Household photovoltaic system and thermal management control method thereof

Abstract

The invention provides a household photovoltaic system and a heat management control method thereof, and the system comprises a photovoltaic panel layer, a battery layer, a controller inversion layer, a heat pump layer, and a heat pump assembly. The photovoltaic panel layer, the battery layer and the controller inversion layer are separated through a first heat exchanger interlayer, a second heat exchanger interlayer and a third heat exchanger interlayer in the heat pump assembly, and the first heat exchanger interlayer, the second heat exchanger interlayer and the third heat exchanger interlayer are used for conducting temperature regulation and control on the photovoltaic panel layer, the battery layer and the controller inversion layer. By applying the household photovoltaic system, the temperature regulation and control requirements of each layer can be met, the influence of too high temperature and too low temperature on the power generation efficiency of the photovoltaic panel is reduced, and the temperature rise reliability of the inverter system and the battery is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic systems, and in particular to a household photovoltaic system and a thermal management control method for the household photovoltaic system. Background Art

[0002] In the existing photovoltaic system, the high temperature of the photovoltaic panels in the summer will reduce the power generation efficiency. In the winter, the low temperature will also affect the power generation efficiency. At the same time, the performance and service life of the energy storage battery and the inverter system are also closely related to the temperature. The energy storage battery and the inverter system need to meet certain operating temperature requirements. Too high or too low temperature will cause the energy storage battery to not work normally.

[0003] One existing method is that the photovoltaic system places the energy storage battery cabinet outdoors and connects it to the indoor heat pump heating and cooling system. There is no need to set up a separate air conditioner for the energy storage system. The heat pump heating and cooling system can actively solve the temperature control problem of the energy storage battery cabinet and enhance the safety of the energy storage battery.

[0004] However, this solution does not take into account the temperature requirements of photovoltaic panels and inverter systems. At the same time, photovoltaic panels, energy storage batteries and inverter systems have different temperature requirements. How to thermally manage the core components of the photovoltaic system is also a direction that needs to be studied.

[0005] Therefore, a more optimized photovoltaic system needs to be considered. Summary of the invention

[0006] The first object of the present invention is to provide a household photovoltaic system which can reduce the influence of high and low temperatures on the power generation efficiency of photovoltaic panels and ensure the temperature rise reliability of inverter systems and batteries.

[0007] The second object of the present invention is to provide a thermal management control method for a household photovoltaic system that can reduce the impact of high and low temperatures on the power generation efficiency of photovoltaic panels and ensure the temperature rise reliability of the inverter system and the battery.

[0008] In order to achieve the above-mentioned first purpose, the household photovoltaic system provided by the present invention includes a photovoltaic panel layer, a battery layer, a controller inverter layer, a heat pump layer and a heat pump assembly, and the photovoltaic panel layer, the battery layer, the controller inverter layer and the heat pump layer are arranged in sequence from top to bottom in the vertical direction; the heat pump assembly includes a compressor, a four-way valve, a heat exchanger and a first heat exchanger interlayer, a second heat exchanger interlayer and a third heat exchanger interlayer, and the compressor, the four-way valve, the heat exchanger, the first heat exchanger interlayer, the second heat exchanger interlayer and the third heat exchanger interlayer form a heat exchange circuit, and the first heat exchanger The interlayer, the second heat exchanger interlayer and the third heat exchanger interlayer are connected in parallel on the heat exchange circuit; the first heat exchanger interlayer is separated by a photovoltaic panel layer and a battery layer, the second heat exchanger interlayer is separated by a battery layer and a controller inverter layer, the third heat exchanger interlayer is separated by a controller inverter layer and a heat pump layer, and the compressor, the four-way valve and the heat exchanger are located in the heat pump layer; the liquid inlet ends of the first heat exchanger interlayer, the second heat exchanger interlayer and the third heat exchanger interlayer are all provided with electronic expansion valves; the photovoltaic panel layer, the battery layer and the controller inverter layer are all provided with temperature sensors for detecting the temperature of each layer.

[0009] It can be seen from the above scheme that the household photovoltaic system of the present invention is provided with a heat pump assembly, and the photovoltaic panel layer, the battery layer and the controller inverter layer are separated by the first heat exchanger interlayer, the second heat exchanger interlayer and the third heat exchanger interlayer in the heat pump assembly. The first heat exchanger interlayer, the second heat exchanger interlayer and the third heat exchanger interlayer can be used to control the temperature of the photovoltaic panel layer, the battery layer and the controller inverter layer respectively, so as to meet the temperature control requirements of each layer, reduce the influence of excessively high temperature and excessively low temperature on the power generation efficiency of the photovoltaic panel, and ensure the temperature rise reliability of the inverter system and the battery.

[0010] In a further scheme, at least one of the first heat exchanger interlayer, the second heat exchanger interlayer and the third heat exchanger interlayer is provided with a first end collecting pipe, a second end collecting pipe and a microchannel group, the first end of the microchannel in the microchannel group is connected to the first end collecting pipe, the second end of the microchannel is connected to the second end collecting pipe, the first end collecting pipe is also connected to the heat exchanger through an electronic expansion valve, and the second end collecting pipe is also connected to one end of the four-way valve.

[0011] It can be seen that the first heat exchanger interlayer, the second heat exchanger interlayer and the third heat exchanger interlayer can have the advantages of high heat transfer efficiency, not easy to be blocked, compact structure, light weight, energy saving and environmental protection by setting up microchannel groups for heat exchange.

[0012] In a further solution, a first fan and a second fan are arranged in the battery layer, the first fan is located at the top of the battery layer, and the second fan is located at the bottom of the battery layer; a third fan is arranged in the controller inverter layer, and the third fan is located at the bottom of the controller inverter layer.

[0013] It can be seen that by setting fans in the battery layer and the controller inverter layer, the fans can be used to speed up the heat exchange effect and improve the accuracy of temperature control.

[0014] In a further solution, the battery layer and the controller inverter layer are sealed.

[0015] It can be seen that the battery layer and the controller inverter layer are sealed, and no condensation water will be generated inside, which can ensure the safety of the circuit.

[0016] In order to achieve the second purpose of the present invention, the thermal management control method of a household photovoltaic system provided by the present invention includes: controlling the heat pump component to enter a cooling mode or a heating mode; obtaining the current ambient temperature, the current photovoltaic panel temperature of the photovoltaic panel layer, the current battery layer temperature of the battery layer, and the current control layer temperature of the controller inverter layer; controlling the heat pump component to adjust the temperature of the photovoltaic panel layer, the battery layer, and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature, so that the temperatures of the photovoltaic panel layer, the battery layer, and the controller inverter layer are within the preset temperature range corresponding to each layer.

[0017] It can be seen from the above scheme that the thermal management control method of the photovoltaic system of the present invention controls the heat pump component to adjust the temperature of the photovoltaic panel layer, battery layer, and controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature when the heat pump component enters the cooling mode or the heating mode. Each layer can be kept within the corresponding preset temperature range to meet the temperature control requirements of each layer, reduce the impact of excessively high and low temperatures on the power generation efficiency of the photovoltaic panel, and ensure the temperature rise reliability of the inverter system and the battery.

[0018] In a further scheme, the steps of controlling the heat pump component to adjust the temperature of the photovoltaic panel layer, the battery layer and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature include: obtaining the basic frequency corresponding to the compressor at the current ambient temperature; obtaining the first additive frequency corresponding to the compressor at the current photovoltaic panel temperature, the second additive frequency corresponding to the compressor at the current photovoltaic panel temperature and the third additive frequency corresponding to the compressor at the current control layer temperature; adding the basic frequency, the first additive frequency, the second additive frequency and the third additive frequency to obtain the total control frequency of the compressor, and controlling the operation of the compressor with the total control frequency.

[0019] It can be seen from this that when controlling the compressor frequency, the basic frequency corresponding to the compressor is determined according to the current ambient temperature, and the corresponding additive frequency is determined according to the current temperature of each layer, so that the sum of the basic frequency and the additive frequency of each layer is used as the total control frequency to control the operation of the compressor, which can help improve the accuracy of compressor frequency control and reduce energy consumption.

[0020] In a further scheme, the step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer, the battery layer and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature also includes: obtaining a first opening of the electronic expansion valve corresponding to the first heat exchanger interlayer at the current ambient temperature and the current photovoltaic panel temperature, open-loop controlling the opening of the electronic expansion valve corresponding to the first heat exchanger interlayer according to the first opening, and after a first preset open-loop control period, controlling the opening of the electronic expansion valve corresponding to the first heat exchanger interlayer with a first preset closed-loop control logic; obtaining the first opening of the electronic expansion valve corresponding to the first heat exchanger interlayer at the current ambient temperature and the current photovoltaic panel temperature. The second opening of the electronic expansion valve corresponding to the second heat exchanger interlayer at the current ambient temperature and the current battery layer temperature is obtained, and the opening of the electronic expansion valve is open-loop controlled according to the second opening. After the open-loop control is performed for a second preset time, the opening of the electronic expansion valve corresponding to the second heat exchanger interlayer is controlled with a second preset closed-loop control logic; the third opening of the electronic expansion valve corresponding to the third heat exchanger interlayer is obtained at the current ambient temperature and the current photovoltaic panel temperature, and the opening of the electronic expansion valve is open-loop controlled according to the third opening. After the open-loop control is performed for a third preset time, the opening of the electronic expansion valve corresponding to the third heat exchanger interlayer is controlled with a third preset closed-loop control logic.

[0021] It can be seen that since the operating temperatures required by the photovoltaic panel layer, battery layer and controller inverter layer are different, the temperature required by each layer can be adjusted by controlling the opening of the electronic expansion valve of each layer. Therefore, the accuracy of temperature control can be improved by controlling the opening of the electronic expansion valve according to the current ambient temperature and the temperature of each layer.

[0022] In a further scheme, the first preset closed-loop control logic includes: dynamically adjusting the opening of the electronic expansion valve corresponding to the first heat exchanger interlayer so that the current photovoltaic panel temperature is within the first preset temperature range; and / or the second preset closed-loop control logic includes: dynamically adjusting the opening of the electronic expansion valve corresponding to the second heat exchanger interlayer so that the current battery layer temperature is within the second preset temperature range; and / or the third preset closed-loop control logic includes: dynamically adjusting the opening of the electronic expansion valve corresponding to the third heat exchanger interlayer so that the current control layer temperature is within the third preset temperature range.

[0023] It can be seen that by controlling the opening of the electronic expansion valve in a closed loop, the target temperature of each layer can be adjusted faster and better, ensuring the stability of the temperature of each layer.

[0024] In a further scheme, a first fan and a second fan are arranged in the battery layer, the first fan is located at the top of the battery layer, and the second fan is located at the bottom of the battery layer; a third fan is arranged in the controller inverter layer, and the third fan is located at the bottom of the controller inverter layer; the step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer, the battery layer and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature also includes: obtaining the first speed of the first fan and the second speed of the second fan at the current ambient temperature and the current battery layer temperature, controlling the first fan according to the first speed, and controlling the second fan according to the second speed; obtaining the third speed of the third fan at the current ambient temperature and the current control layer temperature, and controlling the third fan according to the third speed.

[0025] It can be seen that by setting fans in the battery layer and the controller inverter layer, the fans can be used to accelerate the heat exchange effect. At the same time, the speed of each fan can be controlled according to the current ambient temperature and the temperature of each layer to improve the accuracy of temperature control.

[0026] In a further scheme, the heat pump layer is provided with a fourth temperature sensor for detecting the exhaust temperature of the compressor; the step of controlling the heat pump component to adjust the temperature of the photovoltaic panel layer, the battery layer, and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature also includes: when the total control frequency of the compressor is greater than the preset frequency, if the exhaust temperature is less than the first preset exhaust temperature, all the opened electronic expansion valves are controlled to gradually decrease the opening with the first preset degree until the exhaust temperature is greater than the second preset exhaust temperature, wherein the second preset exhaust temperature is greater than the first preset exhaust temperature; when the compressor is running, if the exhaust temperature is greater than the third preset exhaust temperature, all the opened electronic expansion valves are controlled to gradually increase the opening with the second preset degree until the exhaust temperature is less than the fourth preset exhaust temperature, wherein the third preset exhaust temperature is greater than the second preset exhaust temperature, and the fourth preset exhaust temperature is less than the third preset exhaust temperature.

[0027] It can be seen that if the exhaust temperature of the compressor is too low, there will be a phenomenon of liquid in the air, and liquid hammer may occur. If the exhaust temperature is too high, the life of the motor winding will be reduced. Therefore, it is necessary to control the opening of the electronic expansion valve of each layer according to the exhaust temperature to adjust the exhaust temperature of the compressor. When adjusting the opening of the electronic expansion valve, all the electronic expansion valves are activated together to ensure that the temperature fluctuation of each layer will not be too large, and the stability of the temperature of each layer is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic block diagram of the system structure of an embodiment of a household photovoltaic system of the present invention.

[0029] Figure 2It is a schematic structural diagram of the first heat exchanger interlayer in an embodiment of a household photovoltaic system of the present invention.

[0030] Figure 3 It is a flow chart of an embodiment of a thermal management control method for a household photovoltaic system of the present invention.

[0031] The present invention is further described below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0032] Household photovoltaic system implementation example: In this embodiment, see Figure 1 The household photovoltaic system includes a photovoltaic panel layer 1, a battery layer 2, a controller inverter layer 3, a heat pump layer 4 and a heat pump assembly. The photovoltaic panel layer 1, the battery layer 2, the controller inverter layer 3 and the heat pump layer 4 are arranged in sequence from top to bottom in the vertical direction. The photovoltaic panel layer 1 is used to install photovoltaic panels, the battery layer 2 is used to install energy storage batteries, the energy storage batteries are used to supply power to the household photovoltaic system and to the external circuit, and the controller inverter layer 3 is used to install the control circuit. Preferably, the battery layer 2 and the controller inverter layer 3 are sealed. The battery layer 2 and the controller inverter layer 3 are sealed, and no condensation water is generated inside, which can ensure the safety of the circuit.

[0033] In this embodiment, the heat pump assembly includes a compressor 51, a four-way valve 52, a heat exchanger 53, a first heat exchanger interlayer 54, a second heat exchanger interlayer 55, and a third heat exchanger interlayer 56. The compressor 51, the four-way valve 52, the heat exchanger 53, the first heat exchanger interlayer 54, the second heat exchanger interlayer 55, and the third heat exchanger interlayer 56 form a heat exchange loop, and the first heat exchanger interlayer 54, the second heat exchanger interlayer 55, and the third heat exchanger interlayer 56 are connected in parallel to the heat exchange loop. The first heat exchanger interlayer 54 is separated from the photovoltaic panel layer 1 and the battery layer 2, the second heat exchanger interlayer 55 is separated from the battery layer 2 and the controller inverter layer 3, and the third heat exchanger interlayer 56 is separated from the controller inverter layer 3 and the heat pump layer 4. The compressor 51, the four-way valve 52, and the heat exchanger 53 are located in the heat pump layer 4.

[0034] In this embodiment, see Figure 2The first heat exchanger interlayer 54 is provided with an electronic expansion valve 541, a first end collecting pipe 542, a second end collecting pipe 543 and a microchannel group 544. The first end of the microchannel in the microchannel group 544 is connected to the first end collecting pipe 542, and the second end of the microchannel is connected to the second end collecting pipe 543. The first end collecting pipe 542 is also connected to the heat exchanger 53 through the electronic expansion valve 541, and the second end collecting pipe 543 is connected to one end of the four-way valve 52 through the collecting pipe 57. The structures of the second heat exchanger interlayer 55 and the third heat exchanger interlayer 56 are the same as those of the first heat exchanger interlayer 54, and will not be repeated here. The first heat exchanger interlayer 54, the second heat exchanger interlayer 55 and the third heat exchanger interlayer 56 perform heat exchange by setting the microchannel group 544, which can have the advantages of high heat transfer efficiency, not easy to be blocked, compact structure, light weight, energy saving and environmental protection.

[0035] In this embodiment, the photovoltaic panel layer 1, the battery layer 2 and the controller inverter layer 3 are all provided with temperature sensors for detecting the temperature of each layer. Specifically, the photovoltaic panel layer 1 is provided with a first temperature sensor 6 for detecting the temperature of the photovoltaic panel layer 1, the battery layer 2 is provided with a second temperature sensor 7 for detecting the internal temperature of the battery layer 2, and the controller inverter layer 3 is provided with a third temperature sensor 8 for detecting the internal temperature of the controller inverter layer 3. In addition, the heat pump layer 4 is provided with a fourth temperature sensor (not shown) for detecting the exhaust temperature of the compressor 51 and a fifth temperature sensor (not shown) for detecting the ambient temperature of the household photovoltaic system.

[0036] In this embodiment, the battery layer 2 is provided with a first fan 21 and a second fan 22, the first fan 21 is located at the top of the battery layer 2, and the second fan 22 is located at the bottom of the battery layer 2. The controller inverter layer 3 is provided with a third fan 31, and the third fan 31 is located at the bottom of the controller inverter layer 3. Preferably, the first fan 21, the second fan 22 and the third fan 31 all blow air toward the position where heat dissipation is required in the corresponding layer. By arranging fans in the battery layer 2 and the controller inverter layer 3, the fans can be used to accelerate the heat exchange effect and improve the accuracy of temperature control.

[0037] In order to better reflect the working principle of the household photovoltaic system of the present invention, the thermal management control method of the household photovoltaic system is described below.

[0038] In this embodiment, see Figure 3 When the thermal management control method of the household photovoltaic system is working, step S1 is first performed to control the heat pump component to enter the cooling mode or the heating mode. The cooling mode or the heating mode can be automatically controlled according to the range of the current ambient temperature, or can be manually controlled.

[0039] After entering the cooling mode or heating mode, execute step S2 to obtain the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature. In order to facilitate the temperature control of the photovoltaic panel layer 1, the battery layer 2 and the controller inverter layer 3, the temperature is adjusted according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature. The current ambient temperature can be obtained through the fifth temperature sensor, the current photovoltaic panel temperature can be obtained through the first temperature sensor 6, the current battery layer temperature can be obtained through the second temperature sensor 7, and the current control layer temperature can be obtained through the third temperature sensor 8.

[0040] After obtaining the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature, step S3 is executed to control the heat pump component to adjust the temperature of the photovoltaic panel layer 1, the battery layer 2 and the controller inverter layer 3 according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature, so that the temperature of the photovoltaic panel layer 1, the battery layer 2 and the controller inverter layer 3 is within the preset temperature range corresponding to each layer. According to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature, the heat pump component is controlled to adjust the temperature of the photovoltaic panel layer 1, the battery layer 2 and the controller inverter layer 3, so that each layer is within the corresponding preset temperature range, meeting the temperature control requirements of each layer, reducing the impact of excessively high and low temperatures on the power generation efficiency of the photovoltaic panel, and ensuring the temperature rise reliability of the inverter system and the battery.

[0041] In this embodiment, the step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer 1, the battery layer 2 and the controller inverter layer 3 according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature includes: obtaining the basic frequency corresponding to the compressor 51 at the current ambient temperature; obtaining the first additive frequency corresponding to the compressor 51 at the current photovoltaic panel temperature, the second additive frequency corresponding to the compressor 51 at the current photovoltaic panel temperature and the third additive frequency corresponding to the compressor 51 at the current control layer temperature; adding the basic frequency, the first additive frequency, the second additive frequency and the third additive frequency to obtain the total control frequency of the compressor 51, and controlling the operation of the compressor 51 with the total control frequency. The basic frequency corresponding to the compressor 51 is determined according to the current ambient temperature, and the corresponding additive frequency is determined according to the current temperature of each layer, so that the sum of the basic frequency and the additive frequency of each layer is used as the total control frequency to control the operation of the compressor 51, which can help improve the accuracy of the frequency control of the compressor 51 and reduce energy consumption.

[0042] In an example of compressor frequency control, when entering the cooling mode, when the current ambient temperature Tw is 10℃<Tw≤20℃, the basic frequency is 0. At this time, if the current photovoltaic panel temperature Tg is greater than 50℃, the first added frequency is 15+(Tg-50)Hz; if the current photovoltaic panel temperature Tg is less than or equal to 50℃, the first added frequency is 0; if the current battery layer temperature Td is greater than 40℃, the second added frequency is 20+ (Td-40)Hz; if the current battery layer temperature Td is less than or equal to 40℃, the second added frequency is 0; if the current control layer temperature Tk is greater than 40℃, the third added frequency is 30+(Tk-40)Hz; if the current control layer temperature Tk is less than or equal to 40℃, the third added frequency is 0. When the current ambient temperature Tw is 20℃<Tw≤45℃, the base frequency is 40Hz. At this time, if the current photovoltaic panel temperature Tg is greater than 50℃, the first added frequency is 5+(Tg-50)Hz, if the current photovoltaic panel temperature Tg is less than or equal to 50℃, the first added frequency is 0, if the current battery layer temperature Td is greater than 40℃, the second added frequency is 10+ (Td-40)Hz, if the current battery layer temperature Td is less than or equal to 40℃, the second added frequency is 0, if the current control layer temperature Tk is greater than 50℃, the third added frequency is 20+(Tk-50)Hz, if the current control layer temperature Tk is less than or equal to 50℃, the third added frequency is 0. When the current ambient temperature Tw is 45℃<Tw, the total control frequency of the compressor 51 is at the preset maximum frequency.

[0043] When entering the heating mode, when the current ambient temperature Tw is at 0℃<Tw≤10℃, the basic frequency is 0. At this time, the first additive frequency is 0. If the current battery layer temperature Td is less than 20℃, the second additive frequency is 10+(20-Td)Hz. If the current battery layer temperature Td is greater than or equal to 20℃, the second additive frequency is 0. The third additive frequency is 0. When the current ambient temperature Tw is Tw≤0℃, the base frequency is 40Hz. At this time, if the current photovoltaic panel temperature Tg is less than 0℃, the first additive frequency is 20+(0-Tg)Hz; if the current photovoltaic panel temperature Tg is greater than or equal to 0℃, the first additive frequency is 0; if the current battery layer temperature Td is less than 20℃, the second additive frequency is 10+ (20-Td)Hz; if the current battery layer temperature Td is greater than or equal to 20℃, the second additive frequency is 0; if the current control layer temperature Tk is less than 0℃, the third additive frequency is 20+(0-Tk)Hz; if the current control layer temperature Tk is greater than or equal to 0℃, the third additive frequency is 0.

[0044] In this embodiment, the step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer 1, the battery layer 2 and the controller inverter layer 3 according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature also includes: obtaining a first opening of the electronic expansion valve 541 corresponding to the first heat exchanger interlayer 54 at the current ambient temperature and the current photovoltaic panel temperature, open-loop controlling the opening of the electronic expansion valve 541 corresponding to the first heat exchanger interlayer 54 according to the first opening, and after the open-loop control for a first preset time, controlling the opening of the electronic expansion valve 541 corresponding to the first heat exchanger interlayer 54 with a first preset closed-loop control logic; obtaining the opening of the second heat exchanger interlayer 54 at the current ambient temperature and the current battery layer temperature. 55, and control the opening of the electronic expansion valve 541 corresponding to the second heat exchanger interlayer 55 in an open-loop manner according to the second opening. After the open-loop control is performed for a second preset period of time, the opening of the electronic expansion valve 541 corresponding to the second heat exchanger interlayer 55 is controlled by a second preset closed-loop control logic; obtain the third opening of the electronic expansion valve 541 corresponding to the third heat exchanger interlayer 56 under the current ambient temperature and the current photovoltaic panel temperature, and control the opening of the electronic expansion valve 541 corresponding to the third heat exchanger interlayer 56 in an open-loop manner according to the third opening. After the open-loop control is performed for a third preset period of time, the opening of the electronic expansion valve 541 corresponding to the third heat exchanger interlayer 56 is controlled by a third preset closed-loop control logic.

[0045] In an example of controlling an electronic expansion valve, when entering the cooling mode, the current ambient temperature Tw is between 10℃<Tw≤20℃, at this time, if the current photovoltaic panel temperature Tg is greater than 50℃, the first opening is 150+(Tg-50)*4, if the current photovoltaic panel temperature Tg is less than or equal to 50℃, the first opening is 0; if the current battery layer temperature Td is greater than 40℃, the second opening is 120+(Td-40)*3, if the current battery layer temperature Td is less than or equal to 40℃, the second opening is 0; if the current control layer temperature Tk is greater than 40℃, the third opening is 150+(Tk-40)*2, if the current control layer temperature Tk is less than or equal to 40℃, the third opening is 0. When the current ambient temperature Tw is 20℃<Tw, at this time, if the current photovoltaic panel temperature Tg is greater than 50℃, the first opening is 150+(Tg-50)*6, if the current photovoltaic panel temperature Tg is less than or equal to 50℃, the first opening is 0; if the current battery layer temperature Td is greater than 40℃, the second opening is 120+(Td-40)*6, if the current battery layer temperature Td is less than or equal to 40℃, the second opening is 0; if the current control layer temperature Tk is greater than 50℃, the third opening is 150+(Tk-40)*6, if the current control layer temperature Tk is less than or equal to 40℃, the third opening is 0.

[0046] When entering the heating mode, when the current ambient temperature Tw is at 0<Tw≤10℃, the first opening is 0; if the current battery layer temperature Td is less than 20℃, the second opening is 80+(20-Td); if the current battery layer temperature Td is greater than or equal to 20℃, the second opening is 0; the third opening is 0. When the current ambient temperature Tw is Tw≤0℃, at this time, if the current photovoltaic panel temperature Tg is less than 0℃, the first opening is 90+(0-Tg)*5, if the current photovoltaic panel temperature Tg is greater than or equal to 0℃, the first opening is 0; if the current battery layer temperature Td is less than 20℃, the second opening is 90+(20-Td)*3, if the current battery layer temperature Td is greater than or equal to 20℃, the second opening is 0; if the current control layer temperature Tk is less than 0℃, the third opening is 90+(0-Tk)*5, if the current control layer temperature Tk is greater than or equal to 0℃, the third opening is 0.

[0047] The first preset closed-loop control logic includes: dynamically adjusting the opening of the electronic expansion valve 541 corresponding to the first heat exchanger interlayer 54, so that the current photovoltaic panel temperature is within the first preset temperature range, wherein the first preset temperature range can be preset according to experimental data. The second preset closed-loop control logic includes: dynamically adjusting the opening of the electronic expansion valve 541 corresponding to the second heat exchanger interlayer 55, so that the current battery layer temperature is within the second preset temperature range, wherein the second preset temperature range can be preset according to experimental data. The third preset closed-loop control logic includes: dynamically adjusting the opening of the electronic expansion valve 541 corresponding to the third heat exchanger interlayer 56, so that the current control layer temperature is within the third preset temperature range, wherein the third preset temperature range can be preset according to experimental data. By closed-loop controlling the opening of the electronic expansion valve 541, the target temperature of each layer can be adjusted faster and better to ensure the stability of the temperature of each layer.

[0048] In this embodiment, the step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer 1, the battery layer 2 and the controller inverter layer 3 according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature also includes: obtaining the first rotation speed of the first fan 21 and the second rotation speed of the second fan 22 at the current ambient temperature and the current battery layer temperature, controlling the first fan 21 according to the first rotation speed, and controlling the second fan 22 according to the second rotation speed; obtaining the third rotation speed of the third fan 31 at the current ambient temperature and the current control layer temperature, and controlling the third fan 31 according to the third rotation speed. By arranging fans in the battery layer 2 and the controller inverter layer 3, the fans can be used to accelerate the heat exchange effect. At the same time, the rotation speed of each fan is controlled according to the current ambient temperature and the temperature of each layer, thereby improving the accuracy of temperature control.

[0049] In an example of controlling the fan speed, when entering the cooling mode, the current ambient temperature Tw is 10℃<Tw≤20℃, at this time, if the current battery layer temperature Td is greater than 40℃, the first speed is 400 rpm, and the second speed is 800 rpm; if the current battery layer temperature Td is less than or equal to 40℃, the first speed is 0, and the second speed is 0; if the current control layer temperature Tk is greater than 40℃, the third speed is 600 rpm; if the current control layer temperature Tk is less than or equal to 40℃, the speed is 0. When the current ambient temperature Tw is 20℃<Tw, at this time, if the current battery layer temperature Td is greater than 40℃, the first speed is 1000 rpm, and the second speed is 1000 rpm; if the current battery layer temperature Td is less than or equal to 40℃, the first speed is 0, and the second speed is 0; if the current control layer temperature Tk is greater than 50℃, the third speed is 1000 rpm; if the current control layer temperature Tk is less than or equal to 40℃, the third speed is 0.

[0050] When entering the heating mode, when the current ambient temperature Tw is 0<Tw≤10℃, at this time, if the current battery layer temperature Td is less than 20℃, the first speed is 800 rpm, the second speed is 400 rpm, if the current battery layer temperature Td is greater than or equal to 20℃, the first speed is 0, the second speed is 0; if the current control layer temperature Tk is greater than 60℃, the third speed is 600rpm, if the current control layer temperature Tk is less than or equal to 60℃, the speed is 0. When the current ambient temperature Tw is ≤0℃, at this time, if the current battery layer temperature Td is less than 20℃, the first speed is 1000 rpm, the second speed is 1000 rpm, if the current battery layer temperature Td is greater than or equal to 20℃, the first speed is 0, the second speed is 0; if the current control layer temperature Tk is less than 0℃, the third speed is 8000 rpm, if the current control layer temperature Tk is greater than or equal to 0℃, the third speed is 0.

[0051] In this embodiment, the step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer 1, the battery layer 2, and the controller inverter layer 3 according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature also includes: when the total control frequency of the compressor 51 is greater than the preset frequency, if the exhaust temperature is less than the first preset exhaust temperature, all the opened electronic expansion valves 541 are controlled to gradually decrease the opening with the first preset opening until the exhaust temperature is greater than the second preset exhaust temperature, wherein the second preset exhaust temperature is greater than the first preset exhaust temperature; when the compressor 51 is running, if the exhaust temperature is greater than the third preset exhaust temperature, all the opened electronic expansion valves 541 are controlled to gradually increase the opening with the second preset opening until the exhaust temperature is less than the fourth preset exhaust temperature, wherein the third preset exhaust temperature is greater than the second preset exhaust temperature, and the fourth preset exhaust temperature is less than the third preset exhaust temperature. Among them, the preset frequency, the first preset exhaust temperature, the second preset exhaust temperature, the third preset exhaust temperature and the fourth preset exhaust temperature can be pre-set according to experimental data. Preferably, the preset frequency is 30Hz, the first preset exhaust temperature is 40°C, the second preset exhaust temperature is 50°C, the third preset exhaust temperature is 100°C, and the fourth preset exhaust temperature is 85°C.

[0052] If the exhaust temperature of the compressor 51 is too low, liquid may be carried in the air, which may cause liquid hammer, and if the exhaust temperature is too high, the life of the motor winding will be reduced. Therefore, the opening of the electronic expansion valve 541 of each layer is controlled according to the exhaust temperature to adjust the exhaust temperature of the compressor 51. When adjusting the opening of the electronic expansion valve 541, all valves are activated together to ensure that the temperature fluctuation of each layer is not too large, and the stability of the temperature of each layer is guaranteed.

[0053] From the above, it can be seen that the household photovoltaic system of the present invention is provided with a heat pump assembly, and the photovoltaic panel layer 1, the battery layer 2 and the controller inverter layer 3 are separated by the first heat exchanger interlayer 54, the second heat exchanger interlayer 55 and the third heat exchanger interlayer 56 in the heat pump assembly. The first heat exchanger interlayer 54, the second heat exchanger interlayer 55 and the third heat exchanger interlayer 56 can be used to control the temperature of the photovoltaic panel layer 1, the battery layer 2 and the controller inverter layer 3 respectively, so as to meet the temperature control requirements of each layer, reduce the influence of excessively high and low temperatures on the power generation efficiency of the photovoltaic panel, and ensure the temperature rise reliability of the inverter system and the battery.

[0054] It should be noted that the above are only preferred embodiments of the present invention, but the design concept of the invention is not limited thereto, and any non-substantial modifications made to the present invention using this concept also fall within the protection scope of the present invention.

Claims

1. A household photovoltaic system, characterized in that: It includes a photovoltaic panel layer, a battery layer, a controller inverter layer, a heat pump layer and a heat pump assembly, wherein the photovoltaic panel layer, the battery layer, the controller inverter layer and the heat pump layer are arranged in sequence from top to bottom along the vertical direction; The heat pump assembly comprises a compressor, a four-way valve, a heat exchanger, and a first heat exchanger interlayer, a second heat exchanger interlayer, and a third heat exchanger interlayer, wherein the compressor, the four-way valve, the heat exchanger, the first heat exchanger interlayer, the second heat exchanger interlayer, and the third heat exchanger interlayer form a heat exchange loop, and the first heat exchanger interlayer, the second heat exchanger interlayer, and the third heat exchanger interlayer are connected in parallel to the heat exchange loop; The first heat exchanger interlayer separates the photovoltaic panel layer and the battery layer, the second heat exchanger interlayer separates the battery layer and the controller inverter layer, the third heat exchanger interlayer separates the controller inverter layer and the heat pump layer, and the compressor, the four-way valve and the heat exchanger are located in the heat pump layer; The liquid inlet ends of the first heat exchanger interlayer, the second heat exchanger interlayer and the third heat exchanger interlayer are all provided with electronic expansion valves; The photovoltaic panel layer, the battery layer and the controller inverter layer are all provided with temperature sensors for detecting the temperature of each layer.

2. The household photovoltaic system according to claim 1, characterized in that: At least one of the first heat exchanger interlayer, the second heat exchanger interlayer and the third heat exchanger interlayer is provided with a first end collecting pipe, a second end collecting pipe and a microchannel group, the first end of the microchannel in the microchannel group is connected to the first end collecting pipe, the second end of the microchannel is connected to the second end collecting pipe, the first end collecting pipe is also connected to the heat exchanger through the electronic expansion valve, and the second end collecting pipe is also connected to one end of the four-way valve.

3. The household photovoltaic system according to claim 1 or 2, characterized in that: A first fan and a second fan are arranged in the battery layer, the first fan is located at the top of the battery layer, and the second fan is located at the bottom of the battery layer; A third fan is arranged in the controller inverter layer, and the third fan is located at the bottom of the controller inverter layer.

4. The household photovoltaic system according to claim 3, characterized in that: The battery layer and the controller inverter layer are sealed.

5. A thermal management control method for a household photovoltaic system, characterized in that: The household photovoltaic system applies the household photovoltaic system described in claim 1; The method comprises: Controlling the heat pump assembly to enter a cooling mode or a heating mode; Acquire the current ambient temperature, the current photovoltaic panel temperature of the photovoltaic panel layer, the current battery layer temperature of the battery layer, and the current control layer temperature of the controller inverter layer; The heat pump component is controlled according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature to adjust the temperature of the photovoltaic panel layer, the battery layer and the controller inverter layer, so that the temperatures of the photovoltaic panel layer, the battery layer and the controller inverter layer are within the preset temperature range corresponding to each layer.

6. The thermal management control method of a household photovoltaic system according to claim 5, characterized in that: The step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer, the battery layer and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature comprises: Acquire the fundamental frequency corresponding to the compressor at the current ambient temperature; Acquire a first addition frequency corresponding to the compressor at the current photovoltaic panel temperature, a second addition frequency corresponding to the compressor at the current photovoltaic panel temperature, and a third addition frequency corresponding to the compressor at the current control layer temperature; The basic frequency, the first additive frequency, the second additive frequency, and the third additive frequency are added together to obtain a total control frequency of the compressor, and the compressor is controlled to operate with the total control frequency.

7. The thermal management control method for a household photovoltaic system according to claim 5 or 6, characterized in that: The step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer, the battery layer and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature also includes: Acquire a first opening of the electronic expansion valve corresponding to the first heat exchanger interlayer at the current ambient temperature and the current photovoltaic panel temperature, perform open-loop control on the opening of the electronic expansion valve corresponding to the first heat exchanger interlayer according to the first opening, and after a first preset open-loop control period, control the opening of the electronic expansion valve corresponding to the first heat exchanger interlayer with a first preset closed-loop control logic; Obtaining a second opening of the electronic expansion valve corresponding to the second heat exchanger interlayer at the current ambient temperature and the current battery layer temperature, open-loop controlling the opening of the electronic expansion valve according to the second opening, and after a second preset open-loop control period, controlling the opening of the electronic expansion valve corresponding to the second heat exchanger interlayer with a second preset closed-loop control logic; Obtain the third opening of the electronic expansion valve corresponding to the third heat exchanger interlayer under the current ambient temperature and the current photovoltaic panel temperature, open-loop control the opening of the electronic expansion valve according to the third opening, and after the open-loop control for a third preset time, control the opening of the electronic expansion valve corresponding to the third heat exchanger interlayer with a third preset closed-loop control logic.

8. The thermal management control method of a household photovoltaic system according to claim 7, characterized in that: The first preset closed-loop control logic includes: dynamically adjusting the opening of the electronic expansion valve corresponding to the first heat exchanger interlayer so that the current photovoltaic panel temperature is within a first preset temperature range; and / or The second preset closed-loop control logic includes: dynamically adjusting the opening of the electronic expansion valve corresponding to the second heat exchanger interlayer so that the current battery layer temperature is within a second preset temperature range; and / or The third preset closed-loop control logic includes: dynamically adjusting the opening of the electronic expansion valve corresponding to the third heat exchanger interlayer so that the current control layer temperature is within a third preset temperature range.

9. The thermal management control method for a household photovoltaic system according to claim 5 or 6, characterized in that: The battery layer is provided with a first fan and a second fan, the first fan is located at the top of the battery layer, and the second fan is located at the bottom of the battery layer; the controller inverter layer is provided with a third fan, and the third fan is located at the bottom of the controller inverter layer; The step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer, the battery layer and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature and the current control layer temperature also includes: Acquire a first rotation speed of the first fan and a second rotation speed of the second fan at the current ambient temperature and the current battery layer temperature, control the first fan according to the first rotation speed, and control the second fan according to the second rotation speed; Acquire a third rotational speed of the third fan under the current ambient temperature and the current control layer temperature, and control the third fan according to the third rotational speed.

10. The thermal management control method for a household photovoltaic system according to claim 5 or 6, characterized in that: The heat pump layer is provided with a fourth temperature sensor for detecting the exhaust temperature of the compressor; The step of controlling the heat pump assembly to adjust the temperature of the photovoltaic panel layer, the battery layer, and the controller inverter layer according to the current ambient temperature, the current photovoltaic panel temperature, the current battery layer temperature, and the current control layer temperature also includes: When the total control frequency of the compressor is greater than the preset frequency, if the exhaust temperature is less than the first preset exhaust temperature, all opened electronic expansion valves are controlled to gradually decrease the opening at the first preset opening until the exhaust temperature is greater than the second preset exhaust temperature, wherein the second preset exhaust temperature is greater than the first preset exhaust temperature; When the compressor is running, if the exhaust temperature is greater than the third preset exhaust temperature, all opened electronic expansion valves are controlled to gradually increase the opening with the second preset opening until the exhaust temperature is less than the fourth preset exhaust temperature, wherein the third preset exhaust temperature is greater than the second preset exhaust temperature, and the fourth preset exhaust temperature is less than the third preset exhaust temperature.

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