A spatial wireless charging system based on a three-phase frustum-shaped transmitting mechanism

Abstract

The present invention provides a space wireless charging system based on a three-phase frustum-shaped transmitting mechanism; the three-phase transmitting coils A, B, and C have the same size, structure, and number of turns of the coil, and form a three-phase frustum-shaped transmitting mechanism; there are gaps in the overlapping parts of the three-phase transmitting coils A, B, and C pairwise; by changing the current phase, the three-phase frustum-shaped transmitting coils A, B, and C are controlled to obtain stable power transmission; the mutual inductance between the transmitting and receiving coils is analyzed, and the input power, output power, and transmission efficiency of the wireless charging system are analyzed to obtain uniform and stable energy transmission; the transmitting mechanism of the present invention adopts a frustum-shaped three-dimensional transmitting coil, which can simultaneously achieve wireless power transmission inside and outside the space; and the coupling mechanism does not need to adopt a magnetic core, and the receiving coil does not need to be three-dimensional, and the weight is relatively light, which is beneficial to the lightweight of the receiving end.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless power transmission, and specifically relates to a spatial wireless charging system based on a three-phase frustum-shaped transmitting mechanism. Background Art

[0002] The background art of the present invention is the spatial multi-degree-of-freedom wireless charging technology of wireless power transmission technology; wireless power transfer (WPT) technology has been widely used in application scenarios such as implantable medical fields, oil drilling, underwater vehicles, and electric vehicles because it can solve the disadvantages of traditional wired power transmission, such as easy generation of electric sparks, potential safety hazards, and poor convenience. However, when planar WPT applied to electronic device fields such as smartphones and laptops performs wireless charging, the receiving coil needs to be completely aligned with the transmitting coil and closely attached to the wireless charger. Planar WPT cannot overcome the problem that when a portable mobile electronic device has a position offset or an angular deflection, the system output power and transmission efficiency will be greatly reduced, and even when the electronic device has a large deflection, the system cannot achieve wireless charging, reducing the convenience of use. Therefore, to overcome the disadvantages of low degree of freedom and poor anti-offset ability of planar wireless power transmission technology, spatial WPT has emerged. Spatial WPT means that within an effective charging area, the relative position change between the load and the wireless charger has little effect on the energy received by the load, and the load can perform wireless charging at any position in space. Spatial WPT has attracted the attention of domestic and foreign research scholars due to its advantages such as good position robustness, strong safety and reliability, and good environmental affinity.

[0003] The existing technologies have the following problems:

[0004] First, the novel transmitting coil structures such as the bowl-shaped, spherical, and three-dimensional structures wound by a single wire proposed currently can only achieve wireless power transmission inside or outside the space, and cannot achieve wireless power transmission both inside and outside the space at the same time;

[0005] Second, the three-dimensional structure of the receiving coil proposed currently results in a large volume of the receiving end, which is not conducive to the lightweight of the receiving end;

[0006] Third, the wireless power transmission system that uses a cross-shaped magnetic core to achieve multi-degree-of-freedom reception proposed currently has an increased weight of the entire system due to the addition of the magnetic core. Summary of the Invention

[0007] To solve the above problems, the present invention proposes a spatial wireless charging system based on a three-phase frustum-shaped transmitting mechanism.

[0008] The present invention is realized through the following technical solutions:

[0009] A three-phase frustum-shaped transmitting mechanism:

[0010] The three-phase transmitting coils A, B, and C form a three-phase frustum-shaped transmitting mechanism;

[0011] The three-phase transmitting coils A, B, and C have exactly the same size, structure, and number of turns;

[0012] There are gaps in the overlapping parts of the three-phase transmitting coils A, B, and C;

[0013] The intersections formed by the pairwise overlaps of the three-phase transmitting coils A, B, and C are A 1 A 2 X 1 X 2 , B 1 B 2 Y 1 Y 2 and C 1 C 2 Z 1 Z 2 ;

[0014] The A-phase transmitting coil includes the intersection point A 1 A 2 X 1 X 2 ;

[0015] The B-phase transmitting coil includes the intersection point B 1 B 2 Y 1 Y 2 ;

[0016] The C-phase transmitting coil includes the intersection point C 1 C 2 Z 1 Z 2 ;

[0017] The distance between the upper and lower semi-circular transmitting coils of the three-phase frustum-shaped transmitting mechanism is D = 200 mm, and the size relationship between the upper and lower semi-circular transmitting coils is: R 2 = 2R 1 = 200 mm.

[0018] A space wireless charging system for a three-phase frustum-shaped transmitting mechanism:

[0019] The wireless charging system includes a transmitting end and a receiving end;

[0020] The transmitting end includes a DC power supply U in , a three-phase full-bridge inverter circuit, a primary resonant compensation circuit, and the three-phase transmitting coils A, B, and C of the magnetic coupling mechanism;

[0021] The receiving end includes a receiving coil, a secondary resonant compensation circuit, a full-bridge rectifier circuit, a filtering circuit, and a load;

[0022] The DC power supply, the three-phase full-bridge inverter circuit, and the primary resonant compensation circuit are connected in sequence, and the secondary resonant compensation circuit, the rectifying and filtering circuit, and the load are connected in sequence.

[0023] Furthermore,

[0024] The three-phase full-bridge inverter circuit includes three single-phase inverter circuits A, B, and C;

[0025] The phase-A inverter circuit includes four switching tubes V 1 , V 2 , V 3 , V 4 ;

[0026] The phase-B inverter circuit includes four switching tubes V 5 , V 6 , V 7 , V 8 ;

[0027] The phase-C inverter circuit includes four switching tubes V 9 , V 10 , V 11 , V 12 ;

[0028] The primary resonant compensation circuit includes compensation capacitors C A , C B , and C C ;

[0029] The secondary resonant compensation circuit includes a compensation capacitor C S ;

[0030] The full-bridge rectifier circuit includes diodes D 1 , D 2 , D 3 , and D 4 ;

[0031] The filtering circuit includes a filtering capacitor C.

[0032] Furthermore,

[0033] The positive pole of the DC power supply U in is respectively connected to one ends of the switching tubes V 1 , V 3 , V 5 , V 7 , V 9 , and V 11 ;

[0034] The DC power supply Uin The negative electrodes of 2 are respectively connected to the switching transistors V 4 、V 6 、V 8 、V 10 and V 12 at one ends;

[0035] The other ends of the switching transistors V 1 and V 2 are connected to one end of the compensation capacitor C A of the transmitting coil A. The other end of the compensation capacitor C A and the other ends of the switching transistors V 3 and V 4 are connected to the transmitting coil A;

[0036] The other ends of the switching transistors V 5 and V 6 are connected to one end of the compensation capacitor C B of the transmitting coil B. The other end of the compensation capacitor C B and the other ends of the switching transistors V 7 and V 8 are connected to the transmitting coil B;

[0037] The other ends of the switching transistors V 9 and V 10 are connected to one end of the compensation capacitor C C of the transmitting coil C. The other end of the compensation capacitor C C and the other ends of the switching transistors V 11 and V 12 are connected to the transmitting coil C.

[0038] Furthermore,

[0039] One end of the receiving coil is connected to one end of the compensation capacitor C S . The other end of the compensation capacitor C S is respectively connected to one ends of the diodes D 1 、D 2 . The receiving coil is also connected to one ends of the diodes D 3 、D 4 ;

[0040] One end of the load R is respectively connected to one end of the filter capacitor C and one ends of the diodes D 1 、D 3 at the other ends;

[0041] The other end of the load R is respectively connected to the other end of the filter capacitor C and one ends of the diodes D 2 、D 4 at the other ends.

[0042] Control method for a spatial wireless charging system based on a three-phase frustum-shaped transmitting mechanism:

[0043] Step 1: Control the three-phase transmitting coils A, B, and C by changing the current phase to obtain stable power transmission;

[0044] Step 2: Analyze the input power, output power, and transmission efficiency of the wireless charging system by analyzing the mutual inductance between the transmitting and receiving coils.

[0045] Further, in Step 1,

[0046] Control the transmitting mechanism by controlling the current phases of the three-phase transmitting coils A, B, and C;

[0047]

[0048] where i A is the current passing through transmitting coil A, i B is the current passing through transmitting coil B, i C is the current passing through transmitting coil C, I m is the current amplitude, ω is the operating angular frequency, t is the time, ψ A is the initial phase of the current in transmitting coil A, ψ B is the initial phase of the current in transmitting coil B, ψ C is the initial phase of the current in transmitting coil C;

[0049] The control method specifically includes:

[0050] Zero-sequence control: ψ A = ψ B = ψ C = 0°;

[0051] That is, the excitations of the three-phase transmitting coils A, B, and C are equal and 0;

[0052] Positive-sequence control: ψ A = 0°, ψ B = -120°, ψ C = 120°;

[0053] That is, the excitation phases of the three-phase transmitting coils A, B, and C differ from each other by 120° in sequence.

[0054] Further, in Step 2,

[0055] Adopt the fundamental wave analysis method to equivalent the DC power supply U in at the transmitting end and the three-phase full-bridge inverter circuit to a three-phase AC input voltage source; equivalent the full-bridge rectifier circuit, filter circuit, and load at the receiving end to a resistor,

[0056] Then, according to Kirchhoff's voltage law, the KVL equation is written for the equivalent circuit model as follows:

[0057]

[0058] Where the phasors represent the fundamental output voltages of the three-phase inverter respectively, represent the fundamental currents of the transmitting coil respectively, represents the fundamental current of the receiving coil; R A 、R B 、R C represent the internal resistances of the receiving coil respectively; Z S represents the equivalent impedance at the receiving end;

[0059] Then the input power P in 、output power P out and transmission efficiency η of the system are respectively:

[0060]

[0061] According to Neumann's formula, the mutual inductance expression is:

[0062]

[0063] Where: N 1 、N 2 represent the number of turns of two coils in space respectively; μ 0 is the magnetic permeability of vacuum, and its value is 4π×10 -7 H / m; R represents the distance between any two points located in the two coils;

[0064] When the receiving coil rotates at a position 50 mm away from the z-axis axially inside the transmitting mechanism, taking the A-phase transmitting coil as an example, a model is established for the receiving coil and the transmitting coil;

[0065] At this time, the upper and lower semicircles of the receiving coil and the transmitting coil are orthogonal to each other. Analyze the mutual inductance between the long straight wire l 1 A 2 in the A 1 direction and the receiving coil, and the long straight wire l 1 X 2 in the X 2 direction;

[0066] For the long straight wire l 1 A 2 in the A 1 direction, the long straight wire l 1 X 2 in the X 2 direction and the receiving coil, mathematical models are established respectively;

[0067]

[0068]

[0069]

[0070] R 1 is the upper radius of the transmitting coil, R 2 is the lower radius of the transmitting coil, D is the height of the transmitting coil, r is the radius of the receiving coil, H is the distance between the receiving coil and the transmitting coil, β is the rotation angle of the receiving coil, R S is the receiving coil;

[0071] According to Neumann's formula, for a long straight wire l 1 、l 2 the mutual inductances with the receiving coil are respectively:

[0072]

[0073]

[0074] When the receiving coil rotates inside the transmitting mechanism, the mutual inductance between the receiving coil and the A-phase transmitting coil is:

[0075]

[0076] Similarly, the calculation formulas for the mutual inductances between the receiving coil and the B-phase and C-phase transmitting coils can be obtained.

[0077] An electronic device includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of the method described in any one of the above are implemented.

[0078] A computer-readable storage medium is used to store computer instructions. When the computer instructions are executed by a processor, the steps of the method described in any one of the above are implemented.

[0079] Advantages of the present invention

[0080] The transmitting mechanism of the present invention adopts a frustum-shaped three-dimensional transmitting coil, which can simultaneously achieve wireless power transmission both inside and outside the space;

[0081] The coupling mechanism of the present invention does not need to use a magnetic core, and the receiving coil does not need to be three-dimensional, so the weight of the entire coupling mechanism is relatively light, which is beneficial to the lightweight of the receiving end. Description of the drawings

[0082] Figure 1 is a schematic three-dimensional structure diagram of the three-phase cylindrical transmitting coil of the present invention;

[0083] Figure 2 is a structural block diagram of the space wireless charging system of the present invention;

[0084] Figure 3 is the frustum-shaped launching mechanism simulation model of the present invention;

[0085] Figure 4 is the magnetic field simulation comparison diagram under zero-sequence control of the present invention, where (a) is the top view, (b) is the front view, and (c) is the side view;

[0086] Figure 5 is the magnetic field simulation comparison diagram under positive-sequence control of the present invention, where (a) is the top view, (b) is the front view, and (c) is the side view;

[0087] Figure 6 is the main circuit model of the spatial WPT system based on the three-phase frustum-shaped launching mechanism of the present invention;

[0088] Figure 7 is the equivalent circuit model of the spatial WPT system based on the three-phase frustum-shaped launching mechanism of the present invention;

[0089] Figure 8 is the mutual inductance model when the receiving coil of the present invention rotates inside the launching mechanism;

[0090] Figure 9 is the mutual inductance curve between the transmitting and receiving coils when the receiving coil of the present invention rotates inside and outside the launching mechanism, where (a) is the curve of the deflection angle inside the launching mechanism and the mutual inductance, and (b) is the curve of the deflection angle outside the launching mechanism and the mutual inductance;

[0091] Figure 10 is the output voltage change curve when the receiving coil of the present invention rotates inside and outside the launching mechanism. Specific embodiments

[0092] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0093] In conjunction with Figures 1 to 10 .

[0094] A three-phase frustum-shaped launching mechanism, characterized in that:

[0095] The three-phase transmitting coils A, B, and C form a three-phase frustum-shaped launching mechanism; the three-phase transmitting coils A, B, and C are successively 120° apart;

[0096] The three-phase transmitting coils A, B, and C have the same size, structure, and number of turns of the coil;

[0097] There are gaps in the overlapping parts of the three-phase transmitting coils A, B, and C.

[0098] The intersections formed by the pairwise overlaps of the three-phase transmitting coils A, B, and C are A 1 A 2 X 1 X 2 , B 1 B 2 Y 1 Y 2 and C 1 C 2 Z 1 Z 2 ;

[0099] The phase-A transmitting coil includes the intersection point A 1 A 2 X 1 X 2 ; The phase-B transmitting coil includes the intersection point B 1 B 2 Y 1 Y 2 ; The phase-C transmitting coil includes the intersection point C 1 C 2 Z 1 Z 2 ;

[0100] The distance between the upper and lower semi-circular transmitting coils of the three-phase frustum-shaped transmitting mechanism is D = 200 mm, and the size relationship between the upper and lower semi-circular transmitting coils is: R 2 = 2R 1 = 200 mm. The direction indicated by the arrow in the figure is the direction of the current excitation applied to the coil.

[0101] A space wireless charging system based on a three-phase frustum-shaped transmitting mechanism:

[0102] As Figure 2 shown, the wireless charging system includes a transmitting end and a receiving end;

[0103] The transmitting end includes a DC power supply U in , a three-phase full-bridge inverter circuit, a primary resonant compensation circuit, and the three-phase frustum-shaped transmitting coils A, B, and C of the magnetic coupling mechanism;

[0104] The receiving end includes a receiving coil, a secondary resonant compensation circuit, a full-bridge rectifier circuit, a filtering circuit, and a load;

[0105] The DC power supply, the three-phase full-bridge inverter circuit, and the primary resonant compensation circuit are connected in sequence, and the secondary resonant compensation circuit, the rectifier filtering circuit, and the load are connected in sequence.

[0106] When the receiving coil is located at different positions in space, the three-phase transmitting coil is excited with currents of the same amplitude but different phases, resulting in different spatial magnetic fields generated by the three-phase transmitting coil accordingly. Therefore, by controlling the angle of the current phase, a three-phase frustum-shaped transmitting mechanism can generate an omnidirectional spatially uniform rotating magnetic field, enabling the receiving coil to receive energy at any position in space.

[0107] The three-phase full-bridge inverter circuit includes three single-phase inverter circuits A, B, and C;

[0108] The A-phase inverter circuit includes four switching tubes V 1 , V 2 , V 3 , V 4 ;

[0109] The B-phase inverter circuit includes four switching tubes V 5 , V 6 , V 7 , V 8 ;

[0110] The C-phase inverter circuit includes four switching tubes V 9 , V 10 , V 11 , V 12 ;

[0111] The primary resonant compensation circuit includes compensation capacitors C A , C B , and C C ;

[0112] The secondary resonant compensation circuit includes compensation capacitor C S ;

[0113] The full-bridge rectifier circuit includes diodes D 1 , D 2 , D 3 , and D 4 ;

[0114] The filter circuit includes filter capacitor C.

[0115] The positive pole of the DC power supply U in is respectively connected to one ends of switching tubes V 1 , V 3 , V 5 , V 7 , V 9 , and V 11 ;

[0116] The negative pole of the DC power supply U in is respectively connected to switching tubes V 2 , V 4, V 6 , V 8 , V 10 and V 12 are connected to one end;

[0117] The other ends of the switching tubes V 1 and V 2 are connected to one end of the compensation capacitor C of the transmitting coil A, and the other end of the compensation capacitor C A and the other ends of the switching tubes V A and V 3 and V 4 are connected to the transmitting coil A;

[0118] The other ends of the switching tubes V 5 and V 6 are connected to one end of the compensation capacitor C of the transmitting coil B, and the other end of the compensation capacitor C B and the other ends of the switching tubes V B and V 7 and V 8 are connected to the transmitting coil B;

[0119] The other ends of the switching tubes V 9 and V 10 are connected to one end of the compensation capacitor C of the transmitting coil C, and the other end of the compensation capacitor C C and the other ends of the switching tubes V C and V 11 and V 12 are connected to the transmitting coil C.

[0120] The receiving coil is connected to one end of the compensation capacitor C S , and the other end of the compensation capacitor C S is respectively connected to one end of the diodes D 1 , D 2 ; the receiving coil is also connected to the diodes D 3 , D 4 ;

[0121] One end of the load R is respectively connected to one end of the filter capacitor C and the other ends of the diodes D 1 , D 3 ;

[0122] The other end of the load R is respectively connected to the other end of the filter capacitor C and the other ends of the diodes D 2 , D 4 ;

[0123] A control method for a space wireless charging system based on a three-phase frustum-shaped transmitting mechanism, characterized in that:

[0124] Step 1: Control the three-phase frustum-shaped transmitting coils A, B, and C by changing the current phase to obtain stable power transmission.

[0125] Step 2: Analyze the input power, output power, and transmission efficiency of the wireless charging system by analyzing the mutual inductance between the transmitting and receiving coils.

[0126] During the simulation process, there should be no contact between the three-phase transmitting coils. Therefore, to ensure the normal operation of the simulation, the radii of the transmitting coils should be slightly different. At the same time, when an alternating current excitation is applied to the three-phase transmitting coils, a rotating magnetic field can be generated in space. However, for different amplitudes and phase angles of the three-phase alternating current, the magnetic field distribution and magnitude generated are also different.

[0127] To simplify the analysis, the present invention controls the transmitting mechanism by controlling the current phases of the three-phase frustum-shaped transmitting coils A, B, and C;

[0128]

[0129] where i A is the current passing through the transmitting coil A, i B is the current passing through the transmitting coil B, i C is the current passing through the transmitting coil C, I m is the current amplitude, ω is the working angular frequency, t is the time, ψ A is the initial phase of the current of the transmitting coil A, ψ B is the initial phase of the current of the transmitting coil B, ψ C is the initial phase of the current of the transmitting coil C;

[0130] Due to the symmetry of the transmitting mechanism, the control method specifically includes:

[0131] Zero-sequence control: ψ A = ψ B = ψ C = 0°;

[0132] That is, the excitations of the three-phase frustum-shaped transmitting coils A, B, and C are equal and 0; the three-view drawings of the rotating magnetic field generated by the frustum-shaped transmitting mechanism in the initial state are as Figure 4 shown.

[0133] Positive-sequence control: ψ A = 0°, ψ B = -120°, ψ C = 120°;

[0134] That is, the excitation phases of the three-phase frustum-shaped transmitting coils A, B, and C differ by 120° in sequence; the three-view drawings of the rotating magnetic field generated by the two transmitting mechanisms in the initial state are as Figure 5 shown.

[0135] When positive-sequence control is adopted, from Figure 5 (b), it can be seen that the magnetic induction intensity generated by the frustum-shaped transmitting coil shows a gradually increasing trend from bottom to top. When the receiving coil is located at the top, the magnetic induction intensity generated by the frustum-shaped transmitting coil here slightly decreases. The reason for this phenomenon may be that the magnetic leakage of the system is relatively large at the top of the transmitting coil, resulting in a relatively small magnetic induction intensity generated by it.

[0136] Comparing Figure 4 and Figure 5 with the magnetic field simulation diagrams of the transmitting mechanism, it can be known that although the maximum value of the magnetic induction intensity under positive-sequence control is not as strong as that under zero-sequence control, its magnetic field distribution is more uniform, which is more suitable for spatial wireless power transmission, and there is no dead zone phenomenon, which can ensure the stability of the system transmission.

[0137] In summary, the present invention controls the transmitting coil by adopting a current positive-sequence control method with phase angles differing by 120° each, and the receiving coil obtains relatively stable energy accordingly.

[0138] The main circuit model is analyzed as follows by using the fundamental wave analysis method. The DC power supply U in at the transmitting end and the three-phase full-bridge inverter circuit are equivalent to a three-phase AC input voltage source; the full-bridge rectifier circuit, filter circuit, and load at the receiving end are equivalent to a resistor, and the equivalent simplified circuit of the spatial WPT system is as shown in Figure 7 .

[0139] L A , L B , L C respectively represent the self-inductances of the three transmitting coils, L S is the self-inductance of the receiving coil,

[0140] R A , R B , R C and R S respectively represent the internal resistances of the three-phase transmitting coils and the receiving coil, and R eq is the equivalent load resistance at the receiving end;

[0141] Then, according to Kirchhoff's voltage law, the KVL equation is written for the equivalent circuit model shown in Figure 7 as follows:

[0142]

[0143] where the phasors respectively represent the fundamental wave output voltages of the three-phase inverter, respectively represent the fundamental wave currents of the transmitting coils, represents the fundamental wave current of the receiving coil; R A , RB , R C Respectively represent the internal resistance of the receiving coil; Z S Represents the equivalent impedance of the receiving end;

[0144] Then the input power of the system is P in , output power P out And the transmission efficiency η are:

[0145]

[0146] In summary, the factors that affect the output power change mainly include: load resistance, mutual inductance between the transmitting coil and the receiving coil, and three-phase input current.

[0147] When the load resistance is determined, the mutual inductance between the receiving and transmitting coils changes as the position of the receiving coil changes, thereby causing the system output power to change; different output powers can be obtained by controlling the output of the three-phase inverter at the transmitting end of the system.

[0148] Therefore, it is necessary to analyze the mutual inductance between the transmitting and receiving coils.

[0149] According to Nie Yiman's formula, the mutual inductance expression is:

[0150]

[0151] Where: N 1 、N 2 Respectively represent the number of turns of the two coils in space; μ 0 is the vacuum permeability, which is 4π×10 -7 H / m; R represents the distance between any two points in the two coils;

[0152] When the receiving coil rotates at a distance of 50 mm from the z-axis inside the transmitting mechanism, taking the A-phase transmitting coil as an example, Figure 8 As shown, the receiving coil and the transmitting coil are modeled.

[0153] Since the upper and lower semicircles of the receiving coil and the transmitting coil are orthogonal to each other, there is no need to analyze the mutual inductance between the two. It is only necessary to analyze the two long straight wires l 1 , l 2 The mutual inductance between the receiving coil and the receiving coil can be used to mathematically model these three parts.

[0154] A 1 A 2 Direction long straight wire 1 , X 1 X 2 Direction long straight wire 2 The receiving coil and the receiving coil are mathematically modeled separately;

[0155]

[0156]

[0157]

[0158] R 1 is the upper radius of the transmitting coil, R 2 is the lower radius of the transmitting coil, D is the height of the transmitting coil, r is the radius of the receiving coil, H is the distance between the receiving coil and the transmitting coil, β is the rotation angle of the receiving coil, R S is the receiving coil

[0159] According to Neumann's formula, for a long straight wire l 1 、l 2 the mutual inductances with the receiving coil are respectively:

[0160]

[0161]

[0162] When the receiving coil rotates inside the transmitting mechanism, the mutual inductance between the receiving coil and the A-phase transmitting coil is obtained as:

[0163]

[0164] Similarly, the calculation formulas for the mutual inductances between the receiving coil and the B- and C-phase transmitting coils can be obtained.

[0165] Due to the positional relationship of the transmitting mechanism, the mutual inductances between the receiving coil and the A-, B-, and C-phase transmitting coils show a 120° symmetric relationship. Taking r = 83 mm, N 1 = 9, N 2 = 20, β ∈ (0, 2π), the receiving coil rotates 10° each time, and substituting the data into formula (10), the mutual inductance curves between the receiving coil and the frustum-shaped transmitting coil in two cases where H = 50 mm inside the transmitting mechanism and H' = 250 mm outside can be obtained as Figure 9 shown.

[0166] From Figure 9 it can be seen that the mutual inductance between the three-phase frustum-shaped transmitting coil and the receiving coil can always be maintained at a relatively high inductance value, and the mutual inductance distribution is also very uniform. Therefore, when the receiving coil deflects in space, the energy received by the receiving coil is relatively uniform.

[0167] Build the circuit model as Figure 6 shown in the simulation software, and the stability of the power obtained by the simulation load when the receiving coil rotates at different positions in space.

[0168] The circuit simulation parameters are shown in the following table.

[0169]

[0170] Table 1 System simulation parameters

[0171] Substituting the analyzed mutual inductance change situation into the main circuit model, the output voltage change curve of the system can be obtained. Since the change of the system output power is positively correlated with the change of the output voltage, the output voltage change curve of the system can represent the stability of the energy received by the receiving coil, as Figure 10 shown.

[0172] As Figure 10 can be seen, when the receiving coil rotates inside the transmitting mechanism, the output voltage of the system fluctuates around 8.63V, and the maximum fluctuation does not exceed 2%; when the receiving coil rotates outside the transmitting mechanism, the output voltage of the system fluctuates around 3.55V, and the maximum fluctuation does not exceed 7%. In summary, when the receiving coil rotates inside and outside the transmitting mechanism, the output voltage of the system fluctuates less, so the energy received by the load fluctuates less, and the output power fluctuation of the three-phase frustum-shaped wireless charging system is also relatively small.

[0173] An electronic device includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of the method described in any one of the above are implemented.

[0174] A computer-readable storage medium is used to store computer instructions, and when the computer instructions are executed by a processor, the steps of the method described in any one of the above are implemented.

[0175] The above has introduced in detail a space wireless charging system based on a three-phase frustum-shaped transmitting mechanism of the present invention, and has elaborated on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A control method for a spatial wireless charging system based on a three-phase frustum-shaped transmitting mechanism, characterized in that: Three-phase transmitting coils A, B, and C form a three-phase frustum-shaped transmitting mechanism; The three-phase transmitting coils A, B, and C have the same size, structure, and number of turns; There are gaps in the overlapping parts of the three-phase transmitting coils A, B, and C pairwise; The intersection points formed by the pairwise overlaps of the three-phase transmitting coils A, B, and C are A 1 A 2 X 1 X 2 , B 1 B 2 Y 1 Y 2 and C 1 C 2 Z 1 Z 2 ; The phase-A transmitting coil includes intersection point A 1 A 2 X 1 X 2 ; The B-phase emission coil includes the intersection point B 1 B 2 Y 1 Y 2 ; The C-phase transmitting coil includes the intersection point C 1 C 2 Z 1 Z 2 ; The distance between the upper and lower semi-circular transmitting coils of the three-phase frustum-shaped transmitting mechanism is D = 200 mm, and the upper radius R of the transmitting coil 1 and the lower radius R of the transmitting coil 2 have the following dimensional relationship: R 2 = 2R 1 = 200 mm; The method specifically includes the following steps: Step 1: Control the three-phase transmitting coils A, B, and C by changing the current phase to obtain stable power transmission; Step 2: Analyze the input power, output power, and transmission efficiency of the wireless charging system by analyzing the mutual inductance between the transmitting and receiving coils; The fundamental wave analysis method is used to equivalent the DC power supply U at the transmitting end in and the three-phase full-bridge inverter circuit to a three-phase AC input voltage source; the full-bridge rectifier circuit, filter circuit and load at the receiving end are equivalent to a resistor Then, write the KVL equation for the equivalent circuit model according to Kirchhoff's voltage law as: wherein the phasors respectively represent the fundamental output voltages of the three-phase inverter, respectively represent the fundamental wave current of the transmitting coil, represent the fundamental wave current of the receiving coil; R A 、R B 、R C 、respectively represent the internal resistance of the receiving coil; Z S represents the equivalent impedance at the receiving end; Then the input power P of the system in , the output power P out and the transmission efficiency η are respectively as follows: According to Neumann's formula, the mutual inductance expression is: Where: N 1 and N 2 respectively represent the number of turns of two coils in space; μ 0 is the permeability of vacuum, and its value is 4π×10 -7 H / m; R represents the distance between any two points located in the two coils; When the receiving coil rotates at a position 50 mm away from the z-axis axially inside the transmitting mechanism, taking the A-phase transmitting coil as an example, model the receiving coil and the transmitting coil; At this time, the upper and lower semicircles of the receiving coil and the transmitting coil are orthogonal to each other. Analyze A 1 A 2 A long straight wire l in the 1 and X 1 X 2 A long straight wire l in the 2 mutual inductance between the receiving coil; For A 1 A 2 Directional long straight wire l 1 , X 1 X 2 Directional long straight wire l 2 and the receiving coil are respectively subjected to mathematical modeling; R 1 is the upper radius of the transmitting coil, R 2 is the lower radius of the transmitting coil, D is the height of the transmitting coil, r is the radius of the receiving coil, H is the distance between the receiving coil and the transmitting coil, β is the rotation angle of the receiving coil, R S is the receiving coil; According to Neumann's formula, for a long straight wire l 1 and l 2 the mutual inductances with the receiving coil are respectively: It is obtained that when the receiving coil rotates inside the transmitting mechanism, the mutual inductance between the receiving coil and the A-phase transmitting coil is: Similarly, the calculation formulas for the mutual inductance between the receiving coil and the B- and C-phase transmitting coils can be obtained.

2. A control method for a wireless charging system as described in claim 1, characterized in that: The wireless charging system includes a transmitting end and a receiving end; The transmitting end includes a DC power supply U in , a three-phase full-bridge inverter circuit, a primary resonant compensation circuit, and three-phase transmitting coils A, B, and C of a magnetic coupling mechanism; The receiving end includes a receiving coil, a secondary resonant compensation circuit, a full-bridge rectifier circuit, a filtering circuit, and a load; The DC power supply, the three-phase full-bridge inverter circuit, and the primary resonant compensation circuit are connected in sequence, and the secondary resonant compensation circuit, the rectifier filtering circuit, and the load are connected in sequence.

3. According to the control method for a wireless charging system described in claim 2, characterized in that: The three-phase full-bridge inverter circuit includes three single-phase inverter circuits, namely the A-phase inverter circuit, the B-phase inverter circuit, and the C-phase inverter circuit; The phase-A inverter circuit includes four switching transistors V 1 , V 2 , V 3 , V 4 ; The B-phase inverter circuit includes four switching tubes V 5 , V 6 , V 7 , V 8 ; The C-phase inverter circuit includes four switching transistors V 9 , V 10 , V 11 , V 12 ; The primary side resonance compensation circuit includes compensation capacitors C A , C B and C C ; The secondary-side resonant compensation circuit includes a compensation capacitor C S ; The full-bridge rectifier circuit includes diodes D 1 , D 2 , D 3 and D 4 ; The filtering circuit includes a filtering capacitor C.

4. According to the control method for a wireless charging system described in claim 3, characterized in that: The DC power supply U in has its positive pole connected to one end of switching transistors V 1 , V 3 , V 5 , V 7 , V 9 , and V 11 respectively; The DC power supply U in has its negative electrode connected to one end of switching transistors V 2 , V 4 , V 6 , V 8 , V 10 , and V 12 respectively; The switching transistors V 1 and V 2 The other ends of and the compensation capacitor C of the transmitting coil A A One end is connected, and the other end of the compensation capacitor C A The other ends of and the switching transistors V 3 and V 4 The other ends of are connected to the transmitting coil A; The switching transistors V 5 and V 6 The other ends of B and the compensation capacitor C of the transmitting coil B B are connected to one end, and the other end of the compensation capacitor C 7 and the switching transistors V 8 and the other ends of V are connected to the transmitting coil B; The switching transistors V 9 and V 10 The other ends of and the compensation capacitor C of the transmitting coil C C One end of is connected, and the compensation capacitor C C The other end of and the switching transistor V 11 and V 12 The other ends of are connected to the transmitting coil C.

5. According to the control method for a wireless charging system described in claim 4, characterized in that: The receiving coil and the compensation capacitor C S are connected at one end, and the other end of the compensation capacitor C S is respectively connected to one end of the diodes D 1 , D 2 ; the receiving coil is also connected to one end of the diodes D 3 , D 4 ; One end of the load R is respectively connected to one end of the filter capacitor C and the other end of the diode D 1 and D 3 at the other end; The other end of the load R is respectively connected to the other end of the filter capacitor C and the other end of the diode D 2 and D 4 at its other end.

6. According to the control method for a wireless charging system described in claim 1, characterized in that: In step 1, Control the transmitting mechanism by controlling the current phases of the three-phase transmitting coils A, B, and C; where i A is the current passing through transmitting coil A, i B is the current passing through transmitting coil B, i C is the current passing through transmitting coil C, I m is the current amplitude, ω is the working angular frequency, t is the time, ψ A is the initial phase of the current of transmitting coil A, ψ B is the initial phase of the current of transmitting coil B, ψ C is the initial phase of the current of transmitting coil C; The control method specifically includes: Zero-sequence control: ψ A = ψ B = ψ C = 0°; That is, the excitations of the three-phase transmitting coils A, B, and C are equal and 0; Positive sequence control: ψ A = 0°, ψ B = -120°, ψ C = 120°; That is, the excitation phases of the three-phase transmitting coils A, B, and C differ by 120° in sequence.

7. An electronic device, including a memory and a processor, the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method described in claim 1 or 6.

8. A computer-readable storage medium for storing computer instructions, characterized in that, When the computer instructions are executed by the processor, they implement the steps of the method described in claim 1 or 6.

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