line through-hole and another portion of the seventh magnetic field line through-hole are connected to form the second channel, and another portion of the sixth magnetic field line through-hole and another portion of the eighth magnetic field line through-hole are connected to form the fourth channel.

7. A control method for a loosely coupled transformer with high anti-offset characteristics, applied to a wireless power transmission system, characterized in that, The wireless power transmission system includes a DC power supply, a first inverter circuit, a second inverter circuit, a first compensation network, a second compensation network, a third compensation network, a fourth compensation network, a rectifier circuit, and a high-offset-resistance loosely coupled transformer as described in any one of claims 1-6. The input terminals of the first and second inverter circuits are respectively connected to the DC power supply. The output terminal of the first inverter circuit is connected to the first transmitting winding of the high-offset-resistance loosely coupled transformer via the first compensation network. The output terminal of the second inverter circuit is connected to the second transmitting winding of the high-offset-resistance loosely coupled transformer via the second compensation network. The input terminal of the third compensation network is connected to the first receiving winding of the high-offset-resistance loosely coupled transformer. The input terminal of the fourth compensation network is connected to the second receiving winding of the high-offset-resistance loosely coupled transformer. The output terminals of the third and fourth compensation networks are respectively connected to the input terminal of the rectifier circuit. The output terminal of the rectifier circuit is connected to the load. The high-offset-resistance loosely coupled transformer control method includes: Determine whether the transmitting and receiving coils in a loosely coupled transformer with high offset resistance are offset; When it is determined that the transmitting and receiving coils of a loosely coupled transformer with high anti-offset characteristics are offset, the offset direction of the transmitting and receiving coils is determined. Based on the determined offset direction, the phase difference between the first inverter circuit and the second inverter circuit is controlled.

8. The high-offset-resistance loosely coupled transformer control method as described in claim 7, characterized in that, The high-offset-resistance loosely coupled transformer control method further includes: Before controlling the high offset resistance loosely coupled transformer to transmit electrical energy, the phase of the first inverter circuit is controlled to be a first preset phase, and the phase of the second inverter circuit is controlled to be a second preset phase. The difference between the first preset phase and the second preset phase is not less than 0° and not greater than 180°.

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