Composite anti-rotation offset method for underwater vehicle wireless power transfer system

Abstract

This invention discloses a composite anti-rotational offset method for a wireless power transmission system for underwater vehicles, including an anti-rotational offset coupling mechanism and an anti-rotational offset power stabilization control strategy. The anti-rotational offset coupling mechanism includes two transmitting coil groups and one receiving coil group. The receiving coil group has a ring structure, consisting of six segmented coils connected in series, with adjacent coils having opposite winding directions. The first and second transmitting coil groups each consist of two coils connected in series, with the two transmitting coils in the same group having the same winding direction. The anti-rotational offset power stabilization control strategy achieves stable output power control by real-time acquisition of output power, calculation of the output power change rate, and adjustment of the phase angles of the two inverters. The first inverter drives the first transmitting coil group, and the second inverter drives the second transmitting coil group. This invention improves the system's rotational offset tolerance and achieves stable output power transmission under different rotational offset angles.

Description

Technical Field

[0001] This invention belongs to the field of wireless charging technology, specifically relating to a composite anti-rotation offset method for a wireless power transmission system for underwater vehicles. Background Technology

[0002] Underwater vehicles are effective tools for humankind to develop and utilize the ocean, and are a key research focus for countries worldwide. Energy plays a decisive role in the ability of underwater vehicles to operate continuously for extended periods and perform long-range missions. The widespread application of wireless charging technology provides an effective solution to the problem of power replenishment for underwater vehicles. When underwater vehicles replenish wireless power in the ocean, the impact of ocean currents inevitably causes offset, leading to drastic changes in the mutual inductance between the transmitting and receiving coils, thus affecting the stable transmission of electrical energy. Therefore, to improve the offset resistance of the transmitting and receiving ends during wireless charging of underwater vehicles, several methods can be used to enhance the system's offset tolerance. The first method is through magnetic coupling mechanism design, which improves the system's resistance to rotational offset while ensuring the convergence of the system's magnetic field. The second method is through hybrid compensation topology design to improve the system's tolerance to offset under different operating conditions. The third method is through system control methods, adjusting certain key system parameters in real time to reduce output fluctuations and improve the system's error tolerance. However, using a single method to combat offset during wireless power transmission by underwater vehicles has limitations. Summary of the Invention

[0003] The purpose of this invention is to provide a composite anti-rotational offset method for a wireless power transmission system for underwater vehicles. The receiving coil in the system can be easily embedded in the underwater vehicle's hull, saving internal space. This invention improves the system's rotational offset tolerance and achieves stable power transmission under different rotational offset angles.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] A composite anti-rotation offset method for wireless power transmission systems of underwater vehicles, comprising an anti-rotation offset coupling mechanism and an anti-rotation offset power stabilization control strategy for underwater vehicles;

[0006] The anti-rotation offset coupling mechanism includes two transmitting coil groups and one receiving coil group. The receiving coil group is a ring structure, consisting of six segmented coils connected in series, with adjacent coils having opposite winding directions. The first transmitting coil group and the second transmitting coil group each consist of two coils connected in series, with the two transmitting coils in the same group having the same winding direction.

[0007] The anti-rotation offset power stabilization control strategy includes a primary-side circuit, which consists of a DC power supply, a primary-side controller, a first inverter, a second inverter, a first transmitting coil group, a second transmitting coil group, and a compensation network. The secondary-side circuit consists of a secondary-side coil group, a secondary-side controller, a passive full-bridge rectifier, and a load. The first inverter drives the first transmitting coil group, and the second inverter drives the second transmitting coil group. The primary-side controller adjusts the output voltage phase angle of the first inverter and the second inverter to achieve closed-loop control of the secondary-side output power.

[0008] A further improvement of the present invention is that both transmitting coil groups are solenoid coils with added magnetic cores.

[0009] A further improvement of the present invention is that the receiving coil group is a solenoid coil with a magnetic core.

[0010] A further improvement of the present invention is that the six segmented coils in the receiving coil group are of the same size.

[0011] A further improvement of the present invention is that the four coils of the transmitting coil group are of the same size.

[0012] A further improvement of the present invention is that the magnetic fields generated by the two transmitting coil groups are orthogonal to each other and decoupled from each other.

[0013] A further improvement of the present invention is that the mutual inductance of the receiving coil group and the two transmitting coil groups compensates for each other in order to suppress the change in the equivalent total mutual inductance of the coupling mechanism.

[0014] A further improvement of this invention lies in the fact that the closed-loop control of the secondary-side output power is specifically as follows: the primary-side controller sets the initial phase angle to 90°, the secondary-side controller collects the output power in real time and feeds it back to the primary-side controller via the communication module, and the primary-side controller transmits the collected output power value P. o (k) and desired output power P o_ref The difference is used to obtain the rate of change of output power δ(k). If δ(k) is lower than δ... ref Then the process ends if δ(k) is higher than δ. ref Then, the phase angle of the first and second inverters in the next control cycle decreases by Δθ, and the output power P is collected. o (k+1) and calculate the power change rate δ(k+1). If the output power error δ(k+1) of the next control cycle is smaller than the output power error δ(k) of the previous control cycle, then continue to decrease the phase angle until the power change rate is lower than δ. ref If the output power error δ(k+1) of the next control cycle is greater than the output power error δ(k) of the previous control cycle, then the phase angle between the first inverter and the second inverter in the next control cycle is increased by Δθ, and the output power P is collected. o(k+2) and calculate the power change rate δ(k+2). If the output power change rate in the next control cycle is lower than δ... ref Then the process ends if δ(k) is higher than δ. ref Then continue to increase the phase angle until the power change rate is lower than δ. ref .

[0015] The present invention has at least the following beneficial technical effects:

[0016] 1. The wireless power transmission transmitting coil in this invention consists of two sets of two coils connected in series, and the receiving coil adopts a ring structure of six discrete coils, which is convenient to be embedded in the hull of the underwater vehicle, saving internal space of the underwater vehicle while maintaining its hydrodynamic characteristics.

[0017] 2. When there is a rotational offset between the underwater vehicle and the base station, the transmitting coil and receiving coil in this invention can keep the equivalent total mutual inductance stable under different rotation angles, thereby improving the stability of the output power of the wireless power transmission system.

[0018] 3. By controlling the phase angle between the two sets of inverters, the system matches the phase angle in real time for different rotational offset angles when the underwater vehicle enters the base station, further improving the stability of the system's output power. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the wireless power transmission system for underwater vehicles in this invention;

[0020] Figure 2 This is the anti-rotation offset coupling mechanism for underwater vehicles described in this invention;

[0021] Figure 3 This is a diagram of the LCC-S type circuit topology used in this invention;

[0022] Figure 4 This relates the equivalent total mutual inductance of the coupling mechanism to the rotational offset angle in this invention.

[0023] Figure 5 This is the relationship between the system output power and the phase angle θ between the two inverters when the rotation offset angles are 0°, 10°, 15°, 40°, and 45° respectively.

[0024] Figure 6 This is a block diagram of the phase angle control circuit model in this invention;

[0025] Figure 7 This is a flowchart illustrating the phase angle control principle of this invention. Detailed Implementation

[0026] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] Please see Figure 1 As shown, the coupling mechanism described in this invention allows the receiving coil to be easily embedded in the hull of an underwater vehicle without changing its rotational shape, maintaining its hydrodynamic characteristics, and saving internal space. Figure 2 The present invention discloses a coupling mechanism for resisting rotational offset, comprising two transmitting coil groups and one receiving coil group. The receiving coil group is a ring structure composed of six segmented coils connected in series, with adjacent coils wound in opposite directions. The first and second transmitting coil groups each consist of two coils connected in series, with the two transmitting coils in the same group wound in the same direction. All coils are solenoid coils with incorporated magnetic cores. The six segmented coils in the receiving coil group are of identical size, and the four coils in the transmitting coil group are of identical size. The magnetic fields of the two transmitting coil groups are orthogonal and decoupled from each other. The mutual inductance of the receiving coil group and the two transmitting coil groups compensates for each other to suppress changes in the equivalent total mutual inductance of the coupling mechanism. Because the receiving coil group uses six identical segmented coils arranged in a ring in series, and the rotational offset angle has a rotation cycle of 60°, only the operating conditions when the rotational offset angle is between 0° and 60° are described in detail.

[0028] Figure 3 The circuit topology used in this invention employs an LCC-S type compensation network, where L... f1 and L f2 To compensate for the inductance, C f1 and C f2 C1, C2, and C3 are parallel compensation capacitors; L1, L2, and L3 are series compensation capacitors; and U is the coil self-inductance. bus and U bat These are the input and output DC voltages, R. L It is the load resistance. Since the resonant network parameters of the two sets of transmitting coils are exactly the same, therefore L f1 =L f2 =L f L1 = L2, C f1 =C f2 =C f Since C1 = C2, the system output power can be derived from the fundamental frequency equivalent circuit model as follows:

[0029]

[0030] When the input DC voltage, compensation inductor, and load resistance R are... L When kept constant, the output power is only related to the equivalent total mutual inductance M of the transmitting coil group and the receiving coil group. tot Related.

[0031] Figure 4 M is given 12 M 13 M 23 and M tot The relationship between M and the rotation offset angle. 12 It is the mutual inductance between the first and second transmitting coil groups; M 13 It is the mutual inductance between the first transmitting coil group and the receiving coil group; M 23 It is the mutual inductance between the second transmitting coil group and the receiving coil group, M tot This is the equivalent total mutual inductance value of the receiving coil group and the two transmitting coil groups. The equivalent total mutual inductance can remain relatively stable during one rotational offset cycle. The equivalent total mutual inductance M is [value missing] for rotational offsets of 15° and 45°. tot The error rate is the largest, which in turn leads to the largest deviation in output power.

[0032] To ensure stable output power throughout the rotational offset period from 0° to 60°, a power stabilization control strategy is employed. This involves adjusting the phase angle θ of the output voltages of the two inverters to keep the output power change rate δ below a desired threshold. The output power change rate is defined as δ = |P| o -P o_ref | / P o_ref ×100%, δ in this embodiment ref Take 5%.

[0033] Figure 5 The relationship between system output power and θ is presented when the rotational offset angles are 0°, 10°, 15°, 40°, and 45°. Since the total mutual inductance deviation is largest at 15° and 45° within one rotational offset cycle, the inverter phase angle range required for the power stability control strategy is... Figure 5 The shaded area represents the phase angle range of 81° to 99° in this example. For any rotational offset angle within the defined power change rate range, the system can achieve stable output power within this region.

[0034] Figure 6This is a control block diagram of the power stability control strategy described in this invention. The secondary side collects the output voltage and output current in real time to calculate the output power, and feeds this data back to the primary side controller via a wireless communication module. The primary side controller subtracts the collected output power value from the desired output power to obtain the output power change. Based on the output power change, the equivalent total mutual inductance is calculated, and the phase angle of the output voltages of the two inverters is adjusted accordingly.

[0035] Figure 7 A flowchart of the power stability control strategy described in this invention is provided. When the system starts working, the initial value of the inverter phase angle is given as 90°, and the output voltage and output current are collected in real time to calculate the output power P at the current moment. o (k), calculate the power change rate δ(k), and determine whether the current power change rate δ(k) is lower than the preset threshold δ. ref If δ(k) is already lower than δ ref If the current phase angle changes, the process ends. If δ(k) does not meet the requirements, the phase angle is reduced by Δθ, and the output power is collected. The power change rate δ(k+1) is calculated, and the current power change rate δ(k+1) is compared with the power change rate δ(k) at the previous moment. If the current power change rate δ(k+1) is less than the power change rate δ(k) at the previous moment, it proves that the current phase angle change direction is positive, and it is determined whether δ(k+1) is lower than the preset threshold δ. ref If δ(k+1) is already lower than δ ref If the phase angle Δθ is not met, the process ends; if δ(k+1) does not meet the requirements, the phase angle Δθ is reduced until the power change rate meets the requirements.

[0036] If the current power change rate δ(k+1) is greater than the power change rate δ(k) at the previous moment, it proves that the current phase angle change direction is in the opposite direction. Increase the phase angle by Δθ and collect the output power P. o (k+2), calculate the power change rate δ(k+2), and determine whether δ(k+2) is lower than the preset threshold δ. ref If δ(k+2) is already lower than δ ref If the phase angle Δθ is not met, the process ends; if δ(k+2) does not meet the requirements, the phase angle Δθ is increased until the power change rate meets the requirements.

[0037] In summary, the coil structure proposed in this invention can be easily embedded into the hull of an underwater vehicle, saving internal space while maintaining its hydrodynamic characteristics. This proposed free-rotation wireless power transmission system with segmented electromagnetic coils improves the system's resistance to rotational deviation. The coupling mechanism has two decoupled transmitting coil groups and one receiving coil group. The receiving coil group consists of six identical separate coils connected in series, with adjacent coils wound in opposite directions. Furthermore, this invention proposes a power stabilization control method to resist rotational deviation, enabling stable power transmission at any rotational deviation angle within 0° to 60°, while maintaining high system efficiency.

[0038] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A composite anti-rotation offset method for wireless power transmission systems of underwater vehicles, characterized in that, This composite anti-rotation misalignment method is implemented by an anti-rotation misalignment coupling mechanism and an anti-rotation misalignment power stabilization control unit of an underwater vehicle; The anti-rotation offset coupling mechanism includes two transmitting coil groups and one receiving coil group. The receiving coil group is a ring structure, consisting of six segmented coils connected in series, with adjacent coils having opposite winding directions. The first transmitting coil group and the second transmitting coil group each consist of two coils connected in series, with the two transmitting coils in the same group having the same winding direction. The anti-rotation offset power stabilization control unit includes a primary-side circuit, which consists of a DC power supply, a primary-side controller, a first inverter, a second inverter, a first transmitting coil group, a second transmitting coil group, and a compensation network. The secondary-side circuit consists of a secondary-side coil group, a secondary-side controller, a passive full-bridge rectifier, and a load. The first inverter drives the first transmitting coil group, the second inverter drives the second transmitting coil group, and the primary-side controller adjusts the output voltage phase angle of the first inverter and the second inverter to achieve closed-loop control of the secondary-side output power. The closed-loop control of the secondary-side output power is as follows: the primary-side controller sets the initial phase angle to 90°, the secondary-side controller collects the output power in real time and feeds it back to the primary-side controller via the communication module, and the primary-side controller converts the collected output power value into a single value. P o ( k ) and desired output power P o_ref The output power change rate is obtained by comparing and subtracting. δ ( k ),like δ ( k (lower than) δ ref If, then it ends. δ ( k (Higher than) δ ref Then the phase angle of the first and second inverters controlling the next control cycle decreases by Δ. θ Collect output power P o ( k +1) and calculate the rate of power change. δ ( k +1), if the output power error in the next control cycle δ ( k +1) Output power error compared to the previous control cycle δ ( k If the power change rate is low, continue to decrease the phase angle until it is lower than the threshold value. δ ref If the output power error in the next control cycle δ ( k +1) Output power error compared to the previous control cycle δ ( k If the phase angle of the first and second inverters controlling the next control cycle is large, then the phase angle of the first and second inverters controlling the next control cycle will increase by Δ. θ Collect output power P o ( k +2) and calculate the rate of power change. δ ( k +2), if the output power change rate in the next control cycle is lower than δ ref If, then it ends. δ ( k (Higher than) δ ref Then continue to increase the phase angle until the power change rate is lower than δ ref .

2. The composite anti-rotation offset method for a wireless power transmission system for underwater vehicles according to claim 1, characterized in that, Both transmitting coil groups are solenoid coils with magnetic cores.

3. The composite anti-rotation offset method for a wireless power transmission system for underwater vehicles according to claim 1, characterized in that, The receiving coil assembly is a solenoid coil with a magnetic core.

4. The composite anti-rotation offset method for a wireless power transmission system for underwater vehicles according to claim 1, characterized in that, The six segmented coils in the receiving coil group are of the same size.

5. The composite anti-rotation offset method for a wireless power transmission system for underwater vehicles according to claim 1, characterized in that, The four coils in the transmitting coil assembly are of the same size.

6. The composite anti-rotation offset method for a wireless power transmission system for underwater vehicles according to claim 1, characterized in that, The magnetic fields generated by the two transmitting coil groups are orthogonal to each other and decoupled from each other.

7. The composite anti-rotation offset method for a wireless power transmission system for underwater vehicles according to claim 1, characterized in that, The mutual inductance of the receiving coil group and the two transmitting coil groups compensates for each other to suppress changes in the equivalent total mutual inductance of the coupling mechanism.

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