Liquid-cooled light storage charging system and thermal management method thereof

Abstract

The application discloses a liquid-cooled light storage and charging system and a heat management method thereof, and relates to the technical field of energy storage and charging, and specifically relates to a liquid-cooled light storage and charging system and a heat management method thereof. The liquid-cooled light storage and charging system comprises a battery cabinet, an electrical equipment cabinet, a liquid cooling machine, a first three-way valve, a second three-way valve, a liquid cooling pipeline and an EMS control subsystem; the liquid cooling machine comprises a water outlet and a water return port; the water outlet, the first three-way valve, the battery cabinet, the electrical equipment cabinet, the second three-way valve and the water return port are sequentially connected through the liquid cooling pipeline to form a refrigeration circulation loop; the water outlet, the first three-way valve, the electrical equipment cabinet, the battery cabinet, the second three-way valve and the water return port are sequentially connected through the liquid cooling pipeline to form a heating circulation loop; the first three-way valve and the second three-way valve are both connected with the EMS control subsystem for control, and the liquid cooling machine is a cold and hot all-in-one machine. The application adopts the heat management scheme that the battery cabinet and the electrical equipment cabinet in the whole light storage and charging system are uniformly refrigerated and heated by the liquid cooling machine, and each sub-component participates in the control in the heat management process, so that the overall energy consumption of the system is effectively reduced, and the utilization rate of the water cooling system is improved.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic energy storage system technology, and in particular to a liquid-cooled photovoltaic energy storage and charging system and its thermal management method. Background Technology

[0002] With the rapid development of electric vehicles, using high-power DC charging equipment in conjunction with energy storage batteries and photovoltaic systems to expand the DC capacity of the power grid and create integrated photovoltaic-energy storage-charging systems has become a trend. This aims to increase charging power and reduce grid distribution capacity requirements. To maintain the stable operation of the photovoltaic-energy storage-charging system, avoid grid interference, and ensure normal charging for every vehicle, the system needs to be configured with appropriate charging power, energy storage capacity, and photovoltaic system specifications. Furthermore, due to the numerous components within the system, the requirements for heating and heat dissipation are even higher. Its continuous and stable operation relies heavily on effective thermal management. With the development of liquid cooling technology, its high heat dissipation efficiency, low energy consumption, and high performance are increasingly being applied to the thermal management of photovoltaic-energy storage-charging systems, effectively reducing energy loss and increasing profitability.

[0003] Existing photovoltaic-storage-charging systems mainly consist of battery systems, energy storage converters (PCS), DC-DC converters, photovoltaics, liquid chillers, and other electrical equipment. Currently, only the battery system uses liquid cooling for thermal management. Power-type electrical components such as the PCS and DC-DC converters still use air cooling, employing internal fans for heating or heat dissipation. These systems are controlled separately, resulting in high energy consumption, low performance, and high noise. Furthermore, the thermal management of photovoltaic-storage systems involves both liquid cooling and separate air cooling, failing to form a complete integrated thermal management system, which also contributes to the overall high energy consumption of the site. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a liquid-cooled optical energy storage and charging system and its thermal management method, which effectively reduces overall energy consumption and improves water cooling utilization.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A liquid-cooled photovoltaic energy storage and charging system includes a battery cabinet, an electrical equipment cabinet, a liquid chiller, a first three-way valve, a second three-way valve, liquid cooling pipelines, and an EMS control subsystem.

[0007] The liquid cooler includes an outlet and an inlet;

[0008] The water outlet, the first three-way valve, the battery cabinet, the electrical equipment cabinet, the second three-way valve, and the water return outlet are sequentially connected through the liquid cooling pipeline to form a refrigeration cycle loop;

[0009] The water outlet, the first three-way valve, the electrical equipment cabinet, the battery cabinet, the second three-way valve, and the water return outlet are sequentially connected through the liquid cooling pipeline to form a heating circulation loop;

[0010] The first three-way valve, the second three-way valve, and the liquid chiller are all connected to the EMS control subsystem, and the liquid chiller is an integrated cooling and heating unit.

[0011] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows:

[0012] A thermal management method for a liquid-cooled optical energy storage and charging system, employing the aforementioned liquid-cooled optical energy storage and charging system, includes the following steps:

[0013] S0. Define the valve port of the first three-way valve connected to the outlet of the liquid chiller as A, the valve port connected to the electrical equipment cabinet as B, and the valve port connected to the battery cabinet as C. Define the valve port of the second three-way valve connected to the return water port of the liquid chiller as A, the valve port connected to the electrical equipment cabinet as B, and the valve port connected to the battery cabinet as C.

[0014] S1. Determine the system operating mode. If the system operating mode is cooling mode, proceed to step S2. If the system operating mode is heating mode, proceed to step S3.

[0015] S2, the EMS control subsystem controls the opening of ports A and C of the first three-way valve and the closing of port B, and controls the opening of ports A and B of the second three-way valve and the closing of port C. Then, the liquid chiller is started to send the cooled water out from the outlet and through the liquid cooling pipeline, it flows into the battery cabinet through ports A and C of the first three-way valve for a first heat exchange to cool the battery cells. The cooled water after the first heat exchange flows out of the battery cabinet through the liquid cooling pipeline and into the electrical equipment cabinet for a second heat exchange to cool the electrical components. The cooled water after the second heat exchange flows out of the electrical equipment cabinet through the liquid cooling pipeline and through ports B and A of the second three-way valve to flow back into the liquid chiller through the return port for recooling, thus repeating the cooling cycle.

[0016] S3. The EMS control subsystem controls the opening of valve ports A and B and the closing of valve port C of the first three-way valve, and controls the opening of valve ports A and C and the closing of valve port B of the second three-way valve. Then, the liquid chiller is started to send the heated water out of the outlet and through the liquid cooling pipeline through the first three-way valve through the first three-way valve through the first two three-way valves into the electrical equipment cabinet for a first cooling exchange to heat the electrical components. The heated water after the first cooling exchange flows out of the electrical equipment cabinet through the liquid cooling pipeline and into the battery cabinet for a second cooling exchange to heat the battery cells. The heated water after the second cooling exchange flows out of the battery cabinet through the liquid cooling pipeline and through the second three-way valve through the second three-way valve through the return water port back into the liquid chiller for reheating, thus replicating the heat cycle.

[0017] The beneficial effects of this invention are as follows: By replacing the traditional thermal management scheme that uses liquid cooling only for the battery system and air cooling for other power-type electrical components, a thermal management scheme that uses liquid chillers for both cooling and heating of the battery cabinets and electrical equipment cabinets in the entire photovoltaic-storage system is adopted. Within the entire system, liquid cooling pipelines and two three-way valves connect the liquid chiller, battery cabinet, and electrical equipment cabinet to form different cooling and heating loops. The EMS control subsystem controls the opening and closing of different ports of the two three-way valves to achieve cooling of the liquid chiller in the cooling loop. Water undergoes a primary heat exchange in the battery cabinet, followed by a secondary heat exchange in the electrical equipment cabinet before returning to the liquid chiller. This ensures that the water exchanged after effectively cooling the battery cells in the battery cabinet can further effectively cool the high-temperature resistant electrical components in the electrical equipment cabinet. Similarly, the heating water in the liquid chiller in the heating circulation loop undergoes a primary cooling exchange in the electrical equipment cabinet, followed by a secondary cooling exchange in the battery cabinet before returning to the liquid chiller. This ensures that the cooling water exchanged after effectively heating the power-type electrical components in the electrical equipment cabinet can further effectively heat the battery cells in the battery cabinet, ensuring the normal operation of the entire photovoltaic-storage system. Every sub-component participates in the control of the entire thermal management process, effectively reducing the overall system energy consumption and improving the utilization rate of the water cooling system. Attached Figure Description

[0018] Figure 1 This is a structural block diagram of a liquid-cooled optical energy storage and charging system according to an embodiment of the present invention;

[0019] Figure 2 This is a communication and control circuit diagram of a liquid-cooled optical energy storage and charging system according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the cooling cycle of a liquid-cooled optical energy storage and charging system according to an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the heating cycle of a liquid-cooled optical energy storage and charging system according to an embodiment of the present invention;

[0022] Figure 5This is an overall flowchart of a thermal management method for a liquid-cooled optical energy storage and charging system according to an embodiment of the present invention;

[0023] Figure 6 This is a flowchart illustrating a thermal management method for a liquid-cooled optical energy storage and charging system according to an embodiment of the present invention.

[0024] Label Explanation:

[0025] 1. Battery cabinet; 2. Electrical equipment cabinet; 21. DC-DC cabinet; 22. PCS cabinet; 23. Flow valve; 3. Liquid chiller; 4. First three-way valve; 5. Second three-way valve. Detailed Implementation

[0026] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0027] Please refer to Figures 1 to 4 A liquid-cooled photovoltaic energy storage and charging system includes a battery cabinet, an electrical equipment cabinet, a liquid chiller, a first three-way valve, a second three-way valve, liquid cooling pipelines, and an EMS control subsystem.

[0028] The liquid cooler includes an outlet and an inlet;

[0029] The water outlet, the first three-way valve, the battery cabinet, the electrical equipment cabinet, the second three-way valve, and the water return outlet are sequentially connected through the liquid cooling pipeline to form a refrigeration cycle loop;

[0030] The water outlet, the first three-way valve, the electrical equipment cabinet, the battery cabinet, the second three-way valve, and the water return outlet are sequentially connected through the liquid cooling pipeline to form a heating circulation loop;

[0031] The first three-way valve, the second three-way valve, and the liquid chiller are all connected to the EMS control subsystem, and the liquid chiller is an integrated cooling and heating unit.

[0032] As described above, the beneficial effects of this invention are as follows: By replacing the traditional thermal management scheme that uses liquid cooling only for the battery system and air cooling for other power-type electrical components, a thermal management scheme that uses a liquid chiller for both cooling and heating of the battery cabinet and electrical equipment cabinet in the entire photovoltaic-storage system is adopted. Within the entire system, the liquid chiller, battery cabinet, and electrical equipment cabinet are connected by liquid cooling pipelines and two three-way valves to form different cooling and heating loops. The EMS control subsystem controls the opening and closing of different valve ports of the two three-way valves to achieve liquid cooling in the cooling loop. The cooling water for the generator first undergoes heat exchange in the battery cabinet, then a second heat exchange in the electrical equipment cabinet before returning to the liquid chiller. This ensures that the water exchanged after effectively cooling the battery cells in the battery cabinet can further effectively cool the high-temperature resistant electrical components in the electrical equipment cabinet. Similarly, the heating water for the liquid chiller in the heating loop first undergoes heat exchange in the electrical equipment cabinet, then a second heat exchange in the battery cabinet before returning to the liquid chiller. This ensures that the water exchanged after effectively heating the power-type electrical components in the electrical equipment cabinet can further effectively heat the battery cells in the battery cabinet, ensuring the normal operation of the entire photovoltaic-storage system. Every sub-component participates in the control of the entire thermal management process, effectively reducing the overall energy consumption of the system and improving the utilization rate of the water cooling system.

[0033] Furthermore, both the battery cabinet and the electrical equipment cabinet are equipped with temperature sensors;

[0034] The temperature sensor is connected to the EMS control subsystem.

[0035] As described above, temperature sensors connected to the EMS control subsystem are installed in the battery cabinet and electrical equipment cabinet. This allows the EMS control subsystem to control whether the liquid chiller enters cooling or heating mode based on whether the temperature collected in real time by the temperature sensors in the battery cabinet and electrical equipment cabinet reaches the threshold. The subsystem also controls the opening and closing of different ports of the two three-way valves accordingly to achieve cooling or heating cycles.

[0036] Furthermore, the electrical equipment cabinet includes multiple DC-DC cabinets, one PCS cabinet, and one photovoltaic equipment cabinet, and the temperature sensor is installed in each of the multiple DC-DC cabinets and the PCS cabinet.

[0037] The connection between the liquid cooling pipeline and the electrical equipment cabinet is divided into multiple DC-DC branch pipelines and one PCS branch pipeline, which are respectively connected to multiple DC-DC cabinets and one PCS cabinet.

[0038] Furthermore, a flow valve is installed at each of the aforementioned DC-DC branch lines;

[0039] The flow valve is connected to the EMS control subsystem.

[0040] As described above, the electrical equipment cabinet includes multiple DC-DC converter cabinets, one PCS cabinet, and one photovoltaic equipment cabinet, thereby improving the overall power and performance of the photovoltaic-storage system. To ensure effective heat dissipation and heating for all DC-DC converter cabinets, each DC-DC converter cabinet and each PCS cabinet has its liquid cooling piping branched into multiple DC-DC converter branch lines and one PCS branch line. Temperature sensors are installed in each DC-DC converter cabinet, and flow valves connected to the EMS control subsystem are installed at each DC-DC converter branch line. The EMS control subsystem can then control the opening of the flow valves based on whether the temperature collected by the temperature sensors in each DC-DC converter cabinet reaches a threshold, thus controlling the flow rate of cooling or heating water entering the DC-DC converter cabinet to regulate the heat dissipation and heating effect, making the system more intelligent. Furthermore, since the photovoltaic equipment cabinet itself generates photovoltaic power, its temperature does not affect the performance of the photovoltaic modules, therefore liquid cooling is not required.

[0041] Furthermore, there are multiple battery cabinets, which are managed uniformly through the BMS battery management subsystem, and the BMS battery management subsystem is connected to the EMS control subsystem.

[0042] Both the battery cabinet and the electrical equipment cabinet are equipped with liquid cooling pipes.

[0043] As described above, the battery cabinets are also multiple and managed uniformly by the BMS battery management subsystem. While improving the overall energy storage capacity of the photovoltaic energy storage system, the BMS battery management subsystem collects the temperatures collected by the temperature acquisition devices of each battery cabinet and sends the highest or lowest temperatures to the EMS control subsystem. Thus, the EMS control subsystem can directly control the working mode of the liquid chiller and the opening and closing of different valve ports of the three-way valve to carry out cooling or heating cycles based on whether the highest or lowest battery cabinet temperature has reached the threshold, effectively reducing system energy consumption. In addition, uniform liquid cooling pipes are laid in both the battery cabinets and electrical cabinets to ensure uniform cooling and heating of the cooling water or heating water in the liquid cooling pipes within the battery cabinets and electrical cabinets, ensuring the cooling and heating effects of the liquid chiller.

[0044] Please refer to Figure 5 and Figure 6 A thermal management method for a liquid-cooled optical energy storage and charging system, employing the aforementioned liquid-cooled optical energy storage and charging system, includes the following steps:

[0045] S0. Define the valve port of the first three-way valve connected to the outlet of the liquid chiller as A, the valve port connected to the electrical equipment cabinet as B, and the valve port connected to the battery cabinet as C. Define the valve port of the second three-way valve connected to the return water port of the liquid chiller as A, the valve port connected to the electrical equipment cabinet as B, and the valve port connected to the battery cabinet as C.

[0046] S1. Determine the system operating mode. If the system operating mode is cooling mode, proceed to step S2. If the system operating mode is heating mode, proceed to step S3.

[0047] S2, the EMS control subsystem controls the opening of ports A and C of the first three-way valve and the closing of port B, and controls the opening of ports A and B of the second three-way valve and the closing of port C. Then, the liquid chiller is started to send the cooled water out from the outlet and through the liquid cooling pipeline, it flows into the battery cabinet through ports A and C of the first three-way valve for a first heat exchange to cool the battery cells. The cooled water after the first heat exchange flows out of the battery cabinet through the liquid cooling pipeline and into the electrical equipment cabinet for a second heat exchange to cool the electrical components. The cooled water after the second heat exchange flows out of the electrical equipment cabinet through the liquid cooling pipeline and through ports B and A of the second three-way valve to flow back into the liquid chiller through the return port for recooling, thus repeating the cooling cycle.

[0048] S3. The EMS control subsystem controls the opening of valve ports A and B and the closing of valve port C of the first three-way valve, and controls the opening of valve ports A and C and the closing of valve port B of the second three-way valve. Then, the liquid chiller is started to send the heated water out of the outlet and through the liquid cooling pipeline through the first three-way valve through the first three-way valve through the first two three-way valves into the electrical equipment cabinet for a first cooling exchange to heat the electrical components. The heated water after the first cooling exchange flows out of the electrical equipment cabinet through the liquid cooling pipeline and into the battery cabinet for a second cooling exchange to heat the battery cells. The heated water after the second cooling exchange flows out of the battery cabinet through the liquid cooling pipeline and through the second three-way valve through the second three-way valve through the return water port back into the liquid chiller for reheating, thus replicating the heat cycle.

[0049] As can be seen from the above description, the beneficial effects of the present invention are as follows: Based on the same technical concept, using the above-mentioned liquid-cooled photovoltaic energy storage and charging system, a thermal management method for the liquid-cooled photovoltaic energy storage and charging system is provided. This method replaces the traditional thermal management scheme that only uses liquid cooling for the battery system and air cooling for other power-type electrical components with a thermal management scheme that uniformly uses a liquid chiller for both cooling and heating of the battery cabinet and electrical equipment cabinet in the entire photovoltaic energy storage system. Within the entire system, the liquid chiller, battery cabinet, and electrical equipment cabinet are connected through liquid cooling pipelines and two three-way valves to form different cooling and heating loops. The two three-way valves are controlled by the EMS control subsystem. The opening and closing of different valve ports in the refrigeration cycle ensures that the cooling water from the liquid chiller first undergoes heat exchange in the battery cabinet, then a second heat exchange in the electrical equipment cabinet before returning to the liquid chiller. This ensures that the water exchanged after effectively cooling the battery cells in the battery cabinet can further effectively cool the high-temperature resistant electrical components in the electrical equipment cabinet. Similarly, in the heating cycle, the heating water from the liquid chiller first undergoes heat exchange in the electrical equipment cabinet, then a second heat exchange in the battery cabinet before returning to the liquid chiller. This ensures that the water exchanged after effectively heating the power-type electrical components in the electrical equipment cabinet can further effectively heat the battery cells in the battery cabinet, ensuring the normal operation of the entire photovoltaic-storage system. Every sub-component participates in the control of the entire thermal management process, effectively reducing the overall system energy consumption and improving the utilization rate of the water cooling system.

[0050] Furthermore, both the battery cabinet and the electrical equipment cabinet are equipped with temperature sensors that are connected to the EMS control subsystem.

[0051] Step S0 further includes:

[0052] Multiple battery cabinets are defined to be uniformly managed by the BMS battery management subsystem. The BMS battery management subsystem is connected to the EMS control subsystem and is used to send the highest or lowest cell temperature collected by the temperature sensors in the multiple battery cabinets to the EMS control subsystem.

[0053] Step S1 specifically involves:

[0054] S11. After the system is powered on, the EMS control subsystem acquires the cell temperature collected by the temperature sensor in the battery cabinet in real time.

[0055] S12. If the highest cell temperature Tmax is obtained and is greater than or equal to the first temperature threshold, the EMS control subsystem controls the liquid cooler to start the cooling mode and proceeds to step S2.

[0056] If the lowest cell temperature Tmin is obtained and is less than or equal to the second temperature threshold, the EMS control subsystem controls the liquid chiller to start the heating mode and proceeds to step S3, where the first temperature threshold is greater than the second temperature threshold.

[0057] As described above, temperature sensors connected to the EMS control subsystem are installed in the battery cabinet and electrical equipment cabinet. This allows the EMS control subsystem to determine whether the liquid chiller enters cooling or heating mode based on real-time temperature readings from these sensors. It also controls the opening and closing of different ports on the two three-way valves to achieve either cooling or heating cycles. Furthermore, multiple battery cabinets are managed uniformly by the BMS battery management subsystem. This improves the overall energy storage capacity of the photovoltaic-storage system. The BMS battery management subsystem collects temperatures from the temperature sensors in each battery cabinet and sends the highest or lowest temperatures to the EMS control subsystem. The EMS control subsystem can then directly control the liquid chiller's operating mode and the opening and closing of the three-way valves based on whether the highest or lowest cell temperature reaches the threshold, effectively reducing system energy consumption.

[0058] Furthermore, step S2 also includes:

[0059] When the EMS control subsystem obtains that the highest cell temperature Tmax is less than or equal to the third temperature threshold, it controls the liquid chiller to stop the cooling mode.

[0060] Step S3 further includes:

[0061] When the EMS control subsystem obtains that the lowest cell temperature Tmin is greater than the fourth temperature threshold, it controls the liquid chiller to stop the heating mode, where the third temperature threshold is greater than the fourth temperature threshold.

[0062] As described above, when the lowest or highest cell temperature collected by the temperature sensors in each battery cabinet reaches the corresponding temperature threshold that does not require cooling or heating, the liquid chiller is stopped in time to further reduce system energy consumption.

[0063] Furthermore, step S0 also includes:

[0064] The multiple DC-DC cabinets, one PCS cabinet, and one photovoltaic equipment cabinet within the battery cabinet are respectively connected to the liquid cooling pipeline through multiple DC-DC branch pipes and one PCS branch pipe. A temperature sensor is installed in each DC-DC cabinet, and a flow valve is installed at each DC-DC branch pipe.

[0065] Furthermore, in step S2, the cooling water after the first heat exchange flows out of the battery cabinet through the liquid cooling pipeline and is sent into the electrical equipment cabinet for a second heat exchange to cool the electrical components. Specifically:

[0066] The EMS control subsystem acquires the cabinet temperature T collected by multiple temperature sensors inside the DC-DC cabinet in real time. If there is a DC-DC cabinet with T > the fifth temperature threshold, the system controls the flow valve in the corresponding DC-DC branch pipe to be fully open and the flow valve in other DC-DC branch pipes to be half open. Then, the cooling water after the first heat exchange flows out of the battery cabinet through the liquid cooling pipe and flows into multiple DC-DC cabinets and one PCS cabinet through multiple DC-DC branch pipes and one PCS branch pipe for secondary heat exchange.

[0067] As described above, the electrical equipment cabinet includes multiple DC-DC converter cabinets, one PCS cabinet, and one photovoltaic equipment cabinet, thereby improving the overall power and performance of the photovoltaic-storage system. To ensure effective heat dissipation and heating for all DC-DC converter cabinets, each DC-DC converter cabinet and each PCS cabinet has its liquid cooling piping branched into multiple DC-DC converter branch lines and one PCS branch line. Temperature sensors are installed in each DC-DC converter cabinet, and flow valves connected to the EMS control subsystem are installed at each DC-DC converter branch line. The EMS control subsystem can then control the opening of the flow valves based on whether the temperature collected by the temperature sensors in each DC-DC converter cabinet reaches a threshold, thus controlling the flow rate of cooling or heating water entering the DC-DC converter cabinet to regulate the heat dissipation and heating effect, making the system more intelligent. Furthermore, since the photovoltaic equipment cabinet itself generates photovoltaic power, its temperature does not affect the performance of the photovoltaic modules, therefore liquid cooling is not required.

[0068] This invention provides a liquid-cooled photovoltaic energy storage and charging system and its thermal management method, applicable to scenarios where the thermal management of the photovoltaic energy storage and charging system involves unified cooling or heating. The following detailed description is provided in conjunction with embodiments.

[0069] Please refer to Figures 1 to 4 Embodiment 1 of the present invention is as follows:

[0070] A liquid-cooled optical energy storage and charging system, such as Figure 1 As shown, it includes a battery cabinet 1, an electrical equipment cabinet 2, a liquid cooler 3, a first three-way valve 4, a second three-way valve 5, liquid cooling pipelines, and an EMS control subsystem.

[0071] The liquid cooler 3 includes an outlet and a return outlet, wherein the outlet, the first three-way valve 4, the battery cabinet 1, the electrical equipment cabinet 2, the second three-way valve 5, and the return outlet are sequentially connected by liquid cooling pipelines to form a system as shown in the figure. Figure 3 The refrigeration cycle circuit shown in the diagram consists of a water outlet, a first three-way valve 4, an electrical equipment cabinet 2, a battery cabinet 1, a second three-way valve 5, and a water return outlet, which are sequentially connected by liquid cooling pipes to form a circuit as shown in the diagram. Figure 4 The heating cycle circuit shown; and in this embodiment, as Figure 2As shown, it also includes an EMS control subsystem, in which the first three-way valve 4 and the second three-way valve 5 are both electric three-way valves, and are connected to the EMS control subsystem via an IO module for opening and closing different valve ports under the control of the EMS control subsystem.

[0072] In addition, in this embodiment, the liquid chiller 3 is also connected to the EMS control subsystem, and the liquid chiller 3 is an integrated cooling and heating machine that can both cool and heat, and can select the working mode of cooling or heating under the control of the EMS control subsystem.

[0073] In this embodiment, the traditional thermal management scheme that uses liquid cooling only for the battery system and air cooling for other power-type electrical components is replaced with a thermal management scheme that uses a liquid chiller 3 for both cooling and heating of the battery cabinet 1 and electrical equipment cabinet 2 in the entire photovoltaic-storage system. Within the entire system, liquid cooling pipelines and two three-way valves connect the liquid chiller 3, battery cabinet 1, and electrical equipment cabinet 2 to form different cooling and heating loops. The EMS control subsystem controls the opening and closing of different ports of the two three-way valves to achieve the cooling water of the liquid chiller 3 in the cooling loop first passing through the electric... After the battery cabinet 1 undergoes a primary heat exchange, it then undergoes a secondary heat exchange in the electrical equipment cabinet 2 before returning to the liquid chiller 3. This ensures that the hot water from the battery cells in the battery cabinet 1, after effective cooling, can further effectively cool the high-temperature resistant electrical components in the electrical equipment cabinet 2. Similarly, the heating water in the liquid chiller 3 in the heating loop first undergoes a primary cooling in the electrical equipment cabinet 2, then a secondary cooling in the battery cabinet 1 before returning to the liquid chiller 3. This ensures that the cooling water from the power-type electrical components in the electrical equipment cabinet 2, after effective heating, can further effectively heat the battery cells in the battery cabinet 1, ensuring the normal operation of the entire photovoltaic-storage system. Every sub-component participates in the control of the entire thermal management process, effectively reducing the overall system energy consumption and improving the utilization rate of the water cooling system.

[0074] Please refer to Figure 1 and Figure 2 Embodiment two of the present invention is as follows:

[0075] A liquid-cooled photovoltaic energy storage and charging system, based on the above embodiment one, wherein temperature sensors are installed in both the battery cabinet 1 and the electrical equipment cabinet 2, and as shown in the figure... Figure 2 As shown, the temperature sensor is also connected to the EMS control subsystem.

[0076] In this embodiment, temperature sensors connected to the EMS control subsystem are installed in the battery cabinet 1 and the electrical equipment cabinet 2. The EMS control subsystem can control the liquid chiller 3 to enter either cooling or heating mode based on whether the temperature collected in real time by the temperature sensors in the battery cabinet 1 and the electrical equipment cabinet 2 reaches the threshold. The subsystem can also control the opening and closing of different ports of the two three-way valves to achieve either cooling or heating cycle.

[0077] In this embodiment, such as Figure 1 As shown, there are multiple battery cabinets 1, which are managed uniformly through a BMS battery management subsystem. The BMS battery management subsystem is connected to the EMS control subsystem, i.e. Figure 2 As shown.

[0078] That is, there are multiple battery cabinets 1, which are managed uniformly by the BMS battery management subsystem. While improving the overall energy storage capacity of the photovoltaic energy storage system, the BMS battery management subsystem collects the temperature collected by the temperature acquisition device of each battery cabinet 1 and sends the highest or lowest temperature to the EMS control subsystem. Thus, the EMS control subsystem can directly control the working mode of the liquid chiller 3 and the opening and closing of different valve ports of the three-way valve according to whether the highest or lowest temperature of the battery cabinet 1 reaches the threshold to carry out the cooling cycle or heating cycle, effectively reducing the system energy consumption.

[0079] In addition, in this embodiment, liquid cooling pipes are evenly laid in both the battery cabinet 1 and the electrical equipment cabinet 2, which can facilitate the uniform cooling and heating of the cooling water or heating water in the liquid cooling pipes in the battery cabinet 1 and the electrical cabinet, ensuring the cooling and heating effect of the liquid chiller 3.

[0080] It is worth noting that in one liquid-cooled inertial charging system of this embodiment, humidity sensors connected to the EMS control subsystem can also be installed in the battery cabinet 1 and electrical equipment cabinet 2, forming a temperature and humidity acquisition subsystem together with the temperature sensor, i.e., as shown in the example. Figure 2 As shown, in order to further improve the performance of the photovoltaic energy storage and charging system, the selection of cooling or heating cycle is achieved by comprehensively considering the temperature and humidity inside the battery cabinet 1 and the electrical equipment cabinet 2.

[0081] Please refer to Figures 1 to 4 Embodiment 3 of the present invention is as follows:

[0082] A liquid-cooled optical energy storage and charging system, based on the above-described embodiment two, wherein in this embodiment, as follows: Figure 1 As shown, the electrical equipment cabinet 2 includes multiple DC-DC cabinets 21, one PCS cabinet 22, and a photovoltaic equipment cabinet not shown in the figure. In this embodiment, temperature sensors are installed in each of the multiple DC-DC cabinets 21 and the PCS cabinet 22.

[0083] The connection between the liquid cooling pipeline and the electrical equipment cabinet 2 is divided into multiple DC-DC branch pipelines and one PCS branch pipeline, which are respectively connected to multiple DC-DC cabinets 21 and one PCS cabinet 22. Each DC-DC branch pipeline is equipped with a flow valve 23, and... Figure 2 As shown, the flow valve 23 is connected to the EMS control subsystem.

[0084] In this embodiment, the electrical equipment cabinet 2 includes multiple DC-DC cabinets 21, one PCS cabinet 22, and one photovoltaic equipment cabinet, thereby improving the overall power and performance of the photovoltaic energy storage system. To ensure effective heat dissipation and heating for all DC-DC cabinets 21, each DC-DC cabinet 21 and each PCS cabinet 22 is branched with liquid cooling pipes, resulting in multiple DC-DC branch pipes and one PCS branch pipe. Each DC-DC cabinet 21 is equipped with a temperature sensor, and each DC-DC branch pipe is equipped with a flow valve 23 connected to the EMS control subsystem. The EMS control subsystem can then control the opening of the flow valve 23 based on whether the temperature collected by the temperature sensor in each DC-DC cabinet 21 reaches a threshold, thus controlling the flow rate of cooling or heating water entering the DC-DC cabinet 21 to adjust the heat dissipation and heating effect, making the system more intelligent. Furthermore, since the photovoltaic equipment cabinet itself generates photovoltaic power, its temperature does not affect the performance of the photovoltaic modules, therefore liquid cooling is unnecessary.

[0085] Based on this, combined Figure 3 and Figure 4 The cooling cycle and heating cycle of a liquid-cooled optical energy storage and charging system according to this embodiment are described as follows:

[0086] First, after the system is powered on and started, the BMS battery management subsystem acquires the cell temperature collected by the temperature sensors in each electrical cabinet in real time, and calculates the highest cell temperature Tmax and the lowest cell temperature Tmin and sends them to the EMS control subsystem.

[0087] Then, the EMS control subsystem receives the highest cell temperature Tmax and the lowest cell temperature Tmin in real time. If the highest cell temperature Tmax is greater than or equal to the first temperature threshold of 25°C, the system enters the cooling cycle; if the lowest cell temperature Tmin is less than or equal to the second temperature threshold of 15°C, the system enters the heating cycle.

[0088] The refrigeration cycle process is as follows:

[0089] First, the EMS control subsystem controls the liquid chiller 3TMS to execute the cooling mode.

[0090] Then, the liquid chiller 3TMS starts the cooling mode and works, generating cooling water. At this time, the EMS control subsystem controls the opening of valves A and C and the closing of valve B of the first three-way valve 4, and controls the opening of valves A and B and the closing of valve C of the second three-way valve 5. The cooling water in the liquid chiller 3TMS is discharged through the outlet and flows into the battery cabinet 1 through the liquid cooling pipeline via the first three-way valve 4 to perform a heat exchange on the high-temperature battery cells. The heat exchanged water then flows out through the liquid cooling pipeline and flows into the various branches of the electrical equipment cabinet 2 to perform a secondary heat exchange on the DC-DC cabinet 21 and the PCS cabinet 22.

[0091] After the final secondary heat exchange, the cooling water flows out of the electrical equipment cabinet 2 through the liquid cooling pipeline and returns to the return water port through the second three-way valve 5 to be cooled again in the liquid chiller 3TMS, thus repeating the cooling process.

[0092] During the refrigeration cycle, when the highest cell temperature Tmax received in real time by the EMS control subsystem is less than or equal to the third temperature threshold of 21°C, the liquid chiller 3TMS is controlled to stop the refrigeration cycle.

[0093] During the refrigeration cycle, the outlet temperature of the liquid chiller 3TMS is between 18 and 25°C. The temperature of the cooling water after one heat exchange in the battery cabinet 1 is about 30°C. The operating temperature of the power devices in the DC-DC cabinet 21 and PCS cabinet 22 can reach 40 to 50°C. The cooling water after one heat exchange can still achieve a good cooling effect after passing through the DC-DC cabinet 21 and PCS cabinet 22.

[0094] The heating cycle process is as follows:

[0095] First, the EMS control subsystem controls the liquid chiller 3TMS to execute the heating mode.

[0096] Then, the liquid chiller 3TMS starts heating mode and operates, generating heated water. At this time, the EMS control subsystem controls the opening of valves A and B and the closing of valve C of the first three-way valve 4, and controls the opening of valves A and C and the closing of valve B of the second three-way valve 5. The heated water in the liquid chiller 3TMS is discharged through the outlet and flows into the electrical equipment cabinet 2 through the liquid cooling pipeline via the first three-way valve 4 to perform a first cooling and heating of the power electrical components in the DC-DC cabinet 21 and PCS cabinet 22. The heated water then flows out through the liquid cooling pipeline and flows into the battery cabinet 1 to perform a second cooling of the battery cells in each battery cabinet 1.

[0097] After the second cooling cycle, the heated water flows out of the battery cabinet 1 through the liquid cooling pipeline and returns to the return water port through the second three-way valve 5 to be reheated in the liquid chiller 3TMS, thus repeating the heating process.

[0098] During the heating cycle, when the lowest cell temperature Tmin received in real time by the EMS control subsystem is greater than the fourth temperature threshold of 20°C, the liquid chiller 3TMS is controlled to stop the heating cycle.

[0099] During the heating cycle, the original target temperature of the liquid chiller 3TMS outlet was set at around 35℃. The operating temperature of the power devices in PCS cabinet 22 and DC-DC cabinet 21 can reach 40-50℃. The temperature of the heated water can be increased by about 5℃ after one cooling exchange through PCS cabinet 22 and DC-DC cabinet 21. Therefore, the target set temperature value of the liquid chiller 3TMS outlet can be reduced, thereby improving the utilization rate of the water cooling system.

[0100] In addition, each DC-DC cabinet 21 is equipped with a flow valve 23 connected to the EMS control subsystem at its DC-DC branch line. This allows the EMS control subsystem to receive the temperature data collected by the temperature sensor inside the DC-DC cabinet 21 in real time during the cooling or heating cycle, and to control the amount of water flowing into each DC-DC branch line. When the temperature T inside the DC-DC cabinet 21 is greater than the fifth temperature threshold of 40°C, the flow valve 23 corresponding to that branch line is fully opened; otherwise, the flow valve 23 corresponding to that branch line is partially opened.

[0101] Please refer to Figure 5 Embodiment four of the present invention is as follows:

[0102] A thermal management method for a liquid-cooled optical energy storage and charging system, employing a liquid-cooled optical energy storage and charging system from any of the embodiments 1 to 3 above, wherein in this embodiment, as... Figure 5 As shown, the steps include:

[0103] S0. Define the valve port of the first three-way valve connected to the outlet of the liquid chiller as A, the valve port connected to the electrical equipment cabinet as B, and the valve port connected to the battery cabinet as C. Define the valve port of the second three-way valve connected to the return water port of the liquid chiller as A, the valve port connected to the electrical equipment cabinet as B, and the valve port connected to the battery cabinet as C.

[0104] S1. Determine the system operating mode. If the system operating mode is cooling mode, proceed to step S2. If the system operating mode is heating mode, proceed to step S3.

[0105] The S2 and EMS control subsystems control the opening of ports A and C of the first three-way valve and the closing of port B, and control the opening of ports A and B of the second three-way valve and the closing of port C. Then, the liquid chiller is started to send the cooled water out of the outlet and through the liquid cooling pipeline, it flows into the battery cabinet through ports A and C of the first three-way valve for the first heat exchange to cool the battery cells. After the first heat exchange, the cooled water flows out of the battery cabinet through the liquid cooling pipeline and into the electrical equipment cabinet for the second heat exchange to cool the electrical components. After the second heat exchange, the cooled water flows out of the electrical equipment cabinet through the liquid cooling pipeline and through ports B and A of the second three-way valve to return to the liquid chiller through the return outlet for recooling, thus replicating the cooling cycle.

[0106] The S3 and EMS control subsystems control the opening of valves A and B and the closing of valve C of the first three-way valve, and control the opening of valves A and C and the closing of valve B of the second three-way valve. Then, the liquid chiller is started to send the heated water out of the outlet and through the liquid cooling pipeline, it flows into the electrical equipment cabinet through the valves A and B of the first three-way valve for the first cooling to heat the electrical components. After the first cooling, the heated water flows out of the electrical equipment cabinet through the liquid cooling pipeline and into the battery cabinet for the second cooling to heat the battery cells. After the second cooling, the heated water flows out of the battery cabinet through the liquid cooling pipeline and through the valves C and A of the second three-way valve back into the liquid chiller for reheating, thus replicating the heat cycle.

[0107] In this embodiment, based on the same technical concept, a liquid-cooled photovoltaic energy storage and charging system is adopted, providing a thermal management method for the liquid-cooled photovoltaic energy storage and charging system. This method replaces the traditional thermal management scheme that uses liquid cooling only for the battery system and air cooling for other power-type electrical components with a scheme that uses a liquid chiller for both cooling and heating of the battery cabinet and electrical equipment cabinet throughout the entire photovoltaic energy storage system. Within the entire system, liquid cooling pipelines and two three-way valves connect the liquid chiller, battery cabinet, and electrical equipment cabinet to form different cooling and heating loops. The EMS control subsystem controls different valve ports of the two three-way valves. The system controls the opening and closing of the water supply to achieve the following: In the cooling cycle, the cooling water from the liquid chiller first undergoes heat exchange in the battery cabinet, then a second heat exchange in the electrical equipment cabinet before returning to the liquid chiller. This ensures that the water exchanged after effectively cooling the battery cells in the battery cabinet can further effectively cool the high-temperature resistant electrical components in the electrical equipment cabinet. Similarly, in the heating cycle, the heating water from the liquid chiller first undergoes heat exchange in the electrical equipment cabinet, then a second heat exchange in the battery cabinet before returning to the liquid chiller. This ensures that the water exchanged after effectively heating the power-type electrical components in the electrical equipment cabinet can further effectively heat the battery cells in the battery cabinet, ensuring the normal operation of the entire photovoltaic-storage system. Every sub-component participates in the control of the entire thermal management process, effectively reducing the overall energy consumption of the system and improving the utilization rate of the water cooling system.

[0108] Please refer to Figures 3 to 6 Embodiment five of the present invention is as follows:

[0109] A thermal management method for a liquid-cooled photovoltaic energy storage and charging system, based on the above-described embodiment four, wherein in this embodiment, temperature sensors connected to the EMS control subsystem are installed in both the battery cabinet and the electrical equipment cabinet.

[0110] In this embodiment, step S0 further includes:

[0111] Multiple battery cabinets are defined to be managed uniformly by the BMS battery management subsystem. The BMS battery management subsystem is connected to the EMS control subsystem and is used to send the highest or lowest cell temperature collected by the temperature sensors in the multiple battery cabinets to the EMS control subsystem.

[0112] Then as Figure 6 As shown, step S1 specifically involves:

[0113] S11. After the system is powered on, the EMS control subsystem acquires the cell temperature collected by the temperature sensor inside the battery cabinet in real time.

[0114] S12. If the highest cell temperature Tmax is obtained and is greater than or equal to the first temperature threshold of 25°C, the EMS control subsystem controls the liquid chiller to start the cooling mode and proceeds to step S2.

[0115] If the lowest cell temperature Tmin is obtained and is less than or equal to the second temperature threshold of 15°C, the EMS control subsystem controls the liquid chiller to start the heating mode and proceeds to step S3.

[0116] In this embodiment, the first temperature threshold and the second temperature threshold can be set according to actual needs, as long as the first temperature threshold is greater than the second temperature threshold.

[0117] In this embodiment, temperature sensors connected to the EMS control subsystem are installed in the battery cabinet and electrical equipment cabinet. The EMS control subsystem can then control the liquid chiller to enter either cooling or heating mode based on whether the real-time temperature collected by the temperature sensors in the battery cabinet and electrical equipment cabinet reaches a threshold. It also controls the opening and closing of different ports of the two three-way valves accordingly to achieve cooling or heating cycles. Furthermore, multiple battery cabinets are managed uniformly by the BMS battery management subsystem. While increasing the overall energy storage capacity of the photovoltaic-energy storage system, the BMS battery management subsystem collects the temperatures collected by the temperature sensors in each battery cabinet and sends the highest or lowest temperature to the EMS control subsystem. Thus, the EMS control subsystem can directly control the operating mode of the liquid chiller and the opening and closing of different ports of the three-way valves to achieve cooling or heating cycles based on whether the highest or lowest cell temperature reaches the threshold, effectively reducing system energy consumption.

[0118] In this embodiment, for example... Figure 6 As shown, step S2 further includes:

[0119] When the EMS control subsystem obtains that the highest cell temperature Tmax is less than or equal to the third temperature threshold of 21°C, it controls the liquid chiller to stop the cooling mode.

[0120] Step S3 also includes:

[0121] When the EMS control subsystem detects that the lowest cell temperature Tmin is greater than the fourth temperature threshold of 20°C, it controls the liquid chiller to stop the heating mode. Similarly, in this embodiment, the third and fourth temperature thresholds can be set according to actual needs, as long as the third temperature threshold is greater than the fourth temperature threshold.

[0122] This means that when the lowest or highest cell temperature collected by the temperature sensors in each battery cabinet reaches the corresponding temperature threshold that does not require cooling or heating, the liquid chiller is stopped in time to further reduce system energy consumption.

[0123] Embodiment six of the present invention is as follows:

[0124] A thermal management method for a liquid-cooled optical energy storage and charging system, based on the above-described embodiment five, further includes step S0 in this embodiment:

[0125] The battery cabinet is defined to have multiple DC-DC cabinets, one PCS cabinet and one photovoltaic equipment cabinet connected to the liquid cooling pipeline through multiple DC-DC branch pipes and one PCS branch pipe. A temperature sensor is installed in each DC-DC cabinet and a flow valve is installed at each DC-DC branch pipe.

[0126] In step S2, the cooling water after the first heat exchange flows out of the battery cabinet through the liquid cooling pipeline and is sent into the electrical equipment cabinet for a second heat exchange to cool the electrical components. Specifically:

[0127] The EMS control subsystem acquires the internal temperature T from multiple DC-DC cabinet temperature sensors in real time. If any DC-DC cabinet has a T > 40°C (the fifth temperature threshold), the system controls the flow valve in the corresponding DC-DC branch to be fully open, while the flow valves in other DC-DC branch pipes are partially open. The cooling water after the first heat exchange then flows out of the battery cabinet through the liquid cooling pipeline and flows into multiple DC-DC cabinets and one PCS cabinet via multiple DC-DC branch pipes and one PCS branch pipe for secondary heat exchange. In this embodiment, the fifth temperature threshold can be set according to actual needs.

[0128] In this embodiment, the electrical equipment cabinet includes multiple DC-DC converter cabinets, one PCS cabinet, and one photovoltaic equipment cabinet, thereby improving the overall power and performance of the photovoltaic energy storage system. To ensure effective heat dissipation and heating for all DC-DC converter cabinets, each DC-DC converter cabinet and each PCS cabinet has its liquid cooling piping branched into multiple DC-DC converter branch lines and one PCS branch line. Each DC-DC converter cabinet is equipped with a temperature sensor, and each DC-DC converter branch line has a flow valve connected to the EMS control subsystem. The EMS control subsystem can then control the opening of the flow valve based on whether the temperature collected by the temperature sensor in each DC-DC converter cabinet reaches a threshold, thus controlling the flow rate of cooling or heating water entering the DC-DC converter cabinet to regulate the heat dissipation and heating effect, making the system more intelligent. Furthermore, since the photovoltaic equipment cabinet itself generates photovoltaic power, its temperature does not affect the performance of the photovoltaic modules, therefore liquid cooling is not required.

[0129] In summary, the present invention provides a liquid-cooled photovoltaic energy storage and charging system and its thermal management method. This replaces the traditional thermal management scheme that uses liquid cooling only for the battery system and air cooling for other power-type electrical components with a scheme that uses a liquid chiller for both cooling and heating of the battery cabinet and electrical equipment cabinet throughout the entire photovoltaic energy storage system. Within the system, liquid cooling pipelines and two three-way valves connect the liquid chiller, battery cabinet, and electrical equipment cabinet to form different cooling and heating loops. The EMS control subsystem controls the opening and closing of different ports of the two three-way valves to achieve the cooling cycle. In the circuit, the cooling water of the liquid chiller first undergoes heat exchange in the battery cabinet and then undergoes a second heat exchange in the electrical equipment cabinet before flowing back into the liquid chiller. This ensures that the hot water exchanged after the battery cells in the battery cabinet are effectively cooled can further effectively cool the high-temperature resistant electrical components in the electrical equipment cabinet. Similarly, in the heating circuit, the hot water of the liquid chiller first undergoes heat exchange in the electrical equipment cabinet and then undergoes a second heat exchange in the battery cabinet before flowing back into the liquid chiller. This ensures that the hot water exchanged after the power-type electrical components in the electrical equipment cabinet are effectively heated can further effectively heat the battery cells in the battery cabinet, ensuring the normal operation of the entire photovoltaic energy storage system.

[0130] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A liquid-cooled optical energy storage and charging system, characterized in that, It includes battery cabinet, electrical equipment cabinet, liquid chiller, first three-way valve, second three-way valve, liquid cooling pipeline and EMS control subsystem; The liquid cooler includes an outlet and an inlet; The water outlet, the first three-way valve, the battery cabinet, the electrical equipment cabinet, the second three-way valve, and the water return outlet are sequentially connected through the liquid cooling pipeline to form a refrigeration cycle loop; The water outlet, the first three-way valve, the electrical equipment cabinet, the battery cabinet, the second three-way valve, and the water return outlet are sequentially connected through the liquid cooling pipeline to form a heating circulation loop; The first three-way valve, the second three-way valve, and the liquid chiller are all connected to the EMS control subsystem for control, and the liquid chiller is an integrated cooling and heating unit; Temperature sensors are installed in both the battery cabinet and the electrical equipment cabinet. The temperature sensors are connected to the EMS control subsystem. The EMS control subsystem controls the working mode of the liquid chiller based on the temperature collected in real time by the temperature sensors, and controls the opening and closing of different valve ports of the first three-way valve and the second three-way valve accordingly. The working modes include cooling mode and heating mode.

2. The liquid-cooled optical energy storage and charging system according to claim 1, characterized in that, The electrical equipment cabinet includes multiple DC-DC cabinets, one PCS cabinet, and one photovoltaic equipment cabinet, and the temperature sensor is installed in each of the multiple DC-DC cabinets and the PCS cabinet. The connection between the liquid cooling pipeline and the electrical equipment cabinet is divided into multiple DC-DC branch pipelines and one PCS branch pipeline, which are respectively connected to multiple DC-DC cabinets and one PCS cabinet.

3. The liquid-cooled optical energy storage and charging system according to claim 2, characterized in that, A flow valve is installed at each of the aforementioned DC-DC branch lines; The flow valve is connected to the EMS control subsystem.

4. The liquid-cooled optical energy storage and charging system according to claim 1, characterized in that, There are multiple battery cabinets, which are managed uniformly through the BMS battery management subsystem. The BMS battery management subsystem is connected to the EMS control subsystem. Both the battery cabinet and the electrical equipment cabinet are equipped with liquid cooling pipes.

5. A thermal management method for a liquid-cooled photovoltaic energy storage and charging system, characterized in that, The liquid-cooled optical energy storage and charging system according to any one of claims 1 to 4 includes the following steps: S0. Define the valve port of the first three-way valve connected to the outlet of the liquid chiller as A, the valve port connected to the electrical equipment cabinet as B, and the valve port connected to the battery cabinet as C. Define the valve port of the second three-way valve connected to the return water port of the liquid chiller as A, the valve port connected to the electrical equipment cabinet as B, and the valve port connected to the battery cabinet as C. S1. Determine the system operating mode. If the system operating mode is cooling mode, proceed to step S2. If the system operating mode is heating mode, proceed to step S3. S2, the EMS control subsystem controls the opening of ports A and C of the first three-way valve and the closing of port B, and controls the opening of ports A and B of the second three-way valve and the closing of port C. Then, the liquid chiller is started to send the cooled water out from the outlet and through the liquid cooling pipeline, it flows into the battery cabinet through ports A and C of the first three-way valve for a first heat exchange to cool the battery cells. The cooled water after the first heat exchange flows out of the battery cabinet through the liquid cooling pipeline and into the electrical equipment cabinet for a second heat exchange to cool the electrical components. The cooled water after the second heat exchange flows out of the electrical equipment cabinet through the liquid cooling pipeline and through ports B and A of the second three-way valve to flow back into the liquid chiller through the return port for recooling, thus repeating the cooling cycle. S3. The EMS control subsystem controls the opening of valve ports A and B and the closing of valve port C of the first three-way valve, and controls the opening of valve ports A and C and the closing of valve port B of the second three-way valve. Then, the liquid chiller is started to send the heated water out of the outlet and through the liquid cooling pipeline through the first three-way valve through the first three-way valve through the first two three-way valves into the electrical equipment cabinet for a first cooling exchange to cool the electrical components. The heated water after the first cooling exchange flows out of the electrical equipment cabinet through the liquid cooling pipeline and into the battery cabinet for a second cooling exchange to heat the battery cells. The heated water after the second cooling exchange flows out of the battery cabinet through the liquid cooling pipeline and through the second three-way valve through the second three-way valve through the return water port back into the liquid chiller for reheating, thus replicating the heat cycle. Step S0 further includes: Multiple battery cabinets are defined to be uniformly managed by the BMS battery management subsystem. The BMS battery management subsystem is connected to the EMS control subsystem and is used to send the highest or lowest cell temperature collected by the temperature sensors in the multiple battery cabinets to the EMS control subsystem. Step S1 specifically involves: S11. After the system is powered on, the EMS control subsystem acquires the cell temperature collected by the temperature sensor in the battery cabinet in real time. S12. If the highest cell temperature Tmax is obtained and is greater than or equal to the first temperature threshold, the EMS control subsystem controls the liquid cooler to start the cooling mode and proceeds to step S2. If the lowest cell temperature Tmin is obtained and is less than or equal to the second temperature threshold, the EMS control subsystem controls the liquid chiller to start the heating mode and proceeds to step S3, where the first temperature threshold is greater than the second temperature threshold.

6. The thermal management method for a liquid-cooled optical energy storage and charging system according to claim 5, characterized in that, Step S2 further includes: When the EMS control subsystem obtains that the highest cell temperature Tmax is less than or equal to the third temperature threshold, it controls the liquid chiller to stop the cooling mode. Step S3 further includes: When the EMS control subsystem obtains that the lowest cell temperature Tmin is greater than the fourth temperature threshold, it controls the liquid chiller to stop the heating mode, where the third temperature threshold is greater than the fourth temperature threshold.

7. The thermal management method for a liquid-cooled photovoltaic energy storage and charging system according to claim 5, characterized in that, Step S0 further includes: The multiple DC-DC cabinets, one PCS cabinet, and one photovoltaic equipment cabinet within the electrical equipment cabinet are respectively connected to the liquid cooling pipeline through multiple DC-DC branch pipes and one PCS branch pipe. A temperature sensor is installed in each DC-DC cabinet, and a flow valve is installed at each DC-DC branch pipe.

8. The thermal management method for a liquid-cooled photovoltaic energy storage and charging system according to claim 7, characterized in that, In step S2, the cooling water after the first heat exchange flows out of the battery cabinet through the liquid cooling pipeline and is sent into the electrical equipment cabinet for a second heat exchange to cool the electrical components. Specifically: The EMS control subsystem acquires the cabinet temperature T collected by multiple temperature sensors inside the DC-DC cabinet in real time. If there is a DC-DC cabinet with T > the fifth temperature threshold, the system controls the flow valve in the corresponding DC-DC branch pipe to be fully open and the flow valve in other DC-DC branch pipes to be half open. Then, the cooling water after the first heat exchange flows out of the battery cabinet through the liquid cooling pipe and flows into multiple DC-DC cabinets and one PCS cabinet through multiple DC-DC branch pipes and one PCS branch pipe for secondary heat exchange.

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