Photo-thermal coupling self-powered tracking driving system

Abstract

The invention discloses a photo-thermal coupling self-powered tracking driving system, relates to the technical field of photovoltaic power generation, and solves the problems of energy consumption waste and use limitation in the prior art. The thermoelectric conversion module generates power by utilizing the temperature difference between waste heat generated by the photovoltaic panel in an illumination working state and the environment, the photovoltaic panel and the thermoelectric conversion module are electrically connected with the hybrid energy storage unit, and the hybrid energy storage unit comprises a capacitor and a rechargeable battery which are connected in parallel; the energy management controller is electrically connected with the photovoltaic panel, the thermoelectric conversion module and the hybrid energy storage unit and used for collecting the environment illumination intensity, the electric quantity state of the battery and the terminal voltage of the capacitor and generating a control instruction based on collected signals, and the driving mechanism is connected with the energy management controller and used for driving the hybrid energy storage unit to work. And driving the photovoltaic panel to adjust the azimuth angle and / or the elevation angle in response to the control instruction so as to perform sun tracking motion. The use adaptability is improved, and energy waste is reduced.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power generation technology, and in particular to a photothermal coupling self-powered tracking drive system. Background Technology

[0002] To improve power generation efficiency, existing photovoltaic (PV) tracking systems use drive mechanisms and central controllers to dynamically adjust the angle of the modules. However, their operation is highly dependent on external grid power, with their own energy consumption reaching 3%–8% of the system's power generation. In off-grid or unstable grid areas, such systems are difficult to deploy and require additional wiring, increasing costs and safety risks, and limiting the widespread application of tracking technology. Meanwhile, PV panels generate a large amount of waste heat during operation due to photothermal conversion, with surface temperatures often 20°C–30°C higher than the ambient temperature, resulting in a decrease in photoelectric efficiency of 8%–12%. Existing tracking systems neither recover this waste heat for energy supply nor improve electrical performance through thermal management, resulting in a dual energy loss of both power consumption and thermal waste, leading to serious deficiencies in overall energy efficiency and environmental adaptability. Summary of the Invention

[0003] The purpose of this invention is to provide a photothermal coupling self-powered tracking drive system, which solves the problems of energy waste and limited use in the prior art, improves the adaptability of use and reduces energy waste.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a photothermal coupling self-powered tracking drive system, comprising a photovoltaic panel, a thermoelectric conversion module, a hybrid energy storage unit, an energy management controller, and a drive mechanism. The thermoelectric conversion module is disposed on the back side of the photovoltaic panel. The thermoelectric conversion module generates electricity by utilizing the temperature difference between the waste heat generated by the photovoltaic panel under sunlight and the environment. The photovoltaic panel and the thermoelectric conversion module are electrically connected to the hybrid energy storage unit, which includes a capacitor and a rechargeable battery connected in parallel. The energy management controller is electrically connected to the photovoltaic panel, the thermoelectric conversion module, and the hybrid energy storage unit, and is used to collect ambient light intensity, the battery's charge state, and the capacitor's terminal voltage, and generate control commands based on the collected signals. The drive mechanism is connected to the energy management controller and, in response to the control commands, drives the photovoltaic panel to adjust its azimuth and / or elevation angles for solar tracking.

[0005] After adopting the above technical solution, the present invention has the following advantages: By integrating a thermoelectric conversion module on the back panel of the photovoltaic panel, the drive system can generate electricity by utilizing the temperature difference between the photovoltaic panel and the environment when the photovoltaic panel is working. In this process, heat is conducted from the photovoltaic panel to its cold end through the thermoelectric conversion module and dissipated into the environment. The thermoelectric effect simultaneously converts some of the heat energy into electrical energy, which not only recovers the waste heat that was originally wasted, but also objectively suppresses the temperature rise of the photovoltaic panel because the heat is continuously discharged, which helps to maintain a high photoelectric conversion efficiency. The generated electricity and the output of the photovoltaic panels are connected together to a hybrid energy storage unit consisting of capacitors and rechargeable batteries in parallel. The capacitors, with their high power density, can instantly release large currents to meet the peak power required for the start-up and operation of the drive mechanism. The batteries, on the other hand, store energy over a longer timescale, ensuring the drive system retains basic operational capabilities even under adverse conditions such as low light, nighttime, or continuous cloudy days. This synergy enhances the dynamic response and duration of power supply, thereby minimizing the dependence on external power supply and the costs and safety hazards associated with wiring, as is common in traditional tracking systems. Simultaneously, it converts previously wasted heat energy into usable work, significantly improving overall energy efficiency and environmental adaptability, making photovoltaic tracking technology more widely applicable in off-grid and grid-weak areas. The energy management controller dynamically determines whether to output drive commands based on the collected ambient light intensity, battery state of charge, and capacitor terminal voltage, enabling the drive system to perform solar tracking without external grid power, further improving the applicability of photovoltaic tracking technology in off-grid and grid-weak areas.

[0006] Furthermore, the operating mode of the drive mechanism includes a first operating mode: when the ambient light intensity is greater than a first threshold and the battery charge level is higher than a second threshold, the drive mechanism performs solar tracking motion with a first angular resolution.

[0007] Second operating mode: When the ambient light intensity is between the third threshold and the first threshold, and the battery charge level is between the fourth threshold and the second threshold, the drive mechanism performs solar tracking motion with a second angular resolution.

[0008] The third operating mode is activated when the ambient light intensity is less than the fifth threshold or the battery charge level is lower than the sixth threshold, and the drive mechanism stops the solar tracking movement.

[0009] Wherein, the second angular resolution is lower than the first angular resolution, the first threshold is greater than the third threshold, the second threshold is greater than the fourth threshold, the third threshold is greater than the fifth threshold, and the fourth threshold is greater than the sixth threshold.

[0010] By adopting the aforementioned technical solution, multi-level operating modes are set, and the tracking strategy is dynamically adjusted based on the combination of real-time ambient light intensity and battery charge status. This achieves a better balance between power generation revenue and energy consumption while ensuring the energy sustainability of the drive system. When sunlight is sufficient and energy storage is abundant, the drive system uses a high-precision first angular resolution for fine tracking to maximize the capture of solar radiation. When sunlight or energy storage levels are moderate, it switches to a lower-precision second angular resolution to reduce drive frequency and energy consumption while maintaining effective tracking. When sunlight is extremely weak or energy storage is severely insufficient, the drive system actively stops tracking to avoid unnecessary energy consumption and power depletion. A clear hierarchical relationship is established between the thresholds, minimizing the problems of insufficient accuracy under sufficient sunlight or excessive energy consumption under insufficient sunlight in a single fixed mode. This ensures clear boundaries and hysteresis characteristics for mode switching, thereby preventing frequent start-stops or mode oscillations due to environmental fluctuations. It also gives the drive system stronger adaptability and operational robustness in complex and ever-changing off-grid environments, thus balancing tracking performance, energy efficiency, and long-term reliability without relying on an external power grid.

[0011] Furthermore, the first angular resolution is ±0.1°, and the second angular resolution is ±1°.

[0012] By adopting the aforementioned technical solution, under high-yield operating conditions with strong sunlight and sufficient energy storage, a higher precision tracking of ±0.1° is used, enabling the photovoltaic panel to be aligned with the sun's position almost in real time, minimizing the incident angle deviation, and thus significantly improving the light capture efficiency. Under medium operating conditions with weak sunlight or limited energy storage, switching to a lower precision tracking of ±1°, although sacrificing a small amount of optical gain, greatly reduces the adjustment frequency and stroke of the drive mechanism, effectively reducing drive energy consumption and avoiding energy redundancy caused by high precision tracking as much as possible.

[0013] Furthermore, when switching from the third operating mode to the first or second operating mode, the energy management controller controls the drive mechanism to first perform a coarse positioning operation before entering the corresponding target operating mode.

[0014] Through the above technical solution, since the third operating mode usually occurs at night, during continuous cloudy days, or when the power is low, the angle of the photovoltaic panel remains stationary while the azimuth and elevation angle of the sun have changed significantly. If tracking is started directly with high precision or conventional resolution, the drive mechanism may need to make multiple adjustments to approach the actual sun position. This is not only time-consuming and energy-intensive, but may also result in insufficient light to maintain operation due to excessive initial deviation. By performing a fast, large-step coarse positioning in advance, the drive system can quickly adjust the photovoltaic panel to a range close to the optimal orientation, laying the foundation for subsequent fine tracking with high or medium angular resolution. This allows for a faster recovery of high-efficiency power generation, improved energy recovery efficiency, and reduced ineffective energy consumption caused by blind fine-tuning. Furthermore, it enhances the response speed and self-recovery capability of the drive system under intermittent operating conditions.

[0015] Furthermore, the coarse positioning operation includes: estimating the current solar azimuth angle based on real-time clock signals and pre-stored geographical location information using a solar position algorithm, and controlling the drive mechanism to rotate the photovoltaic panel to a predetermined angle deviation range of the solar azimuth angle.

[0016] By adopting the aforementioned technical solution, using a real-time clock and pre-stored geographical location information, the current solar azimuth angle is directly calculated through a solar position algorithm. In the absence of light or sensor failure, a global and deterministic angle reference can be obtained without any external light signal input. Based on this, the controller drives the photovoltaic panel to rotate to a preset tolerance range near the theoretical solar azimuth in one go, avoiding all trial and error actions as much as possible and significantly reducing the energy consumption during the wake-up phase.

[0017] Furthermore, in the first or second operating mode, the energy management controller prioritizes using the capacitor to supply power to the drive mechanism. In the third operating mode, the energy management controller controls the battery to supply power to the drive mechanism.

[0018] Through the above technical solution, in the first or second operating mode, the drive mechanism needs to start and stop frequently or make fine-tuning of the angle, and the instantaneous power demand is high. At this time, the energy management controller prioritizes the use of capacitor power supply, and utilizes its high power density and fast discharge characteristics to efficiently meet the peak current required for the start-up and dynamic adjustment of the drive mechanism, and avoids the battery from aging rapidly or voltage dropping suddenly due to high current pulse discharge as much as possible. In the third operating mode, the drive mechanism is in a standby maintenance state, with a lower frequency of operation and lower power demand, but the duration may be longer. Its high energy density characteristics can be fully utilized to provide stable energy output, which solves the inherent contradiction between power response speed and energy density of a single energy storage element.

[0019] Furthermore, the energy management controller replenishes the capacitor via the battery.

[0020] Through the above technical solution, the stable energy stored in the battery can be utilized to actively maintain the usable voltage level of the capacitor during periods of intermittent sunlight, at night, or under low light conditions, ensuring that it always has the ability to respond to the next high-power drive command. At the same time, the recharging process is intelligently triggered by the energy management controller based on the capacitor terminal voltage and battery charge status, and is only executed when the capacitor voltage is below a set threshold and the battery charge is sufficient. This avoids unnecessary energy conversion losses as much as possible and prevents the battery from being over-discharged. As a result, a synergistic relationship is formed between the capacitor and the battery, with the battery providing energy storage and the capacitor releasing energy instantaneously, enabling the hybrid energy storage unit to achieve efficient division of labor between dynamic load and static reserve.

[0021] Furthermore, the energy management controller controls the steady-state electrical energy output by the photovoltaic panel or the steady-state electrical energy output by the thermoelectric conversion module to be stored in the battery, and the energy management controller controls the transient electrical energy output by the photovoltaic panel or the transient electrical energy output by the thermoelectric conversion module to be stored in the capacitor.

[0022] Through the above technical solutions, steady-state electrical energy typically manifests as a continuous and smooth power output, such as the stable power generation of photovoltaic panels on sunny days or the continuous power supply of thermoelectric modules when the temperature difference between the photovoltaic backsheet and the environment is maintained during the day. This type of energy is more suitable for replenishing batteries because it has a high energy density and low self-discharge, and can be stored for a long time to support the basic operation of the system during periods of no sunlight or low temperature difference. Transient electrical energy, on the other hand, manifests as short-duration, highly volatile power pulses, such as photovoltaic output spikes caused by a sudden increase in cloud gap light, or instantaneous voltage rises in thermoelectric modules caused by sudden temperature changes. If this type of energy is directly charged into batteries, it is not only difficult to absorb effectively due to the slow response speed of the batteries, but it may also affect their lifespan due to current surges. However, capacitors, with their extremely high charge and discharge rates and cycle stability, can efficiently capture and temporarily store these short-lived energy pulses. Through real-time discrimination and shunt control of power output characteristics by the energy management controller, the system avoids energy waste and improves the utilization efficiency of irregular and intermittent electrical energy, such as that obtained from waste heat recovery.

[0023] Furthermore, a heat-conducting layer is provided between the thermoelectric conversion module and the back plate of the photovoltaic panel.

[0024] The above technical solutions ensure that the waste heat generated by the photovoltaic panel during operation can be quickly and with low resistance conducted to the hot end of the thermoelectric conversion module, enabling the thermoelectric conversion module to more accurately and fully sense and utilize the operating temperature rise of the photovoltaic panel.

[0025] Furthermore, the thermoelectric conversion module has multiple heat dissipation fins spaced apart on the side away from the photovoltaic panel.

[0026] With the above technical solution, the thermoelectric conversion efficiency directly depends on the temperature difference. If the cold end heat dissipation is poor, heat will accumulate inside the thermoelectric conversion module, causing the cold end temperature to rise rapidly and the temperature difference to decrease. This not only significantly reduces the power generation output but may also weaken the cooling effect on the photovoltaic panel. However, by arranging reasonably spaced heat dissipation fins at the cold end, the heat exchange area in contact with the air is significantly increased, and natural convection (or enhanced forced convection under windy conditions) is used to accelerate the diffusion of heat to the environment, making the cold end temperature as close as possible to the ambient temperature. This passive heat dissipation structure requires no additional energy consumption but can continuously and stably increase the operating temperature difference of the thermoelectric module, thereby improving the waste heat recovery efficiency. At the same time, good cold end heat dissipation also indirectly enhances the driving force for heat conduction from the photovoltaic panel through the thermoelectric module to the environment, further assisting in reducing the operating temperature of the photovoltaic panel, forming a positive cycle of efficient heat dissipation—greater temperature difference—more power generation—stronger cooling. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings:

[0028] Figure 1 This is a diagram of the photothermal coupling self-powered tracking drive system of the present invention;

[0029] Figure 2 This is a schematic diagram of the thermoelectric conversion module of the present invention;

[0030] Figure 3 This is a schematic diagram of the power supply for the tracking system of the present invention;

[0031] Figure 4 This is a schematic diagram of the photothermal coupling self-powered tracking drive system of the present invention;

[0032] In the diagram, 10 is the photovoltaic panel; 20 is the thermoelectric conversion module; 21 is the cold end; 22 is the hot end; 30 is the hybrid energy storage unit; 31 is the capacitor; 32 is the battery; 33 is the DC-DC converter; 40 is the energy management controller; 50 is the drive mechanism; 60 is the light sensor; and 70 is the voltage sampling circuit. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, and not all embodiments.

[0034] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein.

[0035] It should be understood that in the various embodiments of the present invention, the number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0036] It should be understood that in this invention, "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0037] It should be understood that in this invention, "multiple" refers to two or more. "And / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, X and / or Y can represent: X alone, X and Y simultaneously, or Y alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "Contains X, Y, and Z", "Contains X, Y, and Z" means that all three X, Y, and Z are contained; "Contains X, Y, or Z" means that one of X, Y, and Z is contained; "Contains X, Y, and / or Z" means that any one, two, or three of X, Y, and Z are contained.

[0038] The technical solution of the present invention will be described in detail below with reference to specific embodiments. The following specific embodiments may be combined or substituted with each other according to the actual situation, and the same or similar concepts or processes may not be described again in some embodiments.

[0039] like Figures 1 to 4As shown, this invention provides a photothermal coupling self-powered tracking drive system, including a photovoltaic panel 10, a thermoelectric conversion module 20, a hybrid energy storage unit 30, an energy management controller 40, and a drive mechanism 50. The thermoelectric conversion module 20 is located on the back panel side of the photovoltaic panel 10. The thermoelectric conversion module 20 includes a hot end 22 near the back panel side of the photovoltaic panel 10 and a cold end 21 away from the hot end 22. The thermoelectric conversion module 20 generates electricity by utilizing the temperature difference between the waste heat generated by the photovoltaic panel 10 under sunlight and the environment. The photovoltaic panel 10 and the thermoelectric conversion module 20... The photovoltaic panel 10, the thermoelectric conversion module 20, and the hybrid energy storage unit 30 are electrically connected to each other. The hybrid energy storage unit 30 includes a capacitor 31 and a rechargeable battery 32 connected in parallel. The energy management controller 40 is electrically connected to the photovoltaic panel 10, the thermoelectric conversion module 20, and the hybrid energy storage unit 30. It is used to collect ambient light intensity, the charge status of the battery 32, and the terminal voltage of the capacitor 31, and generate control commands based on the collected signals. The drive mechanism 50 is connected to the energy management controller 40 and drives the photovoltaic panel 10 to adjust the azimuth angle and / or elevation angle in response to the control commands to perform solar tracking.

[0040] By integrating a thermoelectric conversion module 20 on the back panel side of the photovoltaic panel 10, the drive system can generate electricity by utilizing the temperature difference between the photovoltaic panel 10 and the environment when the photovoltaic panel 10 is working. During this process, heat is conducted from the photovoltaic panel 10 to its cold end 21 via the thermoelectric conversion module 20 and dissipated into the environment. The thermoelectric effect simultaneously converts some of the heat energy into electrical energy, which not only recovers the waste heat that was originally wasted, but also objectively suppresses the temperature rise of the photovoltaic panel 10 due to the continuous removal of heat, thus helping to maintain a high photoelectric conversion efficiency. The generated power and the output of the photovoltaic panel 10 are connected together to a hybrid energy storage unit 30, which consists of a capacitor 31 and a rechargeable battery 32 connected in parallel. The capacitor 31 has high power density characteristics and can release a large current instantaneously to meet the peak power required for the start-up and operation of the drive mechanism 50. The battery 32 is responsible for storing energy over a longer time scale, ensuring that the drive system retains basic operational capabilities under adverse conditions such as low light, nighttime, or continuous cloudy days. The two work together to improve the dynamic response capability and time continuity of the power supply, thereby minimizing the dependence of traditional tracking systems on external power supply, the cost and safety hazards caused by wiring, and converting previously wasted heat energy into useful work, significantly improving the overall energy utilization efficiency and environmental adaptability, and making photovoltaic tracking technology more widely applicable in off-grid and grid-weak areas. The energy management controller 40 dynamically determines whether to output drive commands based on the collected ambient light intensity, the charge status of the battery 32, and the terminal voltage of the capacitor 31, enabling the drive system to complete solar tracking without external grid power supply, further improving the application feasibility of photovoltaic tracking technology in off-grid and grid-weak areas.

[0041] It should be noted that the drive system collects ambient light intensity in real time through the light sensor 60 and transmits the signal to the energy management controller 40. The remaining state of charge of the battery 32 is estimated based on its terminal voltage. The terminal voltage of the capacitor 31 is collected through a resistor voltage divider sampling circuit 70. The acquired voltage signal is converted from analog to digital and then input to the energy management controller 40 for operation mode determination and drive decision-making. The electrical energy output from the photovoltaic panel 10 is optimized by the MPPT controller and then input to the hybrid energy storage unit 30. The electrical energy output from the thermoelectric conversion unit needs to be boosted to 5V by the DC-DC converter 33 before it can be input to the hybrid energy storage unit 30. The drive mechanism 50 includes an azimuth adjustment component and an elevation adjustment component, both of which employ a geared motor in conjunction with a worm gear or lead screw and nut transmission mechanism. The output shaft of the azimuth adjustment component is connected to the column of the photovoltaic panel 10 support, and is used to drive the photovoltaic panel 10 to rotate in the horizontal plane to track the solar azimuth angle. One end of the elevation adjustment component is hinged to the bottom of the column, and the other end is connected to the back plate of the photovoltaic panel 10. It changes the angle between the photovoltaic panel 10 and the ground plane through push-pull motion to track the solar elevation angle. The energy management controller 40 generates PWM control commands based on the solar position algorithm or the photosensitive sensor signal, and drives the two geared motors to rotate in both directions, thereby achieving a more accurate tracking motion of the photovoltaic panel 10 in the azimuth and / or elevation directions.

[0042] In this application, the air gap or surface roughness between the thermoelectric conversion module 20 and the back panel of the photovoltaic panel 10 will create significant thermal resistance, causing the temperature of the hot end 22 of the thermoelectric module to be much lower than the actual temperature of the photovoltaic back panel. This significantly reduces the usable temperature difference, thereby reducing the thermoelectric power output or even rendering it ineffective. To address this, a thermally conductive layer is provided between the thermoelectric conversion module 20 and the back panel of the photovoltaic panel 10. The thermally conductive layer can be made of materials such as thermal grease, thermal pads, or metal-based thermal interface materials. This not only fills the microscopic gaps on the contact surface and reduces the interface thermal resistance, but also improves the uniformity and stability of heat transfer. This ensures that the waste heat generated by the photovoltaic panel 10 during operation can be quickly and with low resistance conducted to the hot end 22 of the thermoelectric conversion module 20, allowing the thermoelectric conversion module 20 to more accurately and fully perceive and utilize the operating temperature rise of the photovoltaic panel 10. As a result, under the same environmental and light conditions, the thermoelectric output power is maximized, and the photovoltaic panel 10 achieves a more effective passive cooling effect due to the efficient heat dissipation, further mitigating the photoelectric efficiency degradation caused by high temperatures.

[0043] Since the thermoelectric conversion efficiency directly depends on the temperature difference, if the cold end 21 has poor heat dissipation, heat will accumulate inside the thermoelectric conversion module 20, causing the temperature of the cold end 21 to rise rapidly and the temperature difference to decrease. This not only significantly reduces the power generation output but may also weaken the cooling effect on the photovoltaic panel 10. Therefore, in this application, multiple heat dissipation fins are spaced apart on the side of the thermoelectric conversion module 20 away from the photovoltaic panel 10, i.e., they are located at the cold end 21. This significantly increases the heat exchange area in contact with the air and utilizes natural convection (or enhanced forced convection under windy conditions) to accelerate the diffusion of heat to the environment, making the temperature of the cold end 21 as close as possible to the ambient temperature. This passive heat dissipation structure requires no additional energy consumption but can continuously and stably increase the operating temperature difference of the thermoelectric module, thereby improving the waste heat recovery efficiency. At the same time, good heat dissipation at the cold end 21 also indirectly enhances the driving force for heat conduction from the photovoltaic panel 10 through the thermoelectric module to the environment, further assisting in reducing the operating temperature of the photovoltaic panel 10, forming a positive cycle of efficient heat dissipation—greater temperature difference—more power generation—stronger cooling. Of course, in other embodiments, the heat dissipation device can be heat pipes, vapor chambers, micro fans, phase change material heat dissipation layers, graphene thermal conductive films, microchannel liquid cooling plates, or any combination of two or more of the above structures, in addition to heat dissipation fins. For example, heat pipes can be embedded inside the heat dissipation fins to improve the lateral heat diffusion capability, or a low-power micro fan powered by the hybrid energy storage unit 30 can be installed in high-irradiation areas to achieve controllable air cooling; in space-constrained scenarios, graphene films with high thermal conductivity can be used to replace traditional metal fins to reduce weight and improve in-plane thermal uniformity; and in areas with large day-night temperature differences, the characteristics of phase change materials absorbing heat during the day and releasing heat at night can be combined to smooth out temperature fluctuations at the cold end 21 and maintain a more stable temperature difference output as much as possible. The above alternative or combined solutions are all aimed at enhancing the heat dissipation performance of the cold end 21 of the thermoelectric conversion module 20, and ensuring that the system maintains efficient photothermal synergistic operation capability under different climate and installation conditions as much as possible.

[0044] The electrical energy output by the photovoltaic panel 10 or the thermoelectric conversion module 20 typically exists in two forms: steady-state electrical energy and transient electrical energy. Steady-state electrical energy is usually characterized by continuous and gradual power output, such as the stable power generation of the photovoltaic panel 10 on sunny days or the continuous power supply of the thermoelectric module when the photovoltaic backsheet and the environment maintain a temperature difference during the day. Transient electrical energy, on the other hand, is characterized by short-duration and highly volatile power pulses, such as the photovoltaic output spike caused by a sudden increase in cloud gap light, or the instantaneous voltage rise of the thermoelectric module caused by a sudden temperature change. If this type of energy is directly charged into the battery 32, it will not only be difficult to absorb effectively due to the slow response speed of the battery 32, but its lifespan may also be affected by the current surge. Therefore, in this application, the energy management controller... The energy management controller 40 controls the steady-state electrical energy output from the photovoltaic panel 10 or the thermoelectric conversion module 20 to be stored in the battery 32. This allows for long-term storage to support the basic operation of the system during periods without sunlight or with low temperature differences. The energy management controller 40 also controls the transient electrical energy output from the photovoltaic panel 10 or the thermoelectric conversion module 20 to be stored in the capacitor 31. With the high charging and discharging rate and cycle stability of the capacitor 31, these short-lived energy pulses can be efficiently captured and temporarily stored. Thus, through the real-time discrimination and diversion control of the power output characteristics by the energy management controller 40, the drive system avoids energy waste as much as possible and improves the utilization efficiency of irregular and intermittent electrical energy such as that obtained from waste heat recovery.

[0045] To further reduce energy consumption, the operating modes of the drive mechanism 50 include a first operating mode: when the ambient light intensity is greater than a first threshold and the charge state of the battery 32 is higher than a second threshold, the drive mechanism 50 performs solar tracking motion with a first angular resolution.

[0046] Second operating mode: When the ambient light intensity is between the third threshold and the first threshold, and the battery 32's charge state is between the fourth threshold and the second threshold, the drive mechanism 50 performs solar tracking motion with a second angular resolution.

[0047] Third operating mode: When the ambient light intensity is less than the fifth threshold or the battery 32's charge level is lower than the sixth threshold, the drive mechanism 50 stops the solar tracking motion;

[0048] Among them, the second angular resolution is lower than the first angular resolution, the first threshold is greater than the third threshold, the second threshold is greater than the fourth threshold, the third threshold is greater than the fifth threshold, and the fourth threshold is greater than the sixth threshold.

[0049] By setting multiple operating modes, the tracking strategy is dynamically adjusted based on the combination of real-time ambient light intensity and battery charge status, achieving a fine balance between power generation revenue and energy consumption while ensuring the energy sustainability of the drive system. When sunlight is sufficient and energy storage is abundant, the system uses a high-precision first-angle resolution for fine tracking to maximize solar radiation capture. When sunlight or energy storage levels are moderate, it switches to a lower-precision second-angle resolution to reduce drive frequency and energy consumption while maintaining effective tracking. When sunlight is extremely weak or energy storage is severely insufficient, the system actively stops tracking to avoid unnecessary energy consumption and power depletion. A clear hierarchical relationship is established between the thresholds to avoid insufficient accuracy under sufficient sunlight or excessive energy consumption under insufficient sunlight in a single fixed mode. This ensures clear boundaries and hysteresis characteristics for mode switching, preventing frequent start-stops or mode oscillations due to environmental fluctuations. It also gives the system stronger adaptability and operational robustness in complex and changing off-grid environments, thus balancing tracking performance, energy efficiency, and long-term reliability without relying on an external power grid.

[0050] It should be noted that the drive system does not completely shut down in the third motion mode; the sensing functions of each sensor must still be maintained. Specifically, the first threshold can be 80,000 lux, the second threshold can be 80%, the third threshold can be 40,000 lux, the fourth threshold can be 50%, the fifth threshold can be 20,000 lux, and the sixth threshold can be 30%.

[0051] In high-yield operating conditions with strong sunlight and sufficient energy storage, the first angular resolution is ±0.1°, enabling the photovoltaic panel 10 to be aligned with the sun almost in real time, minimizing the incident angle deviation and thus significantly improving the light capture efficiency. In medium operating conditions with weak sunlight or limited energy storage, the second angular resolution is ±1°. Although a small amount of optical gain is sacrificed, the adjustment frequency and stroke of the drive mechanism 50 are greatly reduced, effectively reducing drive energy consumption and minimizing energy redundancy caused by high-precision tracking.

[0052] Since the third operating mode usually occurs at night, during continuous cloudy days, or when the power is low, the photovoltaic panel 10 remains stationary while the sun's azimuth and elevation angles have changed significantly. If tracking is started directly with high precision or conventional resolution, the drive mechanism 50 may need to make multiple small adjustments to approach the actual sun position. This is not only time-consuming and energy-intensive, but may also result in insufficient light to maintain operation due to excessive initial deviation. Therefore, in this application, when switching from the third operating mode to the first or second operating mode, the energy management controller 40 controls the drive mechanism 50 to perform a coarse positioning operation before entering the corresponding target operating mode. This allows for a faster recovery of the high-efficiency power generation state, improved energy recovery efficiency, and reduced ineffective energy consumption caused by blind fine-tuning. This further enhances the response speed and self-recovery capability of the drive system under intermittent operating conditions.

[0053] Due to the weak ambient light and high diffuse component under complex weather conditions such as early morning, dusk, or cloudy days, the signal-to-noise ratio of the photosensitive signal is extremely low, making it difficult to form a clear directional gradient. This causes the drive system to be unable to determine the rotation direction, and may even search towards the backlight side, requiring repeated start-stop of the drive mechanism 50 to adjust its position. This consumes a large amount of the already limited electrical energy in the hybrid energy storage unit 30. Therefore, in this application, the coarse positioning operation includes: estimating the current solar azimuth angle based on the real-time clock signal and pre-stored geographical location information using a solar position algorithm, i.e., the energy management controller 40 calculates the current solar azimuth angle based on the built-in real-time clock. The system provides the current year, month, day, hour, minute, and second, and combines this with the longitude λ and latitude φ of the installation location pre-stored in non-volatile memory. It then converts the local time to Coordinated Universal Time (UTC) based on the system's configured time zone offset. Subsequently, it calls a pre-configured solar position calculation module and uses a simplified solar azimuth algorithm known in the art (e.g., based on the Michalsky model or NOAA's publicly available solar position calculation formula) to calculate the Julian day, mean anomaly, true anomaly, ecliptic longitude, declination, and hour angle sequentially. Finally, it solves for the solar azimuth angle az using the following formula:

[0054]

[0055]

[0056] Where H is the hour angle, δ is the solar declination, Φ is the local latitude, θ is the zenith angle, and the azimuth angle az is 0° for due south, negative for east, and positive for west (unit: degrees). The controller converts the calculated solar azimuth angle into the mechanical rotation angle corresponding to the drive mechanism 50, and controls the drive mechanism 50 to rotate the photovoltaic panel 10 to within a predetermined deviation range (e.g., ±5°) of that angle in one operation. This coarse positioning process is completely independent of ambient light signals, and can bring the photovoltaic panel 10 into the effective starting range for subsequent high-precision or medium-precision tracking in a single action, significantly reducing the energy consumption during the system wake-up phase, and ensuring reliable reconstruction of solar tracking capability even under extreme conditions such as no light, weak light, or sensor failure.

[0057] In the first or second operating mode, the drive mechanism 50 needs to be frequently started and stopped or undergo angle fine-tuning, resulting in high instantaneous power demand. In this mode, the energy management controller 40 prioritizes power supply from the capacitor 31, utilizing its high power density and rapid discharge characteristics to efficiently meet the peak current required for the drive mechanism 50's startup and dynamic adjustment. This minimizes the risk of accelerated aging or voltage drop in the battery 32 due to high-current pulse discharge. In the third operating mode, the drive mechanism 50 is in standby mode, with lower operating frequency and lower power demand, but potentially longer duration. Its high energy density characteristics can be fully utilized to provide stable energy output, resolving the inherent contradiction between power response speed and energy density in a single energy storage element. Regardless of whether the capacitor 31 or the battery 32 supplies power to the drive mechanism 50, energy conversion is required through the DC-DC converter 33 to ensure it meets the power standards required by the drive mechanism 50.

[0058] Because capacitor 31 is rapidly depleted due to high-power discharge during frequent driving, it lacks the ability to continuously replenish energy. If it relies solely on direct charging from photovoltaic panel 10 or thermoelectric conversion module 20, its terminal voltage may fail to rise back to the driving threshold for an extended period when there is insufficient sunlight, a small temperature difference, or the system is in a low-power state, leading to the loss of tracking function. Therefore, in this application, the energy management controller 40 replenishes capacitor 31 through battery 32, utilizing the stable energy stored in battery 32 to actively maintain the usable voltage of capacitor 31 during periods of intermittent sunlight, at night, or under low-light conditions. The system ensures that the battery 31 is always ready to respond to the next high-power drive command. Meanwhile, the power replenishment process is intelligently triggered by the energy management controller 40 based on the voltage of the capacitor 31 and the charge status of the battery 32. It is only executed when the voltage of the capacitor 31 is lower than a set threshold and the battery 32 is fully charged. This avoids unnecessary energy conversion losses as much as possible and prevents the battery 32 from being over-discharged. As a result, a synergistic relationship is formed between the capacitor 31 and the battery 32, with the battery 32 providing energy storage and the capacitor 31 releasing energy instantaneously. This enables the hybrid energy storage unit 30 to achieve efficient division of labor between dynamic load and static storage.

[0059] In addition to the preferred embodiments described above, the present invention has other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection claimed by the present invention.

Claims

1. A photothermal coupling self-powered tracking drive system, characterized in that, The device includes a photovoltaic panel, a thermoelectric conversion module, a hybrid energy storage unit, an energy management controller, and a drive mechanism. The thermoelectric conversion module is located on the back side of the photovoltaic panel and generates electricity by utilizing the temperature difference between the waste heat generated by the photovoltaic panel under sunlight and the environment. The photovoltaic panel and the thermoelectric conversion module are electrically connected to the hybrid energy storage unit, which includes a capacitor and a rechargeable battery connected in parallel. The energy management controller is electrically connected to the photovoltaic panel, the thermoelectric conversion module, and the hybrid energy storage unit, and is used to collect ambient light intensity, the state of charge of the battery, and the terminal voltage of the capacitor, and generate control commands based on the collected signals. The drive mechanism is connected to the energy management controller and, in response to the control commands, drives the photovoltaic panel to adjust its azimuth and / or elevation angles for solar tracking.

2. The photothermal coupling self-powered tracking drive system according to claim 1, characterized in that, The operating modes of the drive mechanism include a first operating mode: when the ambient light intensity is greater than a first threshold and the battery charge level is higher than a second threshold, the drive mechanism performs solar tracking motion with a first angular resolution. Second operating mode: When the ambient light intensity is between the third threshold and the first threshold, and the battery charge level is between the fourth threshold and the second threshold, the drive mechanism performs solar tracking motion with a second angular resolution. The third operating mode is activated when the ambient light intensity is less than the fifth threshold or the battery charge level is lower than the sixth threshold, and the drive mechanism stops the solar tracking movement. Wherein, the second angular resolution is lower than the first angular resolution, the first threshold is greater than the third threshold, the second threshold is greater than the fourth threshold, the third threshold is greater than the fifth threshold, and the fourth threshold is greater than the sixth threshold.

3. The photothermal coupling self-powered tracking drive system according to claim 2, characterized in that, The first angular resolution is ±0.1°, and the second angular resolution is ±1°.

4. The photothermal coupling self-powered tracking drive system according to claim 2, characterized in that, When switching from the third operating mode to the first or second operating mode, the energy management controller controls the drive mechanism to perform a coarse positioning operation first, and then enter the corresponding target operating mode.

5. The photothermal coupling self-powered tracking drive system according to claim 4, characterized in that, The coarse positioning operation includes: estimating the current solar azimuth angle based on real-time clock signals and pre-stored geographical location information using a solar position algorithm, and controlling the drive mechanism to rotate the photovoltaic panel to a predetermined angle deviation range of the solar azimuth angle.

6. The photothermal coupling self-powered tracking drive system according to claim 2, characterized in that, In the first or second operating mode, the energy management controller prioritizes using the capacitor to supply power to the drive mechanism. In the third operating mode, the energy management controller controls the battery to supply power to the drive mechanism.

7. The photothermal coupling self-powered tracking drive system according to claim 2, characterized in that, The energy management controller replenishes the capacitor via the battery.

8. The photothermal coupling self-powered tracking drive system according to claim 1, characterized in that, The energy management controller controls the storage of steady-state electrical energy output from the photovoltaic panel or the thermoelectric conversion module into the battery, and the energy management controller controls the storage of transient electrical energy output from the photovoltaic panel or the thermoelectric conversion module into the capacitor.

9. The photothermal coupling self-powered tracking drive system according to claim 1, characterized in that, A heat-conducting layer is provided between the thermoelectric conversion module and the back plate of the photovoltaic panel.

10. The photothermal coupling self-powered tracking drive system according to claim 1, characterized in that, The thermoelectric conversion module has multiple heat dissipation fins spaced apart on the side away from the photovoltaic panel.

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