Multi-cell rechargeable energy storage system

Abstract

Multi-cell rechargeable energy storage system, RESS, (24) comprising: a plurality of battery cells (28) arranged in individual battery modules (30-1, 30-2, 30-3); and a cooling system (36) comprising: a main coolant circuit (38) configured to circulate a coolant (40); a plurality of coolant branches (44-1, 44-2, 44-3) arranged in parallel, each coolant branch (44-1, 44-2, 44-3) being configured to receive a portion of the coolant (40) from the main coolant circuit (38) to remove thermal energy from one of the corresponding battery modules (30-1, 30-2, 30-3); and at least one flow valve (50) configured to regulate the coolant (40) circulating through the main coolant circuit (38) and to distribute it to the multitude of coolant branches (44-1, 44-2, 44-3);wherein each coolant branch (44-1, 44-2, 44-3) contains a one-way valve (52-1, 52-2, 52-3) configured to control the flow of coolant (40) from the coolant branch (44-1, 44-2, 44-3) in question.

Description

The present disclosure relates to a multi-cell rechargeable energy storage system (RESS). A battery system for generating and storing electrical energy typically includes one or more battery cells to power a load. Multiple battery cells can be arranged in close proximity to each other to form a battery module, and multiple battery modules can be combined to form a battery pack array. Batteries can be broadly divided into primary and secondary batteries. Primary batteries, also known as disposable batteries, are designed to be used until depleted and then simply replaced with new ones. Secondary batteries, commonly referred to as rechargeable batteries, utilize a special chemistry that allows them to be repeatedly recharged and reused, offering economic, environmental, and user-friendliness advantages compared to disposable batteries. Rechargeable batteries can be used to power a wide variety of items, from toys and consumer electronics to motor vehicles. Certain chemical properties of rechargeable batteries, such as lithium-ion cells, as well as external factors, can lead to internal reaction rates that generate significant amounts of thermal energy. If a battery cell is exposed to high temperatures for an extended period, thermal runaway can occur, in which heat from a single cell spreads to neighboring cells in the module, affecting the entire battery assembly. Accordingly, the thermal energy must be effectively dissipated to reduce heat buildup and the resulting performance degradation of the battery system. Generally, devices such as heat sinks or cooling plates with circulating coolant are used to remove heat from battery systems. GB 2 561 209 A describes an energy storage module cooling system for an energy storage system comprising at least one energy storage module or a cabin housing at least one energy storage module, a coolant source, and a plurality of fluid lines for supplying coolant to the stored energy storage module or cabin. Each fluid line entering each module or cabin is equipped with a flow control valve and one or more sensors connected to each valve and each module. A signal controls the degree of opening of each valve to regulate the amount of coolant. DE 10 2009 013 651 A1 describes a cooling system for an energy storage device made of battery cells and a method for dimensioning passive cooling or controlling active cooling. The cooling system has a coolant inlet, a coolant outlet, and a coolant distributor. The coolant distributor has flow restrictors that distribute the coolant flow in such a way that different areas of battery cells within a battery housing have different cooling levels. DE 10 2015 115 148 A1 describes a thermal management system for a battery pack comprising a conductive cooling plate and battery cells, including a compressor, flow control valves, one or more temperature sensors, and a controller. The compressor circulates refrigerant through the plate to cool the cells. The temperature sensor measures the temperature of the battery pack. The controller is programmed to receive the temperature from the temperature sensors and selectively transmit switching control signals to the valves to instruct a change in the direction or flow of the refrigerant through the cooling plate. This limits temperature variation between the battery cells over time. A vehicle has a transmission, an electric traction motor, a battery pack, and the thermal management system as described above.One method involves receiving the temperature, transmitting switching control signals to the valves, and controlling the flow of refrigerant through the plate via the valves in response to the switching control signals. Accordingly, the object of the present invention is to provide a system that effectively dissipates heat energy in order to minimize heat build-up and power reduction. The problem is solved by the subject matter of the independent claims. A multi-cell rechargeable energy storage system (RESS) according to the invention comprises a plurality of battery cells arranged in individual battery modules. The RESS also includes a cooling system with a main coolant circuit designed for the circulation of a coolant. The RESS further comprises a plurality of coolant branches arranged in parallel. Each coolant branch is configured to receive a portion of the coolant from the main coolant circuit to remove heat energy from one of the respective battery modules. Additional parallel cooling branches can be used for the circulation of coolant through other internal battery components that require liquid cooling, such as a battery disconnect unit (BDU), electrical connectors, and a DC / DC converter for supplying the vehicle with 12 V / 48 V power.The RESS further comprises at least one flow-through valve configured to regulate the coolant circulating through the main coolant circuit and to distribute it to the multiple coolant branches. Each coolant branch contains a one-way valve configured to control the flow of coolant out of that branch. The flow control valve can be a multi-way valve assembly located at a connection between the main coolant circuit and the multiple coolant branches. Such a multi-way valve can be configured to control the flow of coolant into each of the coolant branches. Alternatively, a number of throttle valves can regulate the flow of coolant from the main coolant circuit. Each throttle valve can be located in one of the coolant branches upstream of the corresponding battery module and configured to control the flow of coolant into that specific coolant branch. The cooling system may also include a fluid pump configured to circulate the coolant through the main coolant circuit. The cooling system may additionally include a coolant cooler configured to extract thermal energy from the coolant in the main coolant circuit. The cooling system may also include a coolant heater configured to supply thermal energy to the coolant in the main coolant circuit. The multi-cell RESS can also include an electronic control unit configured to regulate the operation of the flow valve(s), fluid pump, coolant cooler, and coolant heater. The electronic control unit can be configured to regulate the temperature of individual battery modules via the fluid pump, coolant radiator, and / or coolant heater. The electronic control unit can also regulate the temperature of other components or subsystems, such as the battery distribution unit (BDU), electrical connections, and DC / DC converter. The electronic control can additionally be configured to regulate the temperature of the individual battery modules by distributing the flow of coolant via the flow valve(s) to the multitude of coolant branches. A motor vehicle according to the invention, which uses a rechargeable multi-cell rechargeable energy storage system (RESS) according to the invention with the cooling system described above, is also disclosed. The above features and advantages, as well as other features and advantages of the present disclosure, will be readily apparent from the following detailed description of the embodiment(s) and best embodiment(s) of the disclosed disclosure in conjunction with the accompanying drawings and claims. Fig. 1 is a schematic top view of an embodiment of a motor vehicle with multiple energy sources and a multi-cell rechargeable energy storage system (RESS) configured to generate and store electrical energy used by vehicle systems, including the energy sources according to the disclosure. Fig. 2 is a schematic representation of the RESS shown in Fig. 1, including an embodiment of a coolant system with a main coolant circuit and multiple parallel coolant branches as a subsystem for dissipating heat energy from individual battery modules according to the disclosure.Figure 3 is a schematic representation of the RESS shown in Fig. 1, including a further embodiment of a coolant system with a main coolant circuit and several parallel coolant branches as a subsystem for dissipating heat energy from individual battery modules according to the disclosure. With reference to the drawings, where similar reference numerals denote similar components, Fig. 1 shows a schematic view of a motor vehicle 10 with a powertrain 12. The vehicle 10 may be, but is not limited to, a commercial vehicle, an industrial vehicle, a passenger vehicle, an aircraft, a watercraft, a train, or the like. It is also conceivable that the vehicle 10 is a mobile platform, such as an aircraft, an all-terrain vehicle (ATV), a boat, a personal mobility device, a robot, or the like, to serve the purposes of this disclosure. The powertrain 12 comprises a power source 14 configured to generate a power source torque T (shown in Fig. 1) for driving the vehicle 10 via driven wheels 16 relative to a road surface 18. The power source 14 is represented as an electric motor-generator. As shown in Fig. 1, the powertrain 12 can include an additional power source 20, such as an internal combustion engine. The power sources 14 and 20 can work together to power the vehicle 10. The vehicle 10 also includes a central processing unit (CPU) 22 and a multi-cell rechargeable energy storage system (RESS) 24, which is configured to generate and store electrical energy through heat-generating electrochemical reactions to supply the electrical energy to the power sources 14 and 20. The CPU 22 controls various systems of the vehicle 10, including the powertrain 12, to generate a predetermined torque T from the power source. The RESS 24 can be connected to the power sources 14 and 20, the CPU 22, and other vehicle systems via a high-voltage bus 25. As shown in Figures 1-3, the RESS 24 comprises a plurality of battery cells 28 arranged in individual battery groups or modules, such as a first module 30-1, a second module 30-2, and a third module 30-3. The modules 30-1, 30-2, 30-3 in question can be arranged electrically in series or in parallel. Although three individual battery modules are specifically shown, it is intended that the RESS 24 comprises at least two such modules, and several modules can be organized into battery packs or subpacks. The remainder of this disclosure focuses on the construction of the RESS 24 with three battery modules 30-1, 30-2, 30-3, each battery module having a desired number of battery cells 28. As shown in Figures 2 and 3, the RESS 24 comprises three battery modules 30-1, 30-2, 30-3, each of which has a desired number of battery cells 28.As shown in Figure 3, each battery module 30-1, 30-2, 30-3 can include a corresponding battery module housing 32-1, 32-2, 32-3, configured to accommodate and support the corresponding battery cells 28. The RESS 24 can also include a battery housing 33 surrounded by an environment 34. The housing 33 of the battery set is configured to accommodate and support the battery modules 30-1, 30-2, 30-3. As shown in Figures 2 and 3, the RESS 24 also includes a cooling system 36 configured to dissipate thermal energy from various temperature-sensitive components of the RESS. The cooling system 36 includes a main coolant circuit 38 configured to circulate a coolant 40 through the RESS 24. As shown, the cooling system 36 also includes a fluid pump 42 configured to circulate the coolant 40 through the main coolant circuit 38. The cooling system 36 also includes a plurality of coolant branches, shown as a first branch 44-1, a second branch 44-2, and a third branch 44-3, which are in fluid communication with the main coolant circuit 38. Each of the coolant branches 44-1, 44-2, 44-3 extends through a corresponding battery module 30-1, 30-2, 30-3 near and along the associated battery cells 28. Furthermore, each coolant branch 44-1, 44-2, 44-3 is configured to receive a portion of the coolant 40 from the main coolant circuit 38. The coolant branches 44-1, 44-2, 44-3 are arranged in parallel fluid flow to receive corresponding portions of the coolant 40. The coolant branches 44-1, 44-2, 44-3 are configured to independently circulate their respective portions of the coolant 40 and remove thermal energy from the corresponding battery modules 30-1, 30-2, 30-3. As shown, the main coolant circuit 38 can be in fluid connection with additional parallel coolant branches, for example to circulate the coolant through auxiliary power modules (APMs), a battery disconnect unit (BDU) with various electrical switches and relays, electrical connectors, a DC / DC converter to supply the vehicle with 12 V / 48 V, etc., each of which has a specific temperature requirement. With further reference to Figures 2 and 3, the RESS 24 can also include an inlet distributor 46 configured to connect the main coolant circuit 38 to the coolant branches 44-1, 44-2, 44-3, and an outlet distributor 48 configured to reconnect the coolant branches to the main coolant circuit. Accordingly, the inlet distributor 46 and outlet distributor 48 together are designed to maintain the circulation of the coolant 40 through the cooling system 36. The cooling system 36 additionally includes at least one flow valve 50. The flow valve(s) 50 is (are) configured to regulate (regulate) the coolant 40 that circulates through and is received by the main coolant circuit 38 and to distribute (distribute) it to the individual coolant branches 44-1, 44-2, 44-3.In other words, the flow valve(s) 50 is / are specifically designed and operated to independently regulate the coolant flow in each individual coolant branch 44-1, 44-2, 44-3. As shown in Fig. 2, the flow valve 50 can be a multi-way valve arrangement located in a connection, such as the inlet manifold 46, between the main coolant circuit 38 and the plurality of coolant branches 44-1, 44-2, 44-3 upstream of each battery module 30-1, 30-2, 30-3. The embodiment of the flow valve 50 as a multi-way valve arrangement can be configured to control the flow of the coolant 40 into each of the coolant branches 44-1, 44-2, 44-3. As shown in Fig. 3, the flow valve(s) 50 can be a plurality of individual throttle valves 50-1, 50-2, 50-3. Each individual throttle valve 50-1, 50-2, 50-3 can be arranged in one of the plurality of coolant branches 44-1, 44-2, 44-3 upstream of the corresponding battery module 30-1, 30-2, 30-3 and configured to control the flow of the coolant 40 into the coolant branch concerned. As shown in Figures 2 and 3, each coolant branch 44-1, 44-2, 44-3 can contain a corresponding one-way valve 52-1, 52-2, 52-3. The one-way valves 52-1, 52-2, 52-3 are configured to prevent backflow of the coolant 40 into the corresponding coolant branches 44-1, 44-2, 44-3. Each of the one-way valves 52-1, 52-2, 52-3 is located downstream of the flow valve(s) 50 and downstream of the corresponding battery module 30-1, 30-2, 30-3. Accordingly, each one-way valve 52-1, 52-2, 52-3 is configured to control the flow of the corresponding portion of the coolant 40 through and out of the respective coolant branch 44-1, 44-2, 44-3. The cooling system 36 may also include a plurality of heat exchangers arranged in the main coolant circuit 38 to modify the temperature of the coolant 40.One embodiment of such a heat exchanger can be, for example, a coolant cooler 54-1, which uses a refrigerant to extract thermal energy from the coolant 40 in the main coolant circuit 38. Another embodiment of such a heat exchanger can be a coolant heater 54-2, which, for example, uses an electrical resistor to supply thermal energy to the coolant 40. As shown in Figures 2 and 3, the multi-cell RESS 24 can additionally include an electronic control unit 56, which can either be electronically connected to the CPU 22 or be part of it. The electronic control unit 56 can be configured or programmed to regulate the operation of the cooling system 36, or it can be designed to control the operation of the RESS 24 as a whole. As shown, the electronic control unit 56 is in established communication with the fluid pump 42, the flow valve(s) 50, the coolant cooler 54-1, and the coolant heater 54-2. To support the necessary management of the RESS 24 and / or the cooling system 36, the electronic control unit 56 includes, in particular, a processor and tangible, non-volatile memory in which the necessary instructions are programmed.The controller's memory can be a suitable writable medium involved in providing computer-readable data or process instructions. Such a writable medium can take many forms, including, but not limited to, non-volatile and volatile media. Non-volatile media for the electronic control 56 can include, for example, optical or magnetic disks and other permanent storage media. Volatile media can include, for example, dynamic random-access memory (DRAM), which can represent main memory. The instructions programmed into the control 56 can be transmitted via one or more transmission media, including coaxial cable, copper wire, and fiber optic cable, including lines that have a system bus coupled to a computer processor, or via a wireless connection. The memory of the electronic control 56 can also include a flexible disk, a hard disk, magnetic tape, another magnetic medium, a CD-ROM, a DVD, another optical medium, etc. The electronic control 56 can be configured or equipped with other necessary computer hardware, such as...with a high-speed clock generator, required analog-to-digital (A / D) and / or digital-to-analog (D / A) circuits, input / output (I / O) circuits and devices, and suitable signal conditioning and / or buffer circuits. The algorithm(s) required by or accessible through the electronic control 56 can be stored in the control's memory and executed automatically to enable the operation of the RESS 24 and / or the cooling system 36. In particular, the algorithm(s) 58 can include a maintenance mode configured to monitor the operation of the fluid pump 42, the flow valve(s) 50, the coolant radiator 54-1, and the coolant heater 54-2. The electronic control 56 can be configured to control the temperature of the individual battery modules 30-1, 30-2, 30-3 via at least one of the components fluid pump 42, coolant radiator 54-1, and coolant heater 54-2. The electronic control 56 can further be configured, for example, to…via the algorithm(s) 58, that it regulates the temperature of the individual battery modules 30-1, 30-2, 30-3 by dividing the flow of the coolant 40 between the individual coolant branches 44-1, 44-2, 44-3 via the flow valve(s) 50. The RESS 24 can, for example, also include individual temperature sensors 60-1, 60-2, 60-3, which are embedded in the corresponding battery modules 30-1, 30-2, 30-3 (as well as in the respective temperature sensors in the auxiliary power modules and the components of the subsystem, such as the BDU, the electrical connectors, and the aforementioned DC / DC converter) and are connected to the electronic control unit 56. The electronic control unit 56 can be programmed to receive temperature signals from the respective sensors 60-1, 60-2, 60-3 and compare the detected temperatures with a predetermined permissible temperature range 62 for the required operation of the corresponding battery modules 30-1, 30-2, 30-3 (and, using signals from additional dedicated sensors, compare the temperatures of auxiliary power modules and subsystem components). Such an permissible temperature range 62 can be empirically determined for a variety of operating modes, e.g.B. Cold start, continuous operation or heavy load operation of the RESS 24 and the vehicle 10. The sensors 60-1, 60-2, 60-3 can also be used to control the cooling system 36 in a closed-loop system to stabilize the temperature of the battery modules 30-1, 30-2, 30-3 (as well as the auxiliary power modules and the components of the subsystem). If the temperature detected by one or more sensors 60-1, 60-2, 60-3 (or auxiliary power modules and subsystem components) is outside the permissible temperature range 62, the electronic control 56 can instruct the fluid pump 42 to increase or decrease the flow rate of the coolant 40 and to lower or raise the temperature of the coolant via the coolant cooler 54-1 or the coolant heater 54-2. Furthermore, the electronic control 56 can divide the flow of the coolant 40 between the individual coolant branches 44-1, 44-2, 44-3 by regulating the flow valve(s) 50.As a result, the coolant flow with increased or decreased temperature can be directed with a larger or smaller volume flow to one or more specific coolant branches 44-1, 44-2, 44-3 of the corresponding battery modules that are outside the permissible temperature range 62. Overall, the structure of the parallel coolant branches of the cooling system 36 enables controlled distribution of the coolant to the individual battery modules. The flow valve(s) 50 upstream of the individual battery modules allows the subject to control the coolant flow. Corresponding one-way valves 52-1, 52-2, 52-3, arranged in parallel coolant branches, also contribute to the effectiveness of the cooling system by controlling the coolant flow through the respective coolant branches. Control over the coolant distribution, in turn, allows individual battery modules to have separate temperature settings, rather than, for example, unusual conditions within a single battery module forcing a coolant flow and / or temperature setting across the entire RESS.

Claims

Multi-cell rechargeable energy storage system, RESS, (24) comprising: a plurality of battery cells (28) arranged in individual battery modules (30-1, 30-2, 30-3); and a cooling system (36) comprising: a main coolant circuit (38) configured to circulate a coolant (40); a plurality of coolant branches (44-1, 44-2, 44-3) arranged in parallel, each coolant branch (44-1, 44-2, 44-3) being configured to receive a portion of the coolant (40) from the main coolant circuit (38) to remove thermal energy from one of the corresponding battery modules (30-1, 30-2, 30-3); and at least one flow valve (50) configured to regulate the coolant (40) circulating through the main coolant circuit (38) and to distribute it to the multitude of coolant branches (44-1, 44-2, 44-3);wherein each coolant branch (44-1, 44-2, 44-3) contains a one-way valve (52-1, 52-2, 52-3) configured to control the flow of coolant (40) from the coolant branch (44-1, 44-2, 44-3) in question. Multi-cell rechargeable energy storage system (24) according to claim 1, wherein the at least one flow valve (50) is a multi-way valve arrangement arranged in a connection between the main coolant circuit (38) and the plurality of coolant branches (44-1, 44-2, 44-3) and configured to control a flow of the coolant (40) into each of the coolant branches (44-1, 44-2, 44-3). Multi-cell rechargeable energy storage system (24) according to claim 1, wherein the at least one flow valve (50) is a plurality of throttle valves (50-1, 50-2, 50-3), each throttle valve (50-1, 50-2, 50-3) being arranged in one of the plurality of coolant branches (44-1, 44-2, 44-3) upstream of the corresponding battery module (30-1, 30-2, 30-3) and configured to control a flow of the coolant (40) into the coolant branch (44-1, 44-2, 44-3) in question. Multi-cell rechargeable energy storage system (24) according to claim 1, wherein the cooling system (36) additionally comprises a fluid pump (42) configured to circulate the coolant (40) through the main coolant circuit (38). Multi-cell rechargeable energy storage system (24) according to claim 4, wherein the cooling system (36) additionally includes a coolant cooler (54-1) configured to remove thermal energy from the coolant (40) in the main coolant circuit (38). Multi-cell rechargeable energy storage system (24) according to claim 5, wherein the cooling system (36) additionally comprises a coolant heater (54-2) configured to supply thermal energy to the coolant (40) in the main coolant circuit (38). Multi-cell rechargeable energy storage system (24) according to claim 6, further comprising an electronic control (56) configured to regulate the operation of the at least one flow valve (50), the fluid pump (42), the coolant cooler (54-1) and the coolant heater (54-2). Multi-cell rechargeable energy storage system (24) according to claim 7, wherein the electronic control (56) is additionally configured to regulate the temperature of the individual battery modules (30-1, 30-2, 30-3) by distributing the coolant (40) via the at least one flow valve (50) to the plurality of coolant branches (44-1, 44-2, 44-3). Motor vehicle (10), comprising: an electric motor-generator (14) configured to generate torque; a multi-cell rechargeable energy storage system, RESS, (24) configured to supply electrical energy to the electric motor-generator (14), the RESS (24) comprising: a plurality of battery cells (28) arranged in individual battery modules (30-1, 30-2, 30-3); and a cooling system (36) comprising: a main coolant circuit (38) configured to circulate a coolant (40); a plurality of parallel coolant branches (44-1, 44-2, 44-3), each coolant branch (44-1, 44-2, 44-3) being configured to receive a portion of the coolant (40) from the main coolant circuit (38) to remove thermal energy from one of the respective battery modules (30-1, 30-2, 30-3);and at least one flow valve (50) configured to regulate the coolant (40) circulating through the main coolant circuit (38) and to distribute it to the plurality of coolant branches (44-1, 44-2, 44-3); and an electronic control (56) configured to regulate the operation of the at least one flow valve (50); wherein each coolant branch (44-1, 44-2, 44-3) includes a one-way valve (52-1, 52-2, 52-3) configured to control the flow of the coolant (40) from the coolant branch (44-1, 44-2, 44-3) in question.

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