Photovoltaic power supply device, photovoltaic shelter power supply system and control method

Abstract

The invention provides a photovoltaic power supply device, a photovoltaic shelter power supply system and a control method, and belongs to the technical field of new energy photovoltaic power generation, the device comprises a lithium battery, a photovoltaic module and a main controller, the lithium battery is electrically connected with the photovoltaic module, and the photovoltaic module is electrically connected with a load; the photovoltaic module is used for converting light energy into alternating-current electric energy to supply power to an external load; the main controller is in communication connection with the photovoltaic module, the lithium battery and the load and is used for obtaining the electrical load of the external load, the power of the maximum alternating-current electric energy obtained by converting all light energy through the photovoltaic module and the SOC of the lithium battery, judging whether the SOC of the lithium battery is larger than a preset electric quantity threshold value or not when the electrical load is larger than the power of the maximum alternating-current electric energy, and if yes, outputting the lithium battery. If yes, the lithium battery is controlled to discharge, and if not, the lithium battery is controlled to stop discharging. The output strategy of the photovoltaic power supply device can be controlled according to the characteristics of the lithium battery and the photovoltaic power supply, so that the photovoltaic power supply device is always kept in an optimal state.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy photovoltaic power generation, and specifically relates to a photovoltaic power supply device, a photovoltaic cabin power supply system and a control method thereof. Background Art

[0002] Photovoltaic energy is one of the important directions of green energy and has been widely applied in China. Due to different power generation powers, the photovoltaic power supply systems and power generation application scenarios are also different.

[0003] The existing photovoltaic energy systems are mainly divided into high-power, medium-power, low-power, and micro-power. For example, the photovoltaic systems in deserts, lake beaches, and hilly areas are all high-power above one hundred kilowatts, and these electric energies are directly connected to the power grid; the photovoltaic systems in factories and urban intelligent buildings are all medium-power of dozens of kilowatts, and these electric energies are used for internal energy-saving applications and mainly for internal consumption; the outdoor nomadic civilian mobile photovoltaic systems or mobile photovoltaic power stations are all low-power in the range of one kilowatt to ten kilowatts and are used for living and entertainment electricity; the outdoor photovoltaic street lights or individual soldier photovoltaic power supplies are micro-power from a few watts to a few hundred watts.

[0004] The reliability of a photovoltaic power generation system involves the stability and lifespan of solar cells and the reliability of components such as inverters. In harsh environments, problems such as aging and thermal runaway of battery components will affect the system reliability. However, the prior art often ignores the characteristics of lithium battery modules and photovoltaic power supplies, resulting in the entire photovoltaic power supply system not reaching the optimal working state. Summary of the Invention

[0005] In view of this, it is necessary to provide a photovoltaic power supply device, a photovoltaic cabin power supply system and a control method thereof to control the output strategy of the photovoltaic power supply device according to the characteristics of lithium batteries and photovoltaic power supplies, so that it always maintains the optimal state.

[0006] To solve the above technical problems, in a first aspect, the present invention provides a photovoltaic power supply device, including a lithium battery, a photovoltaic module and a main controller. The lithium battery and the photovoltaic module are electrically connected, and the photovoltaic module is electrically connected to a load. The photovoltaic module is used to convert light energy into alternating current electric energy to supply power to an external load. The main controller is communicatively connected to the photovoltaic module, the lithium battery and the load, and is used to obtain the power consumption load of the external load, the power of the maximum alternating current electric energy obtained by converting all the light energy of the photovoltaic module, and the SOC of the lithium battery. When the power consumption load is greater than the power of the maximum alternating current electric energy, it is determined whether the SOC of the lithium battery is greater than a preset power threshold. If so, the lithium battery is controlled to discharge; if not, the lithium battery is controlled to stop discharging.

[0007] In some embodiments of the present invention, the photovoltaic module is further used to convert light energy into direct current electric energy and output it to charge the lithium battery. The main controller is also used to control the charging of the lithium battery when the electrical load is less than the power of the maximum AC electric energy.

[0008] In some embodiments of the present invention, the main controller is further used to obtain the temperature of the lithium battery, and adjust the discharge current or charging current of the lithium battery according to a preset relationship table of the charge-discharge current of the lithium battery, the SOC of the lithium battery, and the temperature of the lithium battery.

[0009] In some embodiments of the present invention, the photovoltaic module includes: a grid connection interface for accessing the power grid; When the photovoltaic module is connected to the power grid, the main controller is further used to control the photovoltaic module to receive the AC electric energy input from the power grid when the electrical load is greater than the power of the maximum AC electric energy, or, when the electrical load is less than the power of the maximum AC electric energy and the SOC of the lithium battery is 100%, control the photovoltaic module to output the redundant AC electric energy after powering the external load to the power grid.

[0010] In some embodiments of the present invention, the photovoltaic power supply device further includes: a temperature control module and a moisture removal module. The temperature control module is electrically connected to the photovoltaic module through a first switch and is used to control the temperature within a preset space range. The moisture removal module is electrically connected to the photovoltaic module through a second switch and is used to reduce the humidity within a preset space range; When the temperature is higher than the upper limit of the preset temperature range, the humidity is greater than the preset humidity threshold, and the SOC of the lithium battery is greater than the preset power threshold, the main controller turns on the first switch to start the temperature control module for cooling, and at the same time turns on the second switch to start the moisture removal module for moisture removal until the temperature drops back to the preset temperature range and the humidity is less than the preset humidity threshold; When the temperature is lower than the lower limit of the preset temperature range, the humidity is not greater than the preset humidity threshold, and the SOC of the lithium battery is greater than the preset power threshold, the main controller turns on the first switch to start the temperature control module for heating until the temperature rises back to the preset temperature range and then turns off the first switch; When the temperature is lower than the lower limit of the preset temperature range, the humidity is greater than the preset humidity threshold, and the SOC of the lithium battery is greater than the preset power threshold, the main controller turns on the first switch to start the temperature control module for heating, and at the same time turns on the second switch to start the moisture removal module for moisture removal until the temperature rises back to the preset temperature range and the humidity is less than the preset humidity threshold, and then turns off the first switch and the second switch.

[0011] In some embodiments of the present invention, the photovoltaic power supply device further includes: Touch screen, communicatively connected to the main controller, for data exchange with the main controller, receiving and displaying the maximum AC power, electrical load, lithium battery SOC, temperature, and humidity obtained by the main controller, and also for user interaction and sending the interaction result to the main controller, so that the main controller controls the photovoltaic inverter and / or temperature control module and / or dehumidification module to perform corresponding actions; Among them, the user interaction at least includes: Selecting whether to receive the second electric energy input from the power grid; Selecting to output the remaining part after supplying the AC power externally to the power grid or restricting the power of the maximum AC power converted by the photovoltaic module; Selecting whether to turn on the temperature control module; Selecting whether to turn on the dehumidification module; Switching power supply, with the input end electrically connected to the photovoltaic module and the output end electrically connected to the touch screen and the main controller, for supplying power to the touch screen and the main controller.

[0012] In some embodiments of the present invention, the photovoltaic module includes: Photovoltaic array, for converting light energy into first electric energy; Photovoltaic inverter, electrically connected to the photovoltaic array and communicatively connected to the main controller, for converting the first electric energy into the DC electric energy and / or AC electric energy.

[0013] In some embodiments of the present invention, the photovoltaic array is composed of several photovoltaic panels, and the photovoltaic panels are physically fixed by hinges; The photovoltaic panel includes: a solar panel, a square structural member, a telescopic support mechanism, a first ground fixing plate, and a second ground fixing plate; The square structural member is fixedly connected to the edge of the solar panel, and the square structural member is fixed to the ground through the first ground fixing plate. Among them, the frame in the square structural member in contact with the ground is connected to the first ground fixing plate by a hinge; One end of the telescopic support mechanism is fixedly connected to the second ground fixing plate and fixed to the ground through the second ground fixing plate, and the other end is connected to the frame of the square structural member away from the ground by a hinge, and there are different gear lengths of telescopic fixation between the two ends.

[0014] In a second aspect, the present invention further provides a photovoltaic cabin power supply system, including: The photovoltaic power supply device according to any one of the above device items; Cabin, for accommodating the photovoltaic power supply device.

[0015] Thirdly, the present invention also provides a control method for a photovoltaic power supply device, which is applied to the photovoltaic power supply device described in any one of the above device items, and includes: Obtain the power consumption of an external load, the power of the maximum alternating current energy obtained by converting all the light energy of the photovoltaic module, and the SOC of the lithium battery. When the power consumption of the external load is greater than the power of the maximum alternating current energy, determine whether the SOC of the lithium battery is greater than a preset power threshold. If so, control the lithium battery to discharge; if not, control the lithium battery to stop discharging.

[0016] The beneficial effects of the present invention are as follows: The present invention provides a photovoltaic power supply device. The main controller obtains the output power of the current photovoltaic module and the power consumption of the external load. When there is an imbalance in power supply between the photovoltaic module and the external load, the SOC of the lithium battery module is further considered. When the lithium battery has sufficient power, the photovoltaic module and the lithium battery module are controlled to supply power simultaneously, so that the output of the power supply device meets the power consumption demand and reaches the optimal state in terms of output. In addition, when the power is insufficient, the main controller will stop the external power supply of the lithium battery module and switch to the photovoltaic module to supply power alone, avoiding potential safety hazards and affecting the service life caused by forced battery power supply, and keeping the overall power supply device in the optimal state in terms of hardware maintenance. Therefore, according to the characteristics of the lithium battery and the photovoltaic power supply, the output strategy of the photovoltaic power supply device is controlled to keep it in the optimal state at all times. Description of the Drawings In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a schematic structural diagram of an embodiment of the photovoltaic power supply device provided by the present invention; Figure 2 It is a schematic structural diagram of an embodiment of the photovoltaic power supply device provided by the present invention, including a temperature control module, a moisture exhaust module, a touch screen, and a switching power supply; Figure 3 It is a schematic structural diagram of an embodiment of the photovoltaic module provided by the present invention; Figure 4 It is a schematic structural diagram of an embodiment of the photovoltaic cabin power supply system provided by the present invention; Figure 5 It is a schematic flowchart of an embodiment of the control method for the photovoltaic power supply device provided by the present invention. Detailed Embodiments

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0019] In the description of the embodiments of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0020] The descriptions such as "first" and "second" involved in the embodiments of the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Therefore, the technical features defined with "first" and "second" may explicitly or implicitly include at least one such feature.

[0021] Referring to "embodiments" herein means that the specific features, structures, or characteristics described in connection with the embodiments may be included in at least one embodiment of the present invention. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

[0022] The present invention provides a photovoltaic power supply device, a photovoltaic cabin power supply system, and a control method, which will be described separately below.

[0023] Figure 1 FIG. is a schematic structural diagram of an embodiment of the photovoltaic power supply device 10 provided by the present invention, which is specifically applied to a photovoltaic cabin power supply system. As Figure 1 shown, the photovoltaic power supply device 10 includes: In a first aspect, the present invention provides a photovoltaic power supply device 10, including: a lithium battery 110, a photovoltaic module 120, and a main controller 130. The lithium battery 110 and the photovoltaic module 120 are electrically connected, and the photovoltaic module 120 is electrically connected to a load; The photovoltaic module 120 is configured to convert light energy into alternating current electrical energy to supply power to an external load; The main controller 130 is communicatively connected to the photovoltaic module 120, the lithium battery 110, and the load, and is configured to obtain the power consumption load of the load, the power of the maximum AC electric energy obtained by converting all the light energy of the photovoltaic module 120, and the lithium battery SOC. When the power consumption load is greater than the power of the maximum AC electric energy, it determines whether the lithium battery SOC is greater than a preset power threshold. If so, it controls the lithium battery 110 to discharge; if not, it controls the lithium battery 110 to stop discharging.

[0024] In some embodiments of the present invention, to improve the utilization efficiency of the photovoltaic module, the photovoltaic module 120 is further configured to convert light energy into DC electric energy and output it to charge the lithium battery 110.

[0025] Meanwhile, to ensure that the overall output of the power supply device 10 can meet the external load requirements, the main controller 130 is further configured to control the lithium battery 110 to charge when the power consumption load is less than the power of the maximum AC electric energy.

[0026] To further maintain the optimal state of the photovoltaic power supply device 10, in terms of hardware, the present invention also takes into account the aging of the battery components and the impact of thermal runaway on the battery service life. Therefore, in some embodiments of the present invention, the main controller 130 is further configured to obtain the temperature of the lithium battery 110 and adjust the discharge current or charge current of the lithium battery 110 according to a preset relationship table of the lithium battery charge and discharge current with the lithium battery SOC and the lithium battery temperature. The specific content is shown in Table 1 below.

[0027] Table 1 Relationship between lithium battery charge and discharge limits, temperature, and SOC limits (C is the standard charge and discharge rate)

[0028] It should be noted that since the aging of the battery components and thermal runaway are related to improper battery use, the present invention adjusts the charge and discharge current of the lithium battery considering the SOC and temperature of the lithium battery, restricts the use of the lithium battery, avoids the lithium battery from operating under a power-fed condition, reasonably uses the lithium battery, and avoids problems such as battery aging and thermal runaway, thereby avoiding the impact of the above problems on the system reliability.

[0029] In some embodiments of the present invention, the photovoltaic module 120 includes: a grid connection interface for connecting to the power grid; When the photovoltaic module is connected to the power grid, the main controller 130 is further configured to control the photovoltaic module 120 to receive the AC electric energy input from the power grid when the power consumption load is greater than the power of the maximum AC electric energy, or to control the photovoltaic module to output the redundant AC electric energy after supplying power to the external load to the power grid when the power consumption load is less than the power of the maximum AC electric energy and the lithium battery SOC is 100%.

[0030] It should be noted that when the electrical load is greater than the total electrical energy power output by the entire photovoltaic power supply device 10 and the photovoltaic power supply device 10 is connected to the power grid, the main controller 130 preferentially controls the photovoltaic power supply device 10 to convert light energy for power supply, and the insufficient part of the energy supply is supplemented by the power grid; when the total electrical energy of the photovoltaic power supply device 10 meets the electrical load, the main controller 130 decides whether to feed back the redundant electrical energy to the power grid according to the battery level of the lithium battery 110 to prevent potential safety hazards caused by overcharging of the lithium battery 110.

[0031] For example Figure 2 , while considering the influence of the characteristics of the lithium battery on the working state of the photovoltaic power supply device 10, the present invention also takes into account the influence of the working environment on its working state. In some embodiments of the present invention, the photovoltaic power supply device 10 further includes: a temperature control module 140 and a dehumidification module 150. The temperature control module 140 is electrically connected to the photovoltaic module 120 through a first switch 141 and is used to control the temperature within a preset space range. The dehumidification module 150 is electrically connected to the photovoltaic module 120 through a second switch 151 and is used to reduce the humidity within a preset space range; When the temperature is higher than the upper limit of the preset temperature range, the humidity is greater than the preset humidity threshold, and the lithium battery SOC is greater than the preset battery level threshold, the main controller 130 turns on the first switch 141 to start the temperature control module for cooling, and at the same time turns on the second switch 151 to start the dehumidification module for dehumidification until the temperature drops back within the preset temperature range and the humidity is less than the preset humidity threshold; When the temperature is lower than the lower limit of the preset temperature range, the humidity is not greater than the preset humidity threshold, and the lithium battery SOC is greater than the preset battery level threshold, the main controller 130 turns on the first switch 141 to start the temperature control module 140 for heating until the temperature rises back within the preset temperature range and then turns off the first switch 141; When the temperature is lower than the lower limit of the preset temperature range, the humidity is greater than the preset humidity threshold, and the lithium battery SOC is greater than the preset battery level threshold, the main controller 130 turns on the first switch 141 to start the temperature control module 140 for heating, and at the same time turns on the second switch 151 to start the dehumidification module 150 for dehumidification until the temperature rises back within the preset temperature range and the humidity is less than the preset humidity threshold, and then turns off the first switch 141 and the second switch 151.

[0032] It can be understood that when the photovoltaic power supply device 10 works in a low-temperature environment, the temperature control module is started for heating, so as to accelerate the time from startup to entering the normal operation state; when the photovoltaic power supply device 10 works in a high-temperature environment, the temperature control module is started for heat dissipation to avoid system collapse caused by overheating; when the device to be controlled works in a high-humidity environment, the dehumidification module is started for ventilation and dehumidification to avoid damage to the device due to moisture. Thus, it is ensured that the photovoltaic power supply device operates in the best environment.

[0033] In addition, to enhance the practicability of the photovoltaic power supply device 10, while enabling it to achieve automatic adjustment through the main controller 130, it also enables testers to intuitively observe the operating data of the device and manually adjust the device according to the operating data. For example Figure 2 , in some embodiments of the present invention, the photovoltaic power supply device 10 further includes: A touch screen 160, communicatively connected to the main controller 130, for exchanging data with the main controller 130, receiving and displaying the maximum AC power, power consumption load, lithium battery SOC, temperature, and humidity obtained by the main controller 130, and also for user interaction and sending the interaction result to the main controller 130, so that the main controller 130 controls the photovoltaic module 120 and / or the temperature control module 140 and / or the dehumidification module 150 to perform corresponding actions; Among them, user interaction at least includes: Selecting whether to receive the second electric energy input from the power grid; Selecting to output the remaining part after supplying AC power externally to the power grid or restricting the AC power output of the photovoltaic module; Selecting whether to turn on the temperature control module; Selecting whether to turn on the dehumidification module; A switching power supply 170, with its input end electrically connected to the photovoltaic module 120 and its output end electrically connected to the touch screen 160 and the main controller 130, for supplying power to the touch screen 160 and the main controller 130.

[0034] Finally, in some embodiments of the present invention, the photovoltaic module 120 includes: A photovoltaic array 121, for converting light energy into AC electric energy; A photovoltaic inverter 122, electrically connected to the photovoltaic array and communicatively connected to the main controller, for converting the maximum AC electric energy into DC electric energy and / or AC electric energy.

[0035] For example Figure 3 , in a specific embodiment, the photovoltaic inverter 122 has at least 2 or more photovoltaic input interfaces (PV1, PV2), 1 lithium battery interface (BAT), 1 grid connection interface (OI), 1 off-grid interface (GOI), and 1 CAN communication interface (CAN). Among them, the photovoltaic input interfaces PV1 and PV2 are used to receive the electric energy input by the photovoltaic array 121, the lithium battery interface BAT is used to output DC electric energy to the lithium battery 110 or receive the DC electric energy input by the lithium battery 110, the off-grid interface OGI is used to output AC electric energy to external electrical equipment, and the CAN communication interface is used for data exchange with the main controller 130. In this way, when any one or more of the photovoltaic electric energy and the lithium battery electric energy are input, the off-grid interface has AC electric energy output, and it is not affected by whether external control power supply is provided, effectively improving the reliability of the photovoltaic power supply device 10.

[0036] Further, considering the stability of the present invention in outdoor scenarios, in some embodiments of the present invention, the photovoltaic array 121 is composed of a plurality of photovoltaic panels, and the photovoltaic panels are physically fixed by hinges. The photovoltaic panel includes: a solar panel, a square structural member, a telescopic support mechanism, a first ground fixing plate, and a second ground fixing plate. The square structural member is fixedly connected to the edge of the solar panel, and the square structural member is fixed to the ground through the first ground fixing plate. Among them, the frame of the square structural member in contact with the ground is connected to the first ground fixing plate by a hinge. One end of the telescopic support mechanism is fixedly connected to the second ground fixing plate and fixed to the ground through the second ground fixing plate. The other end is connected to the frame of the square structural member away from the ground by a hinge, and the telescopic fixed length between the two ends is divided into different gears.

[0037] It should be noted that in the present invention, the square structural member is fixedly connected to the frame of the solar panel and fixed to the ground through the first ground fixing plate to ensure that the solar panel remains fixed in its original position in strong wind weather. In addition, a telescopic support structure is provided between the second ground fixing plate and the square structural member. In the case of changes in the lighting environment, the angle between the solar panel and the ground can also be adjusted by adjusting the length of the support structure, so that the solar panel always maintains the maximum light receiving area, thereby improving the operation reliability of the photovoltaic power supply device in outdoor scenarios.

[0038] In summary, the beneficial effects of the photovoltaic power supply device provided by the present invention include: (1) Design the control strategy of the photovoltaic power system according to the state of the lithium battery, and always keep the operation of the device in the optimal state.

[0039] (2) The photovoltaic module can be quickly deployed and retracted, the angle between the photovoltaic module and the ground can be adjusted according to the direction of sunlight, and it can also be determined whether to fix the photovoltaic panel module to the ground according to the outdoor wind speed, ensuring that the photovoltaic power supply device can continue to operate stably in harsh environments.

[0040] (3) Through the temperature control module, when the real-time temperatures of the photovoltaic module and the lithium battery are lower than the low temperature threshold, the photovoltaic module can supply electrical energy to the temperature control module to heat the photovoltaic module and the lithium battery through the temperature control module, realizing the low-temperature self-start of the photovoltaic power supply device. It does not need to rely on an external heat source, which is convenient for field use, improves the applicability of the photovoltaic power supply system, and the photovoltaic power supply device can be heated as long as there is sunlight, enabling the photovoltaic power supply device to start in any low-temperature environment and improving the electrical energy efficiency of the photovoltaic power supply system. In a high-temperature environment, the temperature control module can also dissipate heat from the photovoltaic module and the lithium battery, thereby ensuring the efficient and reliable operation of the photovoltaic power supply device in a wide temperature range. Further, the temperature control module, the photovoltaic module, and the lithium battery are all independent modules, that is, temperature control and power generation are independent of each other and do not affect each other, improving the safety and reliability of the photovoltaic power supply device.

[0041] (4) Associate the internal temperature and humidity control conditions of the power supply device with the lithium battery SOC to avoid the lithium battery running out of power due to unconditional operation and the difficulty of system maintenance.

[0042] Such as Figure 4 , on the second aspect, the present invention also provides a photovoltaic cabin power supply system 40, including: The photovoltaic power supply device 10 described in any one of the above device items; A cabin 410 for housing the photovoltaic power supply device 10.

[0043] Such as Figure 5 , on the third aspect, the present invention also provides a control method for a photovoltaic power supply device, which is applied to the photovoltaic power supply device described in any one of the above device items, including: Step S501, obtain the power consumption load of the external load, the power of the maximum AC electrical energy obtained by converting all the light energy of the photovoltaic module, and the lithium battery SOC; Step S502, when the power consumption load is greater than the power of the maximum AC electrical energy, determine whether the lithium battery SOC is greater than the preset power threshold. If so, enter step S503, otherwise enter step S504; Step S503, control the lithium battery to discharge; Step S504, control the lithium battery to stop discharging.

[0044] It should be noted that Figure 5 The method shown in is stored in the main controller 130 in the form of a software program, that is, the main body implementing this method is the main controller 130.

[0045] The above has introduced in detail a photovoltaic power supply device, a photovoltaic cabin power supply system and a control method provided by the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A photovoltaic power supply device, characterized in that: It includes a lithium battery, a photovoltaic module and a main controller, wherein the lithium battery and the photovoltaic module are electrically connected, and the photovoltaic module is electrically connected to a load; The photovoltaic module is used to convert light energy into AC power to supply power to an external load; The main controller is communicatively connected with the photovoltaic module, the lithium battery and the load, and is used to obtain the power load of the external load, the power of the maximum AC power obtained by the photovoltaic module converting all light energy, and the SOC of the lithium battery. When the power load is greater than the power of the maximum AC power, it is determined whether the SOC of the lithium battery is greater than a preset power threshold. If so, the lithium battery is controlled to discharge, and if not, the lithium battery is controlled to stop discharging.

2. The photovoltaic power supply device according to claim 1, characterized in that: The photovoltaic module is also used to convert light energy into direct current electricity and output it to charge the lithium battery; The main controller is also used to control the charging of the lithium battery when the power load is less than the power of the maximum AC power.

3. The photovoltaic power supply device according to claim 2, characterized in that: The main controller is also used to obtain the temperature of the lithium battery, and adjust the discharge current or charge current of the lithium battery according to a preset relationship table of the lithium battery charge and discharge current, the lithium battery SOC and the lithium battery temperature.

4. The photovoltaic power supply device according to claim 1, characterized in that: The photovoltaic module comprises: a grid-connected interface for connecting to a power grid; When the photovoltaic module is connected to the power grid, the main controller is also used to control the photovoltaic module to receive the AC power input from the power grid when the power load is greater than the power of the maximum AC power, or, when the power load is less than the power of the maximum AC power and the lithium battery SOC is 100%, control the photovoltaic module to output the redundant AC power after supplying power to the external load to the power grid.

5. The photovoltaic power supply device according to claim 1, characterized in that: The photovoltaic power supply device also includes: A temperature control module and a dehumidification module, wherein the temperature control module is electrically connected to the photovoltaic module through a first switch to control the temperature within a preset space range, and the dehumidification module is electrically connected to the photovoltaic module through a second switch to reduce the humidity within the preset space range; When the temperature is higher than the upper limit of the preset temperature range, the humidity is greater than the preset humidity threshold, and the SOC of the lithium battery is greater than the preset power threshold, the main controller turns on the first switch to start the temperature control module to cool down, and turns on the second switch to start the dehumidification module to dehumidify, until the temperature drops back to the preset temperature range and the humidity is less than the preset humidity threshold; The main controller turns on the first switch to start the temperature control module for heating when the temperature is lower than the lower limit of the preset temperature range, the humidity is not greater than the preset humidity threshold, and the SOC of the lithium battery is greater than the preset power threshold, and then turns off the first switch after the temperature rises back to within the preset temperature range; When the temperature is lower than the lower limit of the preset temperature range, the humidity is greater than the preset humidity threshold and the lithium battery SOC is greater than the preset power threshold, the main controller turns on the first switch to start the temperature control module for heating, and turns on the second switch to start the dehumidification module for dehumidification, and then disconnects the first switch and the second switch until the temperature rises back to the preset temperature range and the humidity is lower than the preset humidity threshold.

6. The photovoltaic power supply device according to claim 4 or 5, characterized in that: The photovoltaic power supply device also includes: A touch screen is connected to the main controller for data exchange with the main controller, receives and displays the maximum AC power, power load, lithium battery SOC, temperature and humidity acquired by the main controller, and is also used for user interaction and sends the interaction result to the main controller, so that the main controller controls the photovoltaic inverter and / or the temperature control module and / or the dehumidification module to perform corresponding actions; Wherein, the user interaction at least includes: Select whether to receive the second electric energy input from the power grid; Selecting to output the remaining part of the AC power after supplying power to the outside to the power grid or limiting the power of the photovoltaic module to convert the maximum AC power; Choose whether to turn on the temperature control module; Choose whether to turn on the dehumidification module; A switching power supply, the input end of which is electrically connected to the photovoltaic module, and the output end of which is electrically connected to the touch screen and the main controller, is used to supply power to the touch screen and the main controller.

7. The photovoltaic power supply device according to claim 1, characterized in that: The photovoltaic module comprises: A photovoltaic array, for converting light energy into first electrical energy; The photovoltaic inverter is electrically connected to the photovoltaic array and is in communication with the main controller, and is used for converting the first electric energy into the direct current electric energy and / or alternating current electric energy.

8. The photovoltaic power supply device according to claim 7, characterized in that: The photovoltaic array is composed of a plurality of photovoltaic panels, and the photovoltaic panels are physically fixed by being connected by hinges; The photovoltaic panel comprises: a solar cell panel, a square structural member, a retractable support mechanism, a first ground fixing plate and a second ground fixing plate; The square structure is fixedly connected to the edge of the solar cell panel, and the square structure is fixed to the ground via a first ground fixing plate, wherein the frame of the square structure in contact with the ground is connected to the first ground fixing plate by a hinge; One end of the retractable support mechanism is fixedly connected to the second ground fixing plate and fixed to the ground through the second ground fixing plate, and the other end is connected to the frame of the square structure away from the ground through a hinge, and the two ends are divided into retractable fixed lengths of different gears.

9. A photovoltaic shelter power supply system, characterized in that: include: A photovoltaic power supply device as claimed in any one of claims 1 to 8; A cabin is used to store the photovoltaic power supply device.

10. A photovoltaic power supply device control method, characterized in that: A photovoltaic power supply device as claimed in any one of claims 1 to 8, comprising: Obtain the power load of the external load, the maximum AC power obtained by the photovoltaic module converting all light energy, and the lithium battery SOC; When the power load is greater than the power of the maximum AC power, it is determined whether the SOC of the lithium battery is greater than a preset power threshold. If so, the lithium battery is controlled to discharge; if not, the lithium battery is controlled to stop discharging.

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