A resonant temperature drift compensation structure and compensation method suitable for a lunar rover wireless charging system

Abstract

The present invention provides a resonant temperature drift compensation structure and compensation method suitable for a lunar rover wireless charging system. The resonant temperature drift compensation structure comprises a bilateral LCL compensation network, with the coils and compensation inductors at both the transmitting and receiving ends of the network configured as symmetrical structures. Adjustable capacitors are then used to maintain the compensation structure's resonance under large temperature variations. This structure addresses the resonant drift problem of wireless charging systems operating under extreme temperature variations, enabling the system to adapt to the extreme temperature differences between day and night on the moon and operate efficiently and stably.

Description

Technical Field

[0001] The present invention relates to wireless power transmission, and specifically designs a resonant temperature drift compensation structure and compensation method suitable for a wireless charging system of a lunar rover. Background Art

[0002] The lunar rover is a special vehicle that can travel on the lunar surface and complete complex tasks such as lunar exploration, investigation, collection and analysis of samples. It is one of the important tools for lunar surface exploration. The speed of its technological research progress, the degree of functional perfection and the quality of its performance will directly affect the entire process of lunar exploration.

[0003] Current lunar rovers typically rely on solar panels and rechargeable batteries. They rely on the solar cells to operate during the lunar day and then go dormant at night, relying on radioactive isotopes to keep their internal circuits warm until they can resume operations during the day. Therefore, establishing an energy storage base on the moon and ensuring the rover's power supply at night through unmanned wireless charging could significantly increase the rover's operating time and accelerate lunar exploration efforts.

[0004] However, the temperature difference between night and day on the moon is extremely large. The extreme temperature at night can reach -180°C, and the extreme temperature under direct sunlight can reach +150°C. The wireless charging system, as an external facility of the lunar rover, especially the magnetic coupling mechanism, is difficult to keep warm. Under the huge temperature difference between day and night, the coils and compensation components will produce obvious parameter drift, causing system detuning, increasing component stress and reducing system efficiency. Summary of the Invention

[0005] The present invention provides a resonant temperature drift compensation structure and compensation method suitable for a lunar rover wireless charging system, which are used to address the problem of resonant drift of the wireless charging system under conditions of extremely large temperature differences, enabling the wireless charging system to adapt to the conditions of the lunar rover with extremely large temperature differences between day and night, and operate efficiently and stably.

[0006] The present invention is achieved through the following technical solutions:

[0007] A resonant temperature drift compensation structure suitable for a lunar rover wireless charging system includes a bilateral LCL compensation network. The coils and compensation inductors at the transmitting and receiving ends of the bilateral LCL compensation network are configured as symmetrical structures. An adjustable capacitor is then used to adjust and maintain the resonance of the compensation structure under large temperature differences.

[0008] Furthermore, the coils at the transmitting end and the receiving end are not required to be exactly the same, but the compensating inductor at the transmitting end and the transmitting coil are symmetrical with respect to the magnetic material and the shielding layer of the transmitting end, and the compensating inductor at the receiving end and the receiving coil are symmetrical with respect to the magnetic material and the shielding layer of the receiving end, and the self-inductance magnetic path of the compensating inductor and the coil are required to be the same.

[0009] Furthermore, under the action of magnetic materials and shielding materials, there is basically no cross-coupling between the coil and the compensation inductor. The compensation inductor only compensates for the temperature parameters of the compensation network and does not participate in the magnetic field coupling energy transmission, so that the compensation structure still maintains constant current output and load coupling resonance-independent characteristics.

[0010] Furthermore, the capacitors at the transmitting end and the receiving end of the compensation structure are both adjustable capacitors.

[0011] A control method for a resonant temperature drift compensation structure suitable for a lunar rover wireless charging system, the control method comprising:

[0012] First, the receiving-end power converter is locked in the short-circuit mode, and the transmitting-end power converter starts low-power excitation;

[0013] Detect the receiving end coil current, and adjust the receiving end adjustable capacitor to minimize the coil current by using the disturbance observation method. At this time, the receiving end coil capacitance value is locked, and the receiving end power converter is adjusted to normal working mode.

[0014] The compensation structure is normally input, and the adjustable capacitance value of the transmitter is adjusted to make the output voltage and output current of the transmitter power converter in phase, and normal charging is started. When charging is completed, the system is powered off.

[0015] Furthermore, when the compensation structure is constructed,

[0016] The symmetrical integrated magnetic coupling mechanism can select a circular coil, and the compensation inductor is made into the same structure as the energy transmission coil. The shielding aluminum plate can be omitted. The compensation inductor is symmetrically placed on the other side of the magnetic material so that it maintains basically the same parameters as the energy transmission coil at different temperatures; then, an LCL-type compensation network is established, and the capacitor is designed as an adjustable capacitor; finally, the power converter and power battery of the transmitting and receiving ends are connected to complete the construction of the compensation structure.

[0017] Furthermore, the compensation structure needs to be based on a bilateral LCL type compensation network, with the transmitter compensation inductor L f1 and the transmitting coil self-inductance L p Equal, the receiving end compensation inductor L f2 and the receiving coil self-inductance L s The parallel capacitors at the transmitting and receiving ends resonate with the compensating inductors at the transmitting and receiving ends respectively. The specific tuning method is shown in formula (1):

[0018]

[0019] Where ω=2πf is the system operating angular frequency, and f is the system operating frequency.

[0020] Furthermore, the adjustable capacitor can be composed of two anti-parallel MOSFETs and a fixed capacitor. By reasonably configuring the driving signals of the two MOSFETs within the excitation current cycle of the capacitor, the overall equivalent capacitance of the switching capacitor changes, and its equivalent capacitance value is adjusted by the duty cycle of the PWM driving signal.

[0021] The beneficial effects of the present invention are:

[0022] The resonant temperature drift compensation structure and control method for a lunar rover wireless charging system described in the present invention enable the wireless charging system to effectively cope with the temperature drift of compensation component parameters caused by drastic temperature changes during the day and night on the moon, ensure the load-independent resonance of the system, and guarantee the transmission power and transmission efficiency under harsh working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the resonant temperature drift compensation structure of the wireless charging system of the present invention.

[0024] Figure 2 This is a schematic diagram of the magnetic field line distribution of the symmetrical integrated magnetic coupling mechanism of the present invention.

[0025] Figure 3 This is a diagram of a switch adjustable capacitor and its control waveform of the present invention.

[0026] Figure 4 It is a flow chart of the resonance adjustment method of the present invention. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0028] A resonant temperature drift compensation structure suitable for a lunar rover wireless charging system, the resonant temperature drift compensation structure comprising a bilateral LCL type compensation network,

[0029] The transmitter compensation inductor and the transmitter coil are symmetrical about the transmitter magnetic material and shielding layer, and the receiver compensation inductor and the receiver coil are symmetrical about the receiver magnetic material and shielding layer. The self-inductance magnetic paths of the compensation inductor and the coil are required to be the same. Under this condition, the compensation inductor and the coil will show the same self-inductance value under the same temperature conditions, and the two will always remain basically equal as the ambient temperature changes, maintaining the basic resonant condition of the LCL compensation network. Figure 2As shown in the figure, under the action of the magnetic material, there is basically no cross coupling between the coil and the compensation inductor. The compensation inductor is only used to compensate the temperature parameters of the compensation network and does not participate in the magnetic field coupling energy transmission, so that the compensation structure still maintains the constant current output and load coupling resonance-independent characteristics of the LCL compensation network.

[0030] Furthermore, the compensation structure is based on a bilateral LCL type compensation network, wherein the transmitter compensation inductor L f1 and the transmitting coil self-inductance L p Equal, the receiving end compensation inductor L f2 and the receiving coil self-inductance L s The parallel capacitors at the transmitting and receiving ends resonate with the compensating inductors at the transmitting and receiving ends respectively. The specific tuning method is shown in formula (1):

[0031]

[0032] Where ω=2πf is the system operating angular frequency, and f is the system operating frequency. Furthermore, during the system construction process:

[0033] The symmetrical integrated magnetic coupling mechanism selects a circular coil, makes the compensation inductor into the same structure as the energy transmission coil, does not use a shielding aluminum plate, and symmetrically places the compensation inductor on the other side of the magnetic material so that it maintains basically the same parameters as the energy transmission coil at different temperatures; then establishes an LCL type compensation network, and designs the capacitor as follows Figure 3 The adjustable capacitor shown in the figure; finally, connect the power converter and power battery of the transmitting and receiving ends to complete the compensation structure.

[0034] Furthermore, the adjustable capacitor can be Figure 3 The circuit shown consists of two anti-parallel MOSFETs and a fixed capacitor. By properly configuring the driving signals of the two MOSFETs within the excitation current cycle of the capacitor, the overall equivalent capacitance of the switched capacitor changes, and its equivalent capacitance value is adjusted by the duty cycle of the PWM driving signal.

[0035] Furthermore, during the operation of the system, the coil inductance and capacitance values will drift significantly with the change of day and night temperature. In this scenario, resonance control adjustment is required every time charging is started, such as Figure 4 As shown, the control method is as follows:

[0036] First, the receiving-end power converter is locked in the short-circuit mode, and the transmitting-end power converter starts low-power excitation;

[0037] Detect the receiving end coil current, and adjust the receiving end adjustable capacitor to minimize the coil current by using the disturbance observation method. At this time, the receiving end coil capacitance value is locked, and the receiving end power converter is adjusted to normal working mode.

[0038] The compensation structure is normally input, and the adjustable capacitance value of the transmitter is adjusted to make the output voltage and output current of the transmitter power converter in phase, and normal charging is started. After charging is completed, the system is powered off.

Claims

1. A control method for a resonant temperature drift compensation structure suitable for a lunar rover wireless charging system, characterized in that: The resonant temperature drift compensation structure includes a bilateral LCL compensation network, and the coils and compensation inductors at the transmitting end and the receiving end of the bilateral LCL compensation network are set to a symmetrical structure, and then the resonance of the compensation structure under large temperature difference changes is adjusted by an adjustable capacitor. The coils at the transmitting end and the receiving end do not require the transmitting coil to be exactly the same as the receiving coil, but the transmitting end compensation inductor and the transmitting coil are symmetrical with respect to the transmitting end magnetic material and the shielding layer, and the receiving end compensation inductor and the receiving coil are symmetrical with respect to the receiving end magnetic material and the shielding layer. The self-inductance magnetic path of the compensation inductor and the coil is required to be the same. Under the action of the magnetic material and the shielding material, there is basically no cross-coupling between the coil and the compensation inductor. The compensation inductor is only used to compensate for the temperature parameters of the compensation network and does not participate in the magnetic field coupling energy transmission, so that the compensation structure still maintains constant current output and load coupling resonance-independent characteristics. The capacitors at the transmitting end and the receiving end of the compensation structure both use adjustable capacitors; The control method includes First, the receiving-end power converter is locked in the short-circuit mode, and the transmitting-end power converter starts low-power excitation; Detect the receiving end coil current, and adjust the receiving end adjustable capacitor to minimize the coil current by using the disturbance observation method. At this time, the receiving end coil capacitance value is locked, and the receiving end power converter is adjusted to normal working mode. The compensation structure is normally input, and the adjustable capacitance value of the transmitter is adjusted to make the output voltage and output current of the transmitter power converter in phase, and normal charging is started. After charging is completed, the system is powered off.

2. The control method for a resonant temperature drift compensation structure for a lunar rover wireless charging system according to claim 1, characterized in that: When the resonant temperature drift compensation structure is constructed, A circular coil is selected for the symmetrical integrated magnetic coupling mechanism, and the compensation inductor is made into the same structure as the energy transmission coil. No shielding aluminum plate is used, and the compensation inductor is symmetrically placed on one side of the magnetic material so that it maintains basically the same parameters as the energy transmission coil at different temperatures. Then, an LCL-type compensation network is established, and the capacitor is designed as an adjustable capacitor. Finally, the power converter and power battery of the transmitting and receiving ends are connected to complete the construction of the compensation structure.

3. The control method for a resonant temperature drift compensation structure for a lunar rover wireless charging system according to claim 1, characterized in that: The resonant temperature drift compensation structure is based on a bilateral LCL type compensation network, and its transmitter compensation inductor L f1 Self-inductance of the transmitting coil L p Equal, receiving end compensation inductance L f2 and the receiving coil self-inductance L s The parallel capacitors at the transmitting and receiving ends resonate with the compensating inductors at the transmitting and receiving ends respectively. The specific tuning method is shown in formula (1): (1) In the formula ω =2 πf is the system operating angular frequency, f is the system operating frequency.

4. The control method for a resonant temperature drift compensation structure for a lunar rover wireless charging system according to claim 1, characterized in that: The adjustable capacitor consists of two anti-parallel MOSFETs and a fixed capacitor. By reasonably configuring the driving signals of the two MOSFETs within the excitation current cycle of the capacitor, the overall equivalent capacitance of the switching capacitor changes, and its equivalent capacitance value is adjusted by the duty cycle of the PWM driving signal.

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