Energy storage system and thermal management method thereof

Abstract

The invention relates to the technical field of energy, in particular to an energy storage system and a heat management method thereof. The energy storage system comprises a battery unit, a power conversion unit and a radiator, the battery unit is electrically connected with the power conversion unit, and the power conversion unit is used for performing power conversion on electric energy output by the battery unit and then outputting the electric energy to a load or a power grid, or is used for performing power conversion on electric energy input by the power grid and then providing the electric energy to the battery unit; the radiator comprises a first liquid cooling channel and a second liquid cooling channel which are mutually independent; the power conversion unit comprises a plurality of power modules attached to the radiator; when the temperature of each power module is smaller than a temperature threshold value, the first liquid cooling channel is used for introducing a cooling working medium, and when the temperature of at least one power module is larger than or equal to the temperature threshold value, the first liquid cooling channel and the second liquid cooling channel are both used for introducing the cooling working medium. The energy storage system has high overload capacity, and can prevent the power device of the power conversion unit from losing efficacy or being damaged when the system is overloaded.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy, in particular to an energy storage system and a thermal management method thereof. BACKGROUND

[0002] With the development of science and technology, energy storage systems are applied in scenarios such as household energy storage, industrial energy storage, data centers, power stations and vehicle charging, for storing and releasing electric energy. The heat generated by the battery and the power conversion unit in the energy storage system will affect the performance of the energy storage system. In the prior art, liquid cooling technology has become the mainstream design scheme for heat dissipation of energy storage systems due to its high heat transfer rate and low failure rate.

[0003] In some application scenarios, the power conversion unit of the energy storage system has an overload phenomenon, and there is a higher requirement for the overload capacity of the power conversion unit, which also poses new challenges for the cooling of the power conversion unit. SUMMARY

[0004] The present application provides an energy storage system and a thermal management method thereof. The heat dissipation unit of the energy storage system can change different heat dissipation modes according to the working condition of the energy storage system, so as to improve the overload capacity of the energy storage system.

[0005] In a first aspect, the present application provides an energy storage system, which comprises a battery unit, a power conversion unit and a radiator; the battery unit is electrically connected with the power conversion unit, the power conversion unit is used for converting the electric energy output by the battery unit and outputting the converted electric energy to a load or a power grid, or is used for converting the electric energy input by the power grid and providing the converted electric energy to the battery unit; the radiator comprises a first liquid cooling channel and a second liquid cooling channel which are independent of each other; the power conversion unit comprises a plurality of power modules which are arranged in abutment with the radiator; when the temperature of each power module is less than a temperature threshold, the first liquid cooling channel is used for introducing a cooling medium, and when the temperature of at least one power module is greater than or equal to the temperature threshold, the first liquid cooling channel and the second liquid cooling channel are both used for introducing the cooling medium; or, when the temperature of each power module is less than the temperature threshold, the first liquid cooling channel is used for flowing the cooling medium, and when the temperature of at least one power module is greater than or equal to the temperature threshold, the second liquid cooling channel is used for introducing the cooling medium, and the temperature of the cooling medium in the second liquid cooling channel is lower than the temperature of the cooling medium in the first liquid cooling channel.

[0006] The radiator of the above-mentioned energy storage system adopts a double-liquid cooling channel design, and the working states of the two liquid cooling channels can be adjusted according to different working modes of the energy storage system. When the energy storage system is in a normal working condition, the liquid cooling of the power conversion unit is satisfied with a lower power consumption, and when the energy storage system is in an overload working condition, the liquid cooling of the power conversion unit is rapidly performed with a higher heat dissipation efficiency, so as to prevent the power devices of the power conversion unit from over-temperature failure or damage.

[0007] In a possible implementation, the energy storage system further comprises two liquid cooling pipes and two heat exchangers, the first liquid cooling channel and one of the heat exchangers form a first liquid cooling loop for circulating the cooling medium through the first liquid cooling pipe in series, and the second liquid cooling channel and the other heat exchanger form a second liquid cooling loop for circulating the cooling medium through the second liquid cooling pipe in series; each heat exchanger is configured to exchange heat between the cooling medium in the liquid cooling pipe and the external environment, and the heat exchanger can cool the cooling medium through heat exchange with the external environment. The type and position of the heat exchanger can be designed according to actual requirements.

[0008] In a possible implementation, the power conversion unit comprises a controller. The first liquid cooling loop comprises a first control valve arranged on the liquid cooling pipe, and the first control valve is configured to adjust the flow rate of the cooling medium in the first liquid cooling pipe. The second liquid cooling loop comprises a second control valve arranged on the liquid cooling pipe, and the second control valve is configured to adjust the flow rate of the cooling medium in the second liquid cooling pipe. The controller is electrically connected to the first control valve and the second control valve respectively. The controller is specifically configured to: when the temperature of each power module is less than a temperature threshold, the controller controls the first control valve to be opened and the second control valve to be closed to allow the first liquid cooling channel to pass through the cooling medium; and when the temperature of at least one power module is greater than or equal to the temperature threshold, the controller controls the first control valve and the second control valve to be opened to allow the first liquid cooling channel and the second liquid cooling channel to pass through the cooling medium. Alternatively, the controller is specifically configured to: when the temperature of each power module is less than a temperature threshold, the controller controls the first control valve to be opened and the second control valve to be closed to allow the first liquid cooling channel to pass through the cooling medium; and when the temperature of at least one power module is greater than or equal to the temperature threshold, the controller controls the second control valve to be opened and the first control valve to be closed to allow the second liquid cooling channel to pass through the cooling medium, and the temperature of the cooling medium in the second liquid cooling channel is lower than the temperature of the cooling medium in the first liquid cooling channel. The controller controls the operation mode of the heat dissipation unit, and the intelligent operation of the heat dissipation unit can be improved.

[0009] In a possible implementation, the power conversion unit comprises a direct-current / alternating-current converter, and the controller is further configured to control the direct-current / alternating-current converter to convert direct current output by the battery unit into alternating current to output to the load or the power grid, or convert alternating current input by the power grid into direct current to supply to the battery unit. At this time, the power modules included in the direct-current / alternating-current converter can be integrated in a box body, and the heat sink can liquid-cool and dissipate heat for the power modules included in the direct-current / alternating-current converter.

[0010] In a possible implementation, the power conversion unit includes a DC / DC converter and a DC / AC converter, and the controller is further configured to control the DC / DC converter to perform power conversion, so that DC power output by the battery unit is output to the DC / AC converter or DC power input to the DC / AC converter is input to the battery unit; and the controller is further configured to control the DC / AC converter to convert DC power output by the DC / DC converter into AC power and output the AC power to the load or the power grid, or convert AC power input from the power grid into DC power and supply the DC power to the DC / DC converter. In this case, the power modules included in the DC / AC converter and the DC / DC converter can be integrated in one box, and the heat sink can be used to liquid-cool the power modules included in the DC / AC converter and the DC / DC converter.

[0011] In a possible implementation, the energy storage system includes a monitoring module, the monitoring module includes a voltage monitoring device, a current monitoring device, and a first temperature sensor, which are electrically connected to the controller respectively; the voltage monitoring device is configured to monitor the voltage at the input end and the output end of the DC / AC converter, the current monitoring device is configured to monitor the current at the output end of the DC / AC converter, and the first temperature sensor is configured to monitor the temperature of the heat sink; and the controller is configured to calculate the temperature of the power modules of the power conversion unit according to the voltage at the input end and the output end of the DC / AC converter, the current at the output end of the DC / AC converter, and the temperature of the heat sink. The monitoring module can intelligently monitor the state parameters in the working process of the energy storage system, thereby providing a reference for the control action of the controller.

[0012] Alternatively, the monitoring module can further include a second temperature sensor configured to monitor the temperature of each power module in the power conversion unit, so that the temperature of each power module in the power conversion unit can be directly obtained.

[0013] In a possible implementation, a circulating pump is connected in series to the liquid cooling pipeline of each liquid cooling loop, and the circulating pump is configured to drive the cooling medium in the liquid cooling loop to flow. The control valve and the circulating pump are not limited in position, and the flow rate and flow volume of the cooling medium in the liquid cooling loop can be adjusted by the control valve and the circulating pump.

[0014] In a possible implementation, the energy storage system includes a cabinet, and the battery unit, the power conversion unit, and the heat sink are accommodated in the cabinet. The cabinet can provide protection for the battery unit, the power conversion unit, and the heat sink.

[0015] Possibly, when the energy storage system includes two heat exchangers connected to the two liquid cooling channels of the heat sink respectively, each liquid cooling channel and a heat exchanger connected thereto form a liquid cooling loop. An opening that penetrates the side wall of the cabinet is formed in the side wall of the cabinet, and the heat exchanger can be arranged at the opening, so that the heat exchanger can exchange heat with the external environment through the opening, thereby improving the heat exchange effect.

[0016] In a second aspect, the present application provides a thermal management method of an energy storage system, the energy storage system comprising a battery unit, a power conversion unit and a heat dissipation unit, the battery unit being electrically connected with the power conversion unit; the heat dissipation unit comprising a first liquid cooling channel and a second liquid cooling channel which are independent of each other; the power conversion unit comprising a plurality of power modules fixed on the heat dissipation unit, and a projection of each power module on the heat dissipation unit at least partially overlaps with a path of each liquid cooling channel; the thermal management method comprising:

[0017] obtaining working condition information of the energy storage system and obtaining a temperature of each power module in the power conversion unit according to the working condition information;

[0018] adjusting a flow rate of a cooling medium in the first liquid cooling channel and a flow rate of a cooling medium in the second liquid cooling channel according to the temperatures of the plurality of power modules.

[0019] The thermal management method of the energy storage system can dynamically regulate and control the heat dissipation of the power conversion unit, so as to ensure the normal operation of the energy storage system and keep a high overload capacity of the energy storage system to cope with short-time overload or power grid fluctuation. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A structural schematic diagram of an energy storage system provided by an embodiment of the present application;

[0021] Figure 2 A structural schematic diagram of a heat dissipation unit and a power conversion unit of an energy storage system provided by an embodiment of the present application;

[0022] Figure 3 A structural schematic diagram of a heat dissipation unit and a power conversion unit of an energy storage system provided by an embodiment of the present application;

[0023] Figure 4a A working principle schematic diagram of a heat dissipation unit of an energy storage system provided by an embodiment of the present application operating in a first heat dissipation mode;

[0024] Figure 4b A working principle schematic diagram of a heat dissipation unit of an energy storage system provided by an embodiment of the present application operating in a first heat dissipation mode;

[0025] Figure 5 A schematic diagram of a heat dissipation unit of an energy storage system provided by an embodiment of the present application operating in a second heat dissipation mode;

[0026] Figure 6 A structural schematic diagram of an energy storage system provided by an embodiment of the present application;

[0027] Figure 7a A structural schematic diagram of an energy storage system provided by an embodiment of the present application;

[0028] Figure 7b A structural schematic diagram of a power storage system provided for an embodiment of the present application;

[0029] Figure 8 A structural schematic diagram of a power storage system provided for an embodiment of the present application;

[0030] Figure 9a A structural schematic diagram of a controller and a monitoring module of a power storage system provided for an embodiment of the present application;

[0031] Figure 9b A structural schematic diagram of a controller and a monitoring module of a power storage system provided for an embodiment of the present application;

[0032] Figure 9c A heat dissipation mode control architecture schematic diagram of a power storage system provided for an embodiment of the present application;

[0033] Figure 10 A structural schematic diagram of a power supply system provided for an embodiment of the present application;

[0034] Figure 11 A flow schematic diagram of a thermal management method of a power storage system provided for an embodiment of the present application;

[0035] Figure 12 A flow schematic diagram of a thermal management method of a power storage system provided for an embodiment of the present application;

[0036] Figure 13 A flow schematic diagram of a thermal management method of a power storage system provided for an embodiment of the present application;

[0037] Figure 14 A logic flow schematic diagram of a thermal management method of a power storage system provided for an embodiment of the present application.

[0038] Reference signs: 10-power storage system; 1-battery unit; 2-power conversion unit; 21-power module; 3-heat dissipation unit; 31-radiator; 311-first liquid cooling channel; 312-second liquid cooling channel; 32a-first heat exchanger; 32b-second heat exchanger; 33a-first control valve; 33b-second control valve; 34a-first circulating pump; 34b-second circulating pump; 4-controller; 5-monitoring module; 51-first temperature sensor; 52-voltage monitoring device; 53-current monitoring device; 54-second temperature sensor. DETAILED DESCRIPTION

[0039] The power storage system can be configured with a liquid cooling heat dissipation system to dissipate heat for the battery and the power conversion unit, so that the power storage system can operate at a higher efficiency. In some possible scenarios, the power storage system is overloaded, and the power storage system needs to have a higher overload support capability.

[0040] Based on this, the embodiment of the present application provides a kind of energy storage system and its thermal management method, the configuration two cooling circuits of the energy storage system are carried out to power conversion unit heat dissipation, different heat dissipation modes can be selected according to different working conditions, power conversion unit can be cooled in time when power conversion unit overload, power conversion unit is cooled, and then the overload support capability of power conversion unit is improved.

[0041] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings.

[0042] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to be limiting to the present application. As used in the specification and the appended claims of the present application, the singular forms "a," "an," and "the" are intended to include both the singular and plural forms, e.g., "a" or "one" means "one or more" unless the context clearly indicates otherwise.

[0043] In the present specification, the phrase "one embodiment" or "some embodiments" etc. means that the specific features, structures or characteristics described in connection with the embodiment are included in one or more embodiments of the present application. Therefore, the phrases "in one embodiment", "in some embodiments", "in other some embodiments", "in further some embodiments" etc. appearing in different places in the present specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "comprise", "include", "have" and their conjugates mean "including but not limited to", unless otherwise specifically emphasized. In the embodiments of the present application, "connected" means electrically connected, and the connection between two electrical elements can be direct or indirect connection between the two electrical elements. For example, A is connected with B, which can be direct connection between A and B, or indirect connection between A and B through one or more other electrical elements, for example, A is connected with B, which can be direct connection between A and C, direct connection between C and B, and connection between A and B through C.

[0044] Figure 1A structural diagram of an energy storage system 10 is provided in the embodiments of the present application. The energy storage system 10 can be applied to scenarios such as household energy storage, industrial energy storage, data centers, power stations, and vehicle charging, and is used for storing and releasing electric energy. Exemplarily, the energy storage system 10 provided by the embodiments of the present application includes a battery unit 1 and a power conversion unit 2. The battery unit 1, as an energy storage unit of the energy storage system 10, can be used to store electric energy. The battery unit 1 can include a plurality of energy storage batteries, each of which is electrically connected to the power conversion unit 2. The power conversion unit 2 can be specifically used to convert and output the electric energy output by the battery unit 1 to a load or a power grid, and can also be used to convert and provide the electric energy input by the power grid to the battery unit 1. The power conversion unit 2 can be integrated in a container of the battery unit 1 or can be independently arranged relative to the battery unit 1. For the battery unit 1 of the energy storage system 10, one or more power conversion units 2 can be configured according to the requirements of the energy storage system 10. Here, an example in which the energy storage system 10 includes one power conversion unit 2 is introduced.

[0045] The power conversion unit 2 includes chips and some power devices such as inductors, electrolytic capacitors, or relays. These chips and power devices generate a large amount of heat during operation. If the power conversion unit 2 cannot be cooled in time, the performance of the chips and power devices will be affected. Based on this, the energy storage system 10 provided by the embodiments of the present application further includes a cooling unit 3 that can be used to liquid-cool the power conversion unit 2. It should be understood that the cooling unit 3 can be configured to only liquid-cool the power conversion unit 2, or can be configured to simultaneously liquid-cool the power conversion unit 2 and the battery unit 1. Here, only the architecture in which the cooling unit 3 liquid-cools the power conversion unit 2 is shown, without excluding the possibility that the cooling unit 3 can also liquid-cool the battery unit 1.

[0046] In actual application, the energy storage system 10 can exist in overload conditions such as current and voltage fluctuations and instantaneous overcurrent, which are different from the conventional working conditions. When the energy storage system 10 is in the overload condition, the power conversion unit 2 outputs a current multiple times the rated power, its power consumption increases, resulting in a large amount of real-time heat generated by the power conversion unit 2, and the power devices in the power conversion unit 2 have a risk of over-temperature failure, which also affects the function implementation of the power conversion unit 2. Therefore, the cooling unit 3 is required to have stronger cooling capacity, so that the energy storage system 10 has higher overload capacity to cope with the overload condition of the energy storage system 10. At the same time, the overload condition of the energy storage system 10 is a short-term special situation, and the operation of the energy storage system 10 is still mainly in the conventional working condition, so the power consumption of the energy storage system 10 in the conventional working condition also needs to be considered.

[0047] Figure 2An architecture diagram of the liquid cooling of the power conversion unit 2 by the heat dissipation unit 3 in the energy storage system 10 provided by the embodiment of the present application is shown. The power conversion unit 2 includes a plurality of power modules 21, and each power module 21 includes at least one chip and at least one power device. As shown in the figure, the heat dissipation unit 3 forms two independent liquid cooling circuits, and each liquid cooling circuit is used to circulate a cooling working medium. The two liquid cooling circuits are a first liquid cooling circuit L1 and a second liquid cooling circuit L2. Both of the two liquid cooling circuits can be used to cool the power conversion unit 2, and specifically, the first liquid cooling circuit L1 can be started to cool the power conversion unit 2, the second liquid cooling circuit L2 can be started to cool the power conversion unit 2, or both the first liquid cooling circuit L1 and the second liquid cooling circuit L2 can be started to cool the power conversion unit 2. Through the combination of the first liquid cooling circuit L1 and the second liquid cooling circuit L2, the heat dissipation unit 3 can have at least two heat dissipation modes, i.e., a first heat dissipation mode and a second heat dissipation mode. Figure 2 As shown in the figure, the heat dissipation unit 3 forms two independent liquid cooling circuits, and each liquid cooling circuit is used to circulate a cooling working medium. The two liquid cooling circuits are a first liquid cooling circuit L1 and a second liquid cooling circuit L2. Both of the two liquid cooling circuits can be used to cool the power conversion unit 2, and specifically, the first liquid cooling circuit L1 can be started to cool the power conversion unit 2, the second liquid cooling circuit L2 can be started to cool the power conversion unit 2, or both the first liquid cooling circuit L1 and the second liquid cooling circuit L2 can be started to cool the power conversion unit 2. Through the combination of the first liquid cooling circuit L1 and the second liquid cooling circuit L2, the heat dissipation unit 3 can have at least two heat dissipation modes, i.e., a first heat dissipation mode and a second heat dissipation mode.

[0048] In order to improve the overload capacity and operating energy efficiency of the energy storage system 10, in the embodiment of the present application, the power consumption and heat dissipation capacity of the heat dissipation unit 3 are different when the heat dissipation unit 3 operates in the first heat dissipation mode and the second heat dissipation mode. Specifically, the heat dissipation capacity of the heat dissipation unit 3 when operating in the first heat dissipation mode is lower than the heat dissipation capacity when operating in the second heat dissipation mode. That is, under the same environmental conditions, the heat dissipation efficiency of the heat dissipation unit 3 operating in the first heat dissipation mode is lower than the heat dissipation efficiency of the heat dissipation unit 3 operating in the second heat dissipation mode. When the energy storage system 10 is in a normal working condition, the heat dissipation unit 3 operates in the first heat dissipation mode to ensure that the energy storage system 10 operates at a lower energy consumption. When the energy storage system 10 is in an overload working condition, the heat dissipation unit 3 operates in the second heat dissipation mode to speed up the heat dissipation rate of the power conversion unit 2 and protect the power devices of the power conversion unit 2. The energy storage system 10 can switch between the first heat dissipation mode and the second heat dissipation mode according to the working condition of the energy storage system, thereby ensuring the energy efficiency in the normal working condition while maintaining a high overload capacity.

[0049] The determination of whether the energy storage system 10 is in a normal working condition or an overload working condition can be determined by the temperature of the power modules 21 of the power conversion unit 2, specifically the temperature of the chips in the power modules 21. Specifically, when the temperature of each power module 21 is less than a set temperature threshold, the energy storage system 10 is in a normal working condition. When the temperature of at least one power module 21 is greater than or equal to the set temperature threshold, the energy storage system 10 is in an overload working condition. When the power conversion unit 2 includes multiple power modules 21, and different power modules 21 have different temperature thresholds, the temperature of the power module with the lowest temperature threshold is used as the reference. For example, the temperature threshold of the first power module 21 is T1, and the temperature threshold of the second power module 21 is T2, where T1 is greater than T2. When the temperature of the second power module 21 is lower than T2, the heat dissipation unit 3 operates in the first heat dissipation mode, and when the temperature of the second power module 21 is higher than T2, the heat dissipation unit 3 operates in the second heat dissipation mode.

[0050] Please continue to refer to Figure 2 The power conversion unit 2 includes multiple power modules 21, and each power module 21 includes one or more power devices. The first liquid cooling circuit L1 passes through each power module 21 to liquid-cool each power module 21, and the second liquid cooling circuit L2 also passes through each power module 21 to liquid-cool each power module 21. That is, in order to liquid-cool each power module 21, each power module 21 is in the flow path of the two liquid cooling circuits, so that the heat generated by each power module 21 can be carried away by the cooling medium of the two liquid cooling circuits to achieve heat dissipation.

[0051] As Figure 3As shown, in some embodiments, the heat dissipation unit 3 can include a heat sink 31 and two heat exchangers, and the heat sink 31 has two liquid cooling channels independent of each other, one of which forms a liquid cooling loop with one of the heat exchangers through a liquid cooling pipe, and the other forms another liquid cooling loop with the other heat exchanger through a liquid cooling pipe. For example, the two heat exchangers are a first heat exchanger 32a and a second heat exchanger 32b, and the two liquid cooling channels are a first liquid cooling channel 311 and a second liquid cooling channel 312, the first heat exchanger 32a and the first liquid cooling channel 311 form a first liquid cooling loop L1 in series, and the second heat exchanger 32b and the second liquid cooling channel 312 form a second liquid cooling loop L2 in series. The plurality of power modules 21 included in the power conversion unit 2 are all arranged on the heat sink 31, and the orthogonal projection of any one power module 21 on the heat sink 31 at least partially overlaps with the first liquid cooling channel 311 and the second liquid cooling channel 312, and any one power module 21 is in the flow path of the first liquid cooling channel 311 and the second liquid cooling channel 312, that is, the first liquid cooling channel 311 and the second liquid cooling channel 312 are both in the heat dissipation path of each power module 21. When the cooling medium in the first liquid cooling channel 311 flows, it can exchange heat with each power module 21 through the heat sink 31 to carry away the heat of each power module 21. When the cooling medium in the second liquid cooling channel 312 flows, it can exchange heat with each power module 21 through the heat sink 31 to carry away the heat of each power module 21.

[0052] In the above embodiment, the power module 21 and the cooling medium in any one liquid cooling channel can be indirectly contacted through the physical structure of the heat sink 31, for example, the power module 21 is arranged on the surface of the shell of the heat sink 31, and the liquid cooling channel is formed in the interior of the shell of the heat sink 31, and the power module 21 can be indirectly contacted with the cooling medium in the liquid cooling channel through the shell of the heat sink 31 to realize heat exchange. Alternatively, the power module 21 and the cooling medium in any one liquid cooling channel can be directly contacted, for example, the liquid cooling channel is formed in the shell of the heat sink 31, the shell of the heat sink 31 has an opening communicating with the liquid cooling channel, and the power module 21 is arranged at the opening of the shell of the heat sink 31 and closes the opening, at this time, the edge of the power module 21 is connected with the edge of the opening of the heat sink 31, and the power module 21 can be contacted with the cooling medium in the liquid cooling channel through the opening to realize heat exchange.

[0053] The heat exchanger provided by the embodiments of the present application is used for heat exchange between the cooling medium in the liquid cooling pipeline and the outside, so as to reduce the temperature of the cooling medium in the liquid cooling pipeline. During the circulation of the liquid cooling medium in the liquid cooling loop, the heat of the power module 21 is taken away through heat exchange with the power module 21 by the radiator, and then the heat is released through heat exchange with the outside at the heat exchanger. The heat exchanger can be a wind-liquid heat exchanger, a plate heat exchanger, or other structures capable of dissipating the heat of the cooling medium in the liquid cooling loop to reduce the temperature of the cooling medium. In an embodiment, the heat exchanger is a combination structure of a heat dissipation structure and a fan. The heat dissipation structure can be connected in series in the liquid cooling loop for the cooling medium to flow through, and the cooling medium can exchange heat with the air outside through the heat dissipation structure when passing through the heat dissipation structure, so as to realize the temperature reduction of the cooling medium. The fan can accelerate the circulation of the air, thereby improving the efficiency of heat exchange. The pipeline for the cooling medium to flow through the heat dissipation structure can adopt a serpentine coil or a spiral coil, and the heat dissipation structure can be provided with a plurality of heat dissipation fins on the surface to increase the contact area of the heat dissipation structure and the air and improve the heat exchange efficiency.

[0054] Please continue to refer to Figure 3 As shown in FIG. 1, each liquid cooling loop further includes other functional devices. A control valve is connected in series between each heat exchanger and the liquid cooling channel connected thereto, and the control valve is used to control the opening and closing of the liquid cooling loop. A circulating pump is connected in series between each heat exchanger and the liquid cooling channel connected thereto, and the circulating pump is used to drive the flow of the cooling medium in the liquid cooling loop. Exemplarily, in the first liquid cooling loop L1, the first heat exchanger 32a and the first liquid cooling channel 311 are connected in series with the first control valve 33a and the first circulating pump 34a, and the first control valve 33a and the first circulating pump 34a are respectively arranged at the inlet and outlet of the first heat exchanger 32a, or can be considered to be arranged at the inlet and outlet of the first liquid cooling channel 311. In the second liquid cooling loop L2, the second heat exchanger 32b and the second liquid cooling channel 312 are connected in series with the second control valve 33b and the second circulating pump 34b, and the second control valve 33b and the second circulating pump 34b are respectively arranged at the inlet and outlet of the second heat exchanger 32b, or can be considered to be arranged at the inlet and outlet of the second liquid cooling channel 312. Of course, the positions of the control valve and the circulating pump are not limited, as long as they are connected in series in the liquid cooling loop.

[0055] The types of circulating pumps and control valves are not limited in this embodiment. It should be understood that the heat exchange capacity of the liquid cooling circuit is related to the type, temperature, flow rate, and flow volume of the cooling medium. The opening degree of the control valve can control the flow rate and flow volume of the cooling medium in the liquid cooling circuit, and the power of the circulating pump can affect the flow rate and flow volume of the cooling medium in the liquid cooling circuit. The two liquid cooling circuits provided in this embodiment can control the flow rate and flow volume of the cooling medium in the liquid cooling circuit by adjusting one or both of the control valves and circulating pumps. In specific implementations, the specific structure and composition of the two liquid cooling circuits of the heat dissipation unit 3 can also have other adaptive variations depending on the specific application scenario. For example, one of the two liquid cooling circuits may be equipped with a control valve and a circulating pump, while the other liquid cooling circuit may be equipped with other devices for controlling the flow of the cooling medium.

[0056] based on Figure 3 The configuration of the heat dissipation unit 3 and the power conversion unit 2 shown in this embodiment allows the heat dissipation unit 3 to operate in different heat dissipation modes as needed. Next, we will... Figure 3 The heat dissipation architecture shown is an exemplary description of the heat dissipation method of the power conversion unit 2 in the energy storage system 10 provided in this application.

[0057] Method 1

[0058] Under normal operating conditions, the heat dissipation unit 3 of the energy storage system 10 operates in the first heat dissipation mode: one liquid cooling circuit is turned on and the other liquid cooling circuit is turned off. Under overload conditions, the heat dissipation unit 3 of the energy storage system 10 operates in the second heat dissipation mode: both liquid cooling circuits are turned on.

[0059] like Figure 4a As shown, the heat dissipation unit 3 operates in the first heat dissipation mode. The first liquid cooling circuit L1 is activated to dissipate heat from the multiple power modules 21 of the power conversion unit 2, while the second liquid cooling circuit L2 is closed. Specifically, by controlling the first control valve 33a to open, the cooling medium in the first liquid cooling circuit L1 can circulate under the drive of the first circulation pump 34a, dissipating heat from the multiple power modules 21. When the second control valve 33b is closed, the second circulation pump 34b is closed, and the cooling medium in the second liquid cooling circuit L2 does not participate in liquid cooling. Alternatively, as... Figure 4b As shown, heat dissipation unit 3 operates in the first heat dissipation mode, the second liquid cooling circuit L2 is activated to dissipate heat for the multiple power modules 21 of power conversion unit 2, and the first liquid cooling circuit L1 is closed. Specifically, the second control valve 33b is opened, and the cooling medium in the second liquid cooling circuit L2 can circulate under the drive of the second circulation pump 34b to dissipate heat for the multiple power modules 21. When the first control valve 33a is closed and the first circulation pump 34a is closed, the cooling medium in the first liquid cooling circuit L1 does not participate in liquid cooling.

[0060] like Figure 5As shown, the heat dissipation unit 3 operates in the second heat dissipation mode, both the first liquid cooling loop L1 and the second liquid cooling loop L2 are activated to dissipate heat from the plurality of power modules 21 of the power conversion unit 2. Specifically, the first control valve 33a is controlled to be open, and the cooling medium in the first liquid cooling loop L1 can be circulated under the driving of the first circulating pump 34a to dissipate heat from the plurality of power modules 21. The second control valve 33b is controlled to be open, and the cooling medium in the second liquid cooling loop L2 can be circulated under the driving of the second circulating pump 34b to dissipate heat from the plurality of power modules 21. For each power module 21, both the cooling medium in the first liquid cooling loop L1 and the cooling medium in the second liquid cooling loop L2 can dissipate heat from the power module 21. In this second heat dissipation mode, both the first liquid cooling loop L1 and the second liquid cooling loop L2 are involved in the liquid cooling heat dissipation of the power conversion unit 2, which can accelerate the cooling speed of the power modules 21. The flow directions of the cooling medium in the first liquid cooling loop L1 and the second liquid cooling loop L2 can be the same or different.

[0061] Referring to Figure 4a and Figure 4b as well as Figure 5 The temperature of the cooling medium in the first liquid cooling loop L1 and the temperature of the cooling medium in the second liquid cooling loop L2 can be the same or different. When the energy storage system 10 is in the normal operating mode, only one liquid cooling loop is activated to dissipate heat from the plurality of power modules 21 of the power conversion unit 2, which can reduce the power consumption of the heat dissipation unit 3. When the energy storage system 10 is in the overload operating mode, both liquid cooling loops are activated to dissipate heat from the plurality of power modules 21 of the power conversion unit 2, which can more efficiently dissipate heat from the power conversion unit 2, reduce the heat consumption of the power conversion unit 2, prevent the power devices in the power modules 21 from overheating and failing, and improve the overload support capability of the power conversion unit 2.

[0062] In specific implementations, the temperature of the cooling medium in the second liquid cooling loop L2 can be reduced so that the temperature of the cooling medium in the second liquid cooling loop L2 is lower than the temperature of the cooling medium in the first liquid cooling loop L1. When the second heat dissipation mode is operated, the addition of the second liquid cooling loop L2 can further accelerate the heat dissipation rate.

[0063] Mode two

[0064] When the energy storage system 10 is in the normal operating mode, the heat dissipation unit 3 operates in the first heat dissipation mode: one liquid cooling loop is activated to dissipate heat from the plurality of power modules 21 of the power conversion unit 2 in a full-power state, and the other liquid cooling loop is activated to dissipate heat from the plurality of power modules 21 of the power conversion unit 2 in a low-power state. When the energy storage system 10 is in the overload operating mode, the heat dissipation unit 3 operates in the second heat dissipation mode: both liquid cooling loops of the heat dissipation unit 3 are activated to dissipate heat from the plurality of power modules 21 of the power conversion unit 2 in a full-power state.

[0065] The operating power of the liquid cooling circuit can be adjusted by controlling the opening degree of the valve and the power of the circulating pump.

[0066] Mode three

[0067] The two liquid cooling circuits of the heat dissipation unit 3 have different heat dissipation capacities. When the energy storage system 10 is in a normal working condition, the liquid cooling circuit with relatively weak heat dissipation capacity is used to dissipate heat for the power conversion unit 2, and when the energy storage system 10 is in an overload working condition, the liquid cooling circuit with relatively strong heat dissipation capacity is used.

[0068] In one embodiment, the cooling working medium in the two liquid cooling circuits has different temperatures. It is set that the temperature of the cooling working medium in the first liquid cooling circuit L1 is higher than that in the second liquid cooling circuit L2. When the energy storage system 10 is in a normal working condition, the heat dissipation unit 3 operates in a first heat dissipation mode: the first liquid cooling circuit L1 is opened and the second liquid cooling circuit L2 is closed. When the energy storage system 10 is in an overload working condition, the heat dissipation unit 3 operates in a second heat dissipation mode: the second liquid cooling circuit L2 is opened and the first liquid cooling circuit L1 is closed. In this embodiment, the first liquid cooling circuit L1 and the second liquid cooling circuit L2 are cooled by different cold sources respectively.

[0069] In one embodiment, the amount of cooling working medium flowing through the two liquid cooling circuits per unit time is different. It is set that the inner diameter of the channel of the first liquid cooling circuit L1 is larger than that of the second liquid cooling circuit L2, and the amount of cooling working medium flowing through the first liquid cooling circuit L1 per unit time is less than that of the second liquid cooling circuit L2. When the energy storage system 10 is in a normal working condition, the heat dissipation unit 3 operates in a first heat dissipation mode: the first liquid cooling circuit L1 is opened and the second liquid cooling circuit L2 is closed. When the energy storage system 10 is in an overload working condition, the heat dissipation unit 3 operates in a second heat dissipation mode: the second liquid cooling circuit L2 is opened and the first liquid cooling circuit L1 is closed. In this embodiment, the first liquid cooling circuit L1 and the second liquid cooling circuit L2 can be cooled by the same cold source.

[0070] It should be understood that the heat dissipation capacity of the two liquid cooling circuits of the heat dissipation unit 3 is also related to other parameters such as the type and flow rate of the cooling working medium, and in specific implementation, the application scenario can be debugged so that the heat dissipation unit 3 meets the heat dissipation demand while having relatively small power consumption in the first heat dissipation mode, and has relatively high heat dissipation capacity to speed up the cooling rate of the power conversion unit 2 in the second heat dissipation mode. The above three modes are only exemplary descriptions of specific embodiments.

[0071] In summary, the energy storage system 10 provided by the embodiment of the present application adopts a double-liquid cooling circuit design for the heat dissipation unit 3, which can adjust the working state of the two liquid cooling circuits according to different working modes of the energy storage system 10. When the energy storage system 10 is in a normal working condition, the lower power consumption can meet the liquid cooling heat dissipation of the power conversion unit 2, and when the energy storage system 10 is in an overload working condition, the higher heat dissipation efficiency can quickly cool the power conversion unit 2, thereby preventing the power devices of the power conversion unit 2 from overheating, failing or being damaged. The energy storage system 10 provided by the embodiment of the present application can adapt to high energy density and high power charging and discharging scenarios.

[0072] It should be noted that when the heat dissipation unit 3 can cool the battery unit 1 and the power conversion unit 2, the battery unit 1 and the power conversion unit 2 can be connected in series or parallel to the two liquid cooling circuits of the heat dissipation unit 3. When the battery unit 1 and the power conversion unit 2 are connected in parallel on the heat dissipation path of the heat dissipation unit 3, the heat dissipation demand of the battery unit 1 is higher than that of the power conversion unit 2 under the condition of high ambient temperature in summer, etc. The heat dissipation unit 3 selects the first heat dissipation mode with lower power consumption to cool the battery unit 1 and the power conversion unit 2, and the heat dissipation unit 3 can increase the compressor refrigeration in the heat dissipation unit 3 to cool the battery unit 1, and the power conversion unit 2 can meet the heat dissipation demand by using the liquid cooling of the heat dissipation unit 3, thereby improving the system energy efficiency.

[0073] In order to improve the automation and intelligence of the energy storage system 10, the adjustment of the two liquid cooling circuits of the heat dissipation unit 3 can be realized by electrical control. For example, Figure 6As shown, the energy storage system 10 further comprises a controller 4 capable of controlling the switching of the heat dissipation mode of the heat dissipation unit 3. Exemplarily, the controller 4 is electrically connected with the first control valve 33a of the first liquid cooling circuit L1, and the controller 4 is electrically connected with the second control valve 33b of the second liquid cooling circuit L2. The controller 4 can control the opening and closing and the opening degree of the first control valve 33a, and can also control the opening and closing and the opening degree of the second control valve 33b. The controller 4 is configured to: when the temperature of each power module 21 is less than a temperature threshold, control the first control valve 33a to be opened and the second control valve 33b to be closed to make the first liquid cooling channel 311 open to the cooling medium; and when the temperature of at least one power module 21 is greater than or equal to the temperature threshold, control the first control valve 33a and the second control valve 33b to be opened to make the first liquid cooling channel 311 and the second liquid cooling channel 312 open to the cooling medium. Alternatively, the controller 4 is configured to: when the temperature of each power module 21 is less than a temperature threshold, control the first control valve 33a to be opened and the second control valve 33b to be closed to make the first liquid cooling channel 311 open to the cooling medium; and when the temperature of at least one power module 21 is greater than or equal to the temperature threshold, control the second control valve 33b to be opened and the first control valve 33a to be closed to make the second liquid cooling channel 312 open to the cooling medium; wherein the temperature of the second liquid cooling channel 312 is lower than the temperature of the cooling medium in the first liquid cooling channel 311.

[0074] In some embodiments, the controller 4 can also be electrically connected with the first circulating pump 34a in the first liquid cooling circuit L1 and the second circulating pump 34b in the second liquid cooling circuit L2 respectively, and the controller 4 can control the working states of the two circulating pumps, so as to adjust the flow rate and flow of the cooling medium in the two liquid cooling circuits.

[0075] In the energy storage system 10 provided by the embodiments of the present application, the specific structure of the power conversion unit 2 can be configured according to the structure of the energy storage system 10.

[0076] In some embodiments, as Figure 7aAs shown, the power conversion unit 2 can include a direct current (DC) / alternating current (AC) converter 201, which can be used to convert the direct current output by the battery unit 1 into alternating current and output to the grid or the load, or convert the alternating current input from the grid into direct current and supply to the battery unit 1. The DC / AC converter 201 can also be referred to as a DC-AC converter. At this time, the power module included in the DC / AC converter 201 can be integrated in one box, and the heat sink 3 can liquid-cool the power module 21 included in the DC / AC converter 201. The power conversion unit 2 can also be referred to as a power conversion system (PCS), which is mainly used for converting direct current and alternating current, and can control the charging and discharging process of the battery unit 1.

[0077] As an example, the controller 4 included in the energy storage system 10 can be integrated in the power conversion unit 2 in the form of a control module 202. As shown, Figure 7a The control module 202 is electrically connected to the DC / AC converter 201 and can be used to control the DC / AC converter 201 to convert the direct current output by the battery unit 1 into alternating current and output to the load or the grid, or convert the alternating current input from the grid into direct current and supply to the battery unit 1. Here, the control module 202 is equivalent to the controller 4 in the above-mentioned embodiments, that is, the operation mode switching of the heat dissipation unit 3 can be controlled by the control module 202.

[0078] Please continue to refer to Figure 7a The energy storage system 10 can also include a plurality of DC / DC converters 203, wherein each DC / DC converter 203 is connected to each energy storage battery 11 of the battery unit 1 one by one. The DC / DC converter 203 can also be referred to as a DC-DC converter. The plurality of DC / DC converters 203 are connected in parallel to the DC / AC converter 201. Each DC / DC converter 203 is used to output the direct current output by the battery unit 1 to the DC / AC converter 201 or input the direct current input from the DC / AC converter 201 to the battery unit 1. The DC / DC converter 203 can be controlled by the control module 202. Specifically, the control module 202 can be used to control the DC / DC converter 203 to convert the direct current output by the battery unit 1 to the DC / AC converter 201 or input the direct current input from the DC / AC converter 201 to the battery unit 1.

[0079] As an example, in some embodiments, Figure 7bAs shown, the power conversion unit 2 can include a DC / AC converter 201 and at least one DC / DC conversion module connected between the battery unit 1 and the DC / AC converter 201 for converting electric energy between the battery unit 1 and the DC / AC converter 201. Specifically, the DC / DC conversion module includes a plurality of DC / DC converters 203, each of which is connected to each energy storage cell 11 of the battery unit 1 one-to-one. The plurality of DC / DC converters 203 are connected in parallel to the DC / AC converter 201 output. The power module 21 included in the DC / AC converter 201 and the DC / DC converter 202 can be integrated in one box, and the heat sink 3 can be liquid-cooled to the power module 21 included in the DC / AC converter 201 and the DC / DC converter 202.

[0080] Exemplarily, the controller 4 included in the energy storage system 10 can be integrated in the power conversion unit 2 in the form of a control module 202. As Figure 7b shown, the control module 202 is electrically connected to the DC / AC converter 201 and each DC / DC converter 203, respectively, and can be used to control the DC / AC converter 201 to convert the DC power output by the battery unit 1 into AC power to output to the load or the power grid, or to convert the AC power input by the power grid into DC power to supply to the battery unit 1.

[0081] Among them, the control module 202 here is equivalent to the controller 4 in the above-mentioned embodiments, that is, the operating mode switching of the heat dissipation unit 3 can be controlled by the control module 202. The DC / DC converter 203 can be controlled by the control module 202. Specifically, the control module 202 can be used to control the DC / DC converter 203 to convert power, so that the DC power output by the battery unit 1 is output to the DC / AC converter 201 or the DC power input by the DC / AC converter 201 is input to the battery unit 1.

[0082] In some embodiments, the controller 4 can control the heat dissipation unit 3 to switch between the first heat dissipation mode and the second heat dissipation mode according to the working condition of the energy storage system 10. In order to monitor the working condition of the energy storage system 10, the energy storage system 10 further includes a monitoring module 5 electrically connected to the controller 4. As Figure 8As shown, the monitoring module 5 is configured to monitor the working condition of the energy storage system 10, and the controller 4 is configured to process the monitoring data of the monitoring module 5 to obtain the temperature of each power module 21 in the power conversion unit 2. The working condition information of the energy storage system 10 includes the voltage at the input and output of the DC / AC converter 201 in the power conversion unit 2, the current at the output of the DC / AC converter 201, and the temperature of the heat sink 31 in the heat dissipation unit 3. According to the monitored voltage at the input and output of the DC / AC converter 201 in the power conversion unit 2, the current at the output of the DC / AC converter 201, and the temperature of the heat sink 31, the controller 4 can calculate the temperature of each power module 21 in the power conversion unit 2. When the temperature of each power module 21 is less than a set temperature threshold, the energy storage system 10 is considered to be in a normal working condition, and the heat dissipation unit 3 operates in the first heat dissipation mode. When the temperature of at least one power module 21 is greater than or equal to the set temperature threshold, the energy storage system 10 is considered to be in an overload working condition, and the heat dissipation unit 3 operates in the second heat dissipation mode. The voltage at the input and output of the DC / AC converter 201 and the current at the output of the DC / AC converter 201 can be used to calculate the heat loss of the power module 21, and the heat loss can be used to calculate the temperature rise of the power module 21 to the heat sink 31 according to the device parameters of the power module 21. Each power module 21 includes a chip, and the temperature of the power module 21 can be referred to as the temperature of the chip. The temperature of the chip can be considered as the sum of the temperature rise of each power module 21 to the heat sink 31 and the temperature of the heat sink 31.

[0083] As shown in the embodiment, the monitoring module 5 includes a voltage monitoring device 51, a current monitoring device 52, and a first temperature sensor 53 electrically connected to the controller 4, respectively. Figure 9a The voltage monitoring device 51 is configured to monitor the voltage at the input and output of the DC / AC converter 201 in the power conversion unit 2, the current monitoring device 52 is configured to monitor the current at the output of the DC / AC converter 201, and the first temperature sensor 53 is configured to monitor the temperature of the heat dissipation unit 3. The controller 4 can calculate the heat dissipation of the power module 21 according to the monitoring data of the voltage monitoring device 51, the current monitoring device 52, and the first temperature sensor 53, and further obtain the temperature of the power module 21. Here, the first temperature sensor 53 can be a negative temperature coefficient (NTC) sensor in the heat sink 31.

[0084] Alternatively, as shown in the embodiment, the monitoring module 5 includes a voltage monitoring device 51, a current monitoring device 52, and a first temperature sensor 53 electrically connected to the controller 4, respectively. Figure 9bAs shown, the operating information of the energy storage system 10 includes the temperature of each power module 21 in the power conversion unit 2. The monitoring module 5 directly monitors the temperature of each power module 21 in the power conversion unit 2 and adjusts the operating status of the heat dissipation unit 3 according to the temperature parameters of each power module 21. For example, the monitoring module 5 includes multiple second temperature sensors 54, each second temperature sensor 54 is electrically connected to the controller 4, and each second temperature sensor 54 is used to monitor the temperature of one power module 21. The controller 4 can control the operating mode of the heat dissipation unit 3 according to the data monitored by the second temperature sensors 54.

[0085] The energy storage system 10 provided in this embodiment uses a controller 4 and a monitoring module 5 to achieve intelligent real-time monitoring of the operating conditions of the energy storage system 10, improving the timeliness and accuracy of the control over the operating status of the energy storage system 10. In specific implementation, the acquisition of operating condition information of the energy storage system 10 may include... Figure 9a The methods shown may also include Figure 9b As shown, the operating condition information of the energy storage system 10 can be obtained from the temperature of each power module 21 in the power conversion unit 2 based on at least one of the two methods described above.

[0086] like Figure 9c The schematic diagram of the control principle of the energy storage system 10 shown indicates that the controller 4 can calculate the chip temperature based on the temperature of each power module 21 obtained from the monitoring module 5. Based on the comparison between this temperature and the set temperature, the controller 4 controls the first control valve 33a in the heat dissipation unit 3 to regulate the flow rate of the first liquid cooling circuit L1, and controls the second control valve 3b to regulate the flow rate of the first liquid cooling circuit L2. Alternatively, the controller 4 can control the first control valve 33a in the heat dissipation unit 3 to regulate the flow rate of the first liquid cooling circuit L1, and control the second control valve 3b to regulate the flow rate of the first liquid cooling circuit L2, based on the system's scheduling signal.

[0087] In a specific implementation, the energy storage system 10 provided in this application embodiment can house the battery unit 1, power conversion unit 2 and heat dissipation unit 3 in a cabinet. The cabinet can protect the various structures of the energy storage system 10 and facilitate the installation and transportation of the energy storage system 10 in different scenarios.

[0088] In some embodiments, the heat exchanger of the heat dissipation unit 3 can be installed on the side wall of the cabinet. An opening can be provided on the side wall of the cabinet to connect the inside of the cabinet with the outside. The heat exchanger can be fixed at the opening so that the heat exchanger can contact the external environment through the side wall of the cabinet, thereby dissipating the heat of the cooling medium in the liquid cooling circuit to the external environment and realizing heat dissipation of the cooling medium.

[0089] The energy storage system 10 provided by the embodiments of the present application can be electrically connected with a power grid or an external load to supply power to the power grid or the external load. Figure 10 FIG. 1 shows a schematic structural diagram of an example power supply system in which the energy storage system 10 is connected with a power grid. Figure 10 As shown, in actual use, the power supply system can be connected with the power grid through the power conversion unit 2 of the energy storage system 10 to grid-connect the generated power. The power conversion unit 2 of the energy storage system 10 can also be directly connected with a power consumption device to directly supply the generated power to the power consumption device, which can be regarded as a load of the power supply system.

[0090] Based on the architecture of the energy storage system 10 described above, the embodiments of the present application further provide a thermal management method of an energy storage system, which is used to regulate the heat dissipation mode of the power conversion unit 2. With reference to the structure shown in Figure 3 As shown, the energy storage system 10 can include the battery unit 1, the power conversion unit 2 and the heat dissipation unit 3, and the battery unit 1 is electrically connected with the power conversion unit 2. The heat dissipation unit 3 is formed with two independent liquid cooling circuits, which are divided into a first liquid cooling circuit L1 and a second liquid cooling circuit L2. The two liquid cooling circuits can be configured to enable the heat dissipation unit 3 to have a first heat dissipation mode and a second heat dissipation mode.

[0091] As shown, the thermal management method of the energy storage system includes the following steps: Figure 11

[0092] S111: Obtain the working condition information of the energy storage system and obtain the temperature of each power module according to the working condition information.

[0093] The working condition information of the energy storage system 10 includes the voltage of the power conversion unit 2, the current of the power conversion unit 2 and the temperature of the heat dissipation unit 3. Specifically, the voltage of the input end and the output end of the direct current / alternating current converter 201 in the power conversion unit 2 can be monitored by a voltage monitoring device, the current of the output end of the direct current / alternating current converter 201 in the power conversion unit 2 can be monitored by a current monitoring device, and the temperature of the heat dissipation unit 3 can be monitored by a first temperature sensor 53. The controller 4 can obtain these information and calculate the temperature of the chip in the power module 21 in the power conversion unit 2.

[0094] Alternatively, the working condition information of the energy storage system 10 includes the temperature of the power module 21. Specifically, the temperature of the power module 21 can be monitored by a second temperature sensor 54.

[0095] S112: Adjust the flow rate of the cooling working medium in the first liquid cooling channel and the flow rate of the cooling working medium in the second liquid cooling channel according to the temperature of the power module.

[0096] Specifically, in some embodiments, as Figure 12 ​As shown, step S112 can include:

[0097] S121: in response to the temperature of each power module being less than the temperature threshold, introducing the cooling working medium into the first liquid cooling channel.

[0098] When the temperature of each power module 21 in the power conversion unit 2 is lower than the temperature threshold, the energy storage system 10 is in a normal working condition, and the first heat dissipation mode with weaker heat dissipation capacity can be used to liquid-cool the power conversion unit 2, that is, the heat dissipation demand of the power conversion unit 2 can be met. At this time, the heat dissipation unit 3 has lower power consumption, and can improve the energy efficiency of the energy storage system 10 while meeting the heat dissipation demand.

[0099] In step S121, the first liquid cooling circuit L1 can be started to dissipate heat from the power conversion unit 2, and the second circuit L2 can be closed. Specifically, the first control valve 33a of the first liquid cooling circuit L1 can be controlled by the controller 4 to open the first liquid cooling circuit L1, so that the cooling working medium in the first liquid cooling circuit L1 flows through the first liquid cooling channel 311 of the heat sink 31 in circulation to take away the heat of the plurality of power modules 21 in the power conversion unit 2. At this time, the second liquid cooling circuit L2 can not participate in the heat dissipation of the power conversion unit 2, thereby saving system energy consumption.

[0100] S122: in response to the temperature of at least one of the power modules being greater than or equal to the temperature threshold, introducing the cooling working medium into the first liquid cooling channel and the second liquid cooling channel, respectively.

[0101] When the temperature of at least one of the power modules 21 in the power conversion unit 2 is higher than or equal to the temperature threshold, the energy storage system 10 is in an overload working condition, and the second heat dissipation mode with stronger heat dissipation capacity can be used to liquid-cool the power conversion unit 2, so as to meet the heat dissipation demand of the power conversion unit 2. At this time, the heat dissipation unit 3 can liquid-cool the power conversion unit 2 more quickly to prevent the power modules 21 in the power conversion unit 2 from overheating, failing or being damaged.

[0102] In step S122, the first circuit can be started to dissipate heat from the power conversion unit, and the second circuit can be started to dissipate heat from the power conversion unit. Specifically, the first control valve 33a of the first liquid cooling circuit L1 can be controlled by the controller 4 to open the first liquid cooling circuit L1, and the second control valve 33b of the second liquid cooling circuit L2 can be controlled by the controller 4 to open the second liquid cooling circuit L2, so that the cooling working medium in the first liquid cooling circuit L1 and the cooling working medium in the second liquid cooling circuit L2 flow through the first liquid cooling channel 311 of the heat sink 31 in circulation to take away the heat of the plurality of power modules 21 in the power conversion unit 2. The two liquid cooling circuits simultaneously liquid-cool the power conversion unit 2 to accelerate the heat dissipation of the power conversion unit 2. The opening of the first liquid cooling circuit L1 and the second liquid cooling circuit L2 has no sequence, and they can be opened simultaneously.

[0103] It should be understood that when the energy storage system 10 is converted from the normal operating condition of opening the first liquid cooling circuit L1 to the overload operating condition, the first liquid cooling circuit L1 can not be operated, and the second liquid cooling circuit L2 can be directly opened to convert to the second heat dissipation mode.

[0104] In some embodiments, the temperature of the cooling medium in the first liquid cooling circuit L1 can be lower than the temperature of the cooling medium in the second liquid cooling circuit L2. The first heat dissipation mode of the heat dissipation unit 3 is to open the first liquid cooling circuit L1 to liquid cooling heat dissipation for the power conversion unit 2, and the second heat dissipation mode of the heat dissipation unit 3 is to open the second liquid cooling circuit L2 to liquid cooling heat dissipation for the power conversion unit 2. As Figure 13 As shown, step S112 can include:

[0105] S131: In response to the temperature of each power module being less than the temperature threshold, the cooling medium is introduced into the first liquid cooling channel.

[0106] This step S131 is similar to step S121 in Figure 12 , which will not be described here.

[0107] S132: In response to the temperature of at least one of the power modules being greater than or equal to the temperature threshold, the cooling medium is introduced into the second liquid cooling channel, and the temperature of the cooling medium in the second liquid cooling channel is lower than the temperature of the cooling medium in the first liquid cooling channel.

[0108] Specifically, the second control valve 33b of the second liquid cooling circuit L2 can be controlled by the controller 4 to open the second liquid cooling circuit L2, so that the cooling medium in the second liquid cooling circuit L2 circulates through the second liquid cooling channel 312 of the heat sink 31 respectively, and carries away the heat of the plurality of power modules 21 in the power conversion unit 2. The cooling medium with lower temperature in the second liquid cooling circuit L2 can accelerate the heat dissipation of the power conversion unit 2.

[0109] In combination with Figure 14 , the operation logic of one of the embodiments of the heat management method of the energy storage system provided by the present application is exemplarily described. Specifically, the heat management method includes:

[0110] First, execute S141: obtain the operating condition information of the energy storage system. The operating condition information of the energy storage system 10 includes the voltage at the input and output ends of the DC / AC converter 201 in the power conversion unit 2, the current at the output end of the DC / AC converter 201 in the power conversion unit 2, and the temperature of the heat dissipation unit 3. Alternatively, the operating condition information of the energy storage system 10 includes the temperature of each power module 21 of the power conversion unit 2.

[0111] According to the working condition information of the energy storage system, S142 is performed: the temperature of each power module in the power conversion unit is calculated. It is provided that the temperature of each power module 21 of the power conversion unit 2 is Tj. It should be understood that the temperature of each power module 21 can be considered as the temperature of the chip of the power module 21.

[0112] In combination with the temperature of each power module 21 of the power conversion unit 2 being Tj, S143 is performed: it is judged whether Tj is greater than or equal to Test. If yes, S144 is performed, otherwise, S145 is performed.

[0113] Wherein, S144: the heat dissipation unit operates the second heat dissipation mode. S145: the heat dissipation unit operates the first heat dissipation mode. Test is the temperature of each power module 21 of the power conversion unit 2 when operating within the rated load, which can be considered as the temperature threshold of each power module 21 of the power conversion unit 2.

[0114] After S144 or S145 is operated, the process continues to start and enters the heat management method judgment process of the energy storage system again. That is, the acquisition of the working condition information of the energy storage system 10 is always carried out continuously, and the control of the heat dissipation unit 3 to switch between the first heat dissipation mode and the second heat dissipation mode according to the working condition information of the energy storage system 10 is a dynamic cycle process, so as to dynamically regulate and control the heat dissipation of the power conversion unit 2 of the energy storage system, so as to ensure the normal operation of the energy storage system 10, and make the energy storage system 10 maintain a higher overload capacity to cope with short-time overload or power grid fluctuation.

[0115] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An energy storage system, characterized in that, The energy storage system includes battery units, power conversion units, and heat sinks; The battery unit is electrically connected to the power conversion unit. The power conversion unit is used to convert the electrical energy output by the battery unit into power and output it to the load or the power grid, or to convert the electrical energy input from the power grid into power and provide it to the battery unit. The radiator includes a first liquid cooling channel and a second liquid cooling channel that are independent of each other. The power conversion unit includes multiple power modules that are fitted to the heat sink. When the temperature of each power module is below the temperature threshold, the first liquid cooling channel is used to introduce cooling medium; when the temperature of at least one power module is greater than or equal to the temperature threshold, both the first liquid cooling channel and the second liquid cooling channel are used to introduce cooling medium. Alternatively, when the temperature of each of the power modules is below the temperature threshold, the first liquid cooling channel is used to circulate the cooling medium; when the temperature of at least one of the power modules is greater than or equal to the temperature threshold, the second liquid cooling channel is used to circulate the cooling medium, and the temperature of the cooling medium in the second liquid cooling channel is lower than the temperature of the cooling medium in the first liquid cooling channel.

2. The energy storage system as described in claim 1, characterized in that, The energy storage system also includes two liquid-cooled pipes and two heat exchangers. The first liquid-cooled channel is connected in series with one of the heat exchangers and is connected in series through one of the liquid-cooled pipes to form a first liquid-cooled loop for circulating cooling working fluid. The second liquid-cooled channel is connected in series with the other heat exchanger and is connected in series through another liquid-cooled pipe to form a second liquid-cooled loop for circulating cooling working fluid. Each heat exchanger is used to exchange heat between the cooling medium inside the liquid-cooled pipe and the outside environment.

3. The energy storage system as described in claim 2, characterized in that, The power conversion unit includes a controller; The first liquid cooling circuit includes a first control valve disposed on the liquid cooling pipe, the first control valve being used to regulate the flow rate of the cooling medium in the first liquid cooling pipe; the second liquid cooling circuit includes a second control valve disposed on the liquid cooling pipe, the second control valve being used to regulate the flow rate of the cooling medium in the second liquid cooling pipe. The controller is configured to: when the temperature of each power module is less than the temperature threshold, control the first control valve to open and control the second control valve to close so that the first liquid cooling channel is circulated with cooling medium; and when the temperature of at least one power module is greater than or equal to the temperature threshold, control both the first control valve and the second control valve to open so that the first liquid cooling channel and the second liquid cooling channel are circulated with cooling medium. Alternatively, the controller is configured to: when the temperature of each of the power modules is less than a temperature threshold, control the first control valve to open and control the second control valve to close so that a cooling medium is introduced into the first liquid cooling channel; when the temperature of at least one of the power modules is greater than or equal to the temperature threshold, control the second control valve to open and control the first control valve to close so that a cooling medium is introduced into the second liquid cooling channel, and the temperature of the cooling medium in the second liquid cooling channel is lower than the temperature of the cooling medium in the first liquid cooling channel.

4. The energy storage system as described in claim 3, characterized in that, The power conversion unit includes a DC / AC converter, and the controller is further configured to control the DC / AC converter to perform power conversion so that the DC power output by the battery unit is converted into AC power and output to the load or the power grid, or to convert the AC power input from the power grid into DC power and supply it to the battery unit.

5. The energy storage system as described in claim 3, characterized in that, The power conversion unit includes a DC / DC converter and a DC / AC converter. The controller is also used to control the DC / DC converter to perform power conversion so that the DC power output from the battery cell is output to the DC / AC converter or the DC power input from the DC / AC converter is input to the battery cell. The controller is also used to control the DC-AC converter to convert the DC output of the DC / DC converter into AC output to the load or the power grid, or to convert the AC input from the power grid into DC output to the DC / DC converter.

6. The energy storage system as described in claim 4 or 5, characterized in that, The energy storage system includes a monitoring module, which includes a voltage monitoring device, a current monitoring device, and a first temperature sensor, all of which are electrically connected to the controller. The voltage monitoring device is used to monitor the voltage at the input and output terminals of the DC / AC converter, the current monitoring device is used to monitor the current at the output terminal of the DC / AC converter, the first temperature sensor is used to monitor the temperature of the heat sink, and the controller is used to calculate the temperature of the multiple power modules of the power conversion unit based on the voltage at the input and output terminals of the DC / AC converter, the current at the output terminal of the DC / AC converter, and the temperature of the heat sink.

7. The energy storage system according to any one of claims 1-6, characterized in that, The energy storage system includes a cabinet, in which the battery unit, the power conversion unit, and the heat sink are all housed.

8. The energy storage system as described in claim 7, characterized in that, The energy storage system includes two heat exchangers, which are respectively connected to the two liquid cooling channels of the radiator to form two liquid cooling circuits; The cabinet has an opening that penetrates the side wall, and the heat exchanger is fixed to the opening.

9. A thermal management method for an energy storage system, characterized in that, The energy storage system includes a battery unit, a power conversion unit, and a heat sink. The battery unit is electrically connected to the power conversion unit. The heat sink includes a first liquid cooling channel and a second liquid cooling channel that are independent of each other. The power conversion unit includes multiple power modules fixed to the heat sink, and the orthographic projection of each power module on the heat sink at least partially overlaps with the path of each liquid cooling channel. The thermal management method includes: Obtain the operating condition information of the energy storage system and, based on the operating condition information, determine the temperature of each power module in the power conversion unit; The flow rates of the cooling medium in the first liquid cooling channel and the second liquid cooling channel are adjusted according to the temperatures of the multiple power modules.

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