A battery energy storage system and a related method

Abstract

The disclosure relates to a battery energy storage system (1), comprising one or more battery modules (3), each module holding a plurality of battery cells (4). The system further comprises an enclosure (2) housing said battery modules (3), and one or more igniters (5) configured to produce a spark when activated. Notably, the igniter (5) is provided within the enclosure (2) and is further configured suitable to ignite a combustible gaseous mixture within the enclosure (2) resulting from gas venting of one or more of the battery modules (3). The disclosure further concerns a method of preventing build-up of a combustible gaseous mixture resulting from gas venting from one or more battery modules (3) in a battery energy storage system (1).

Description

[0001] A BATTERY ENERGY STORAGE SYSTEM AND A RELATED METHOD

[0002] FIELD OF THE DISCLOSURE

[0003] The present disclosure relates to battery energy storage systems. The present disclosure further concerns a method for preventing build-up of a combustible gaseous mixture resulting from gas venting.

[0004] BACKGROUND OF THE DISCLOSURE

[0005] In conventional battery energy storage systems, multiple battery cells are provided within a battery module for storing electrical power. A plurality of such modules are typically placed one above another as a rack, and multiple such racks are provided one next to another within a battery unit or enclosure. Furthermore, multiple such units or enclosures may be coupled to form the battery capacity of the system.

[0006] In case of a malfunction or damage, a battery cell may undergo gas venting, in which a flammable gaseous mixture is released from the battery cell. On rare occasion this gaseous mixture may ignite and cause a deflagration event. Uncontrolled, this deflagration may propagate to other battery cells, modules, racks or even units.

[0007] A conventional approach of preventing propagation of the deflagration has been e.g., to pre-emptively ventilate the gaseous mixture from the enclosure. Such ventilation both consumes energy and also requires periodic maintenance to ensure proper operation.

[0008] BRIEF DESCRIPTION OF THE DISCLOSURE

[0009] An object of the present disclosure is to provide a battery energy storage system and a method achieving a simple and robust solution for preventing build-up of a combustible gaseous mixture resulting from gas venting.

[0010] The object of the disclosure is achieved by a battery energy storage system and a method which are characterized by what is stated in the independent claims. The preferred embodiments of the disclosure are disclosed in the dependent claims.

[0011] According to a first aspect of the present disclosure, a battery energy storage system, comprising one or more battery modules, is provided. The battery energy storage system further comprises an enclosure housing said battery modules, while each battery module holds a plurality of battery cells, suitably within a casing of a respective battery module.

[0012] Particularly, the battery energy storage system further comprises one or more igniters. The igniter is configured to produce a spark when activated. For example, the igniter may be provided as a spark generator having a pair of electrodes closely spaced apart from each, such that a spark is generated between the electrodes when the electrodes are suspected to an electrical potential difference.

[0013] Moreover, the igniter is provided within the enclosure of the battery energy storage system and is further configured suitable to ignite a combustible gaseous mixture within the enclosure. That is, the igniter is configured to produce sparking within the casing. Notably, in the context of this disclosure, the combustible gaseous mixture is used for describing a combustible gaseous mixture resulting from gas venting from one or more of the battery cells.

[0014] In an embodiment according to the first aspect of present disclosure, the battery energy storage system comprises an ignition control unit operationally coupled to the one or more igniters. For example, the ignition control unit may be provided as a separate control unit, or it may alternatively be integrated with the battery management system of the battery energy system.

[0015] The ignition control unit may be configured to activate the igniter periodically, for example at pre-determined intervals. In another example, the ignition control unit may be configured to activate the igniter in response to manual input, i.e. upon operator input. In a further example, the ignition control unit may be configured to activate the igniter in response to a gas detector signal indicative of gas venting from one or more of the battery cells. Such a gas detector may produce a signal indicating a presence or concentration of a combustible gaseous mixture within the casing, resulting from gas venting from one or more battery cells.

[0016] The provision of a gas detector as discussed above can be carried out in a multitude of different ways. For example, the increase (within the casing) of one or more of temperature, light intensity, humidity, CO concentration, CO2concentration, H2concentration, heat flux, motion, acoustic signal(s) and pressure may be used for determining a presence or concentration of a combustible gaseous mixture within the casing, resulting from gas venting from one or more battery cells. Alternatively, or in addition, a decrease of 02 concentration or an optical signal(s) may be used for determining a presence or concentration of a combustible gaseous mixture within the casing, resulting from gas venting from one or more battery cells.

[0017] Moreover, the ignition control unit may be configured to operate according to more than one control mode, as discussed above, or even according to combinations thereof. For example, the ignition control unit may be configured to activate the igniter periodically in response to the gas detector signal indicative of gas venting from one or more of the battery cells, such that an interval between subsequent igniter activations is determined based on the gas detector signal. That is, the ignition frequency is higher when the presence of a gaseous combustible mixture is detected within the casing, and I or the ignition frequency is increased when the concentration of the combustible gaseous mixture increases (interval between subsequent igniter activations decreases).

[0018] Preferably, but not necessarily, the battery energy system comprises a humidity sensor provided within the enclosure. The humidity sensor is operationally coupled to the ignition control unit and configured to produce a signal indicative of relative humidity prevailing within the enclosure. The ignition control unit may then be further configured to monitor relative humidity prevailing within the enclosure for detecting a peak increase in said relative humidity. For example, such a peak increase can be defined as either or both of a predetermined increase from a given base level, or a predetermined increase within a given time frame.

[0019] Upon detection of a peak increase in said relative humidity, the ignition control unit may further be configured to determine an occurrence of a combustion within the enclosure, and to generate a combustion alarm signal indicative of a combustion event within the enclosure. Such a combustion alarm may be relayed to a further control unit the battery energy storage system and I or be used as a trigger for further measures (e.g. activating extinguishing equipment, decoupling a battery module or a battery unit from the remaining system etc).

[0020] In an embodiment according to the first aspect, the battery energy storage system comprises a plurality of battery modules arranged as one or more racks, wherein each rack has multiple battery modules superimposed one above another. Preferably, at least one igniter is provided for each rack. Moreover, where multiple rack are provided, they are suitably arranges one next another within the enclosure.

[0021] In an embodiment according to first aspect of the present disclosure, the battery energy storage system comprises a venting outlet. For example, such a venting outlet may be provided as a safety vent, a pressure relief valve, a flame arrester or any combination thereof. Suitably, at least one igniter is arranged between one or more battery modules and the venting outlet. Preferably at least one igniter is arranger between all of the battery modules and the venting outlet. As such a venting outlet allows communication between an inside and an outside of the enclosure, thereby allowing a gaseous mixture from within the enclosure to flow out from the enclosure, a venting path is defined past the igniter. That is, a flow route of venting gas runs past the igniter. This, in turn, ensures that such a combustible gaseous mixture will indeed ignite before excessively building up. Preferably, but not necessarily, at least an igniter is provided above the battery modules, suitably adjacent to or at a ceiling of the enclosure.

[0022] Preferably, but not necessarily, at least an igniter being provided above at least one battery modules and below at least one battery module.

[0023] In an embodiment according to the first aspect of the disclosure, the battery energy storage system comprises a primary power interface for coupling the energy storage system to an electrical network. The primary power interface may be configured such that the battery cells can be charged from and discharged to said electrical network. Suitably, either or both of the ignition control unit and the one or more igniters are coupled to the primary power interface so as to be powered therefrom.

[0024] In an embodiment according to the first aspect of the disclosure, the battery energy storage system comprises a secondary power interface for coupling an UPS (uninterrupted power supply) -system. Suitably, the ignition control unit and I or the one or more igniters are coupled to the secondary power interface so as to be powered therefrom.

[0025] In an embodiment according to the first aspect of the disclosure, either or both the ignition control unit and the one or more igniters are coupled to at least one battery module so as to be powered therefrom.

[0026] In an embodiment according to the first aspect of the disclosure, the battery energy storage system comprises either or both of multiple superimposed battery modules one above another and multiple adjacent battery modules one next to another.

[0027] It should be noted that the second aspect of the disclosure encompasses any combination of two or more embodiments, or variants thereof, as discussed above.

[0028] According to a second aspect of the present disclosure, a method is provided for preventing build-up of a combustible gaseous mixture resulting from gas venting from one or more battery modules in a battery energy storage system.

[0029] In the method, one or more battery modules are provided, each module holding a plurality of battery cells. An enclosure housing said battery modules is also provided.

[0030] Moreover, one or more igniters are provided within the enclosure. The igniters are configured to produce a spark when activated and suitable to ignite a combustible gaseous mixture within the enclosure resulting from gas venting of one or more of the battery modules.

[0031] The igniter may be activated periodically, for example at pre-determined intervals. In another example, the igniter may be activated in response to manual input, i.e. upon operator input. In a further example, the igniter may be activated response to a gas detector signal indicative of gas venting from one or more of the battery cells. Such a gas detector may produce a signal indicating a presence or concentration of a combustible gaseous mixture within the enclosure, resulting from gas venting from one or more battery cells.

[0032] Moreover, the igniter may be activated in accordance to more than one control mode, as discussed above, or even according to combinations thereof. For example, the igniter may be activated periodically in response to the gas detector signal indicative of gas venting from one or more of the battery cells, such that an interval between subsequent igniter activations is determined based on the gas detector signal. That is, the ignition frequency is higher when the presence of a gaseous combustible mixture is detected within the enclosure, and I or the ignition frequency is increased when the concentration of the combustible gaseous mixture increases (interval between subsequent igniter activations decreases).

[0033] In an embodiment according to the second of the present disclosure, a humidity sensor may be provided. Suitably, such a humidity sensor is configured to produce a signal indicative of relative humidity prevailing within a casing of at least one battery module.

[0034] Moreover, relative humidity prevailing within the casing is monitored. Upon detection of a peak increase in said relative humidity, an occurrence of a combustion within the casing is determined. Furthermore, upon determination of a combustion within the casing, a combustion alarm signal indicative of a combustion event within the casing is produced.

[0035] Such a combustion alarm may be used as a trigger for further measures (e.g. activating extinguishing equipment, decoupling the battery module or battery unit from the remaining system etc).

[0036] It should be noted that the second aspect of the disclosure encompasses any combination of two or more embodiments, or variants thereof, as discussed above.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In the following the disclosure will be described in greater detail by means of preferred embodiments with reference to the accompanying drawings, in which

[0039] Fig. 1 schematically illustrates battery energy storage system according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE DISCLOSURE

[0040] In Fig. 1 , a battery energy storage system 1 is shown. The system 1 includes an enclosure 2 housing a plurality of battery modules 3, each module comprising a plurality of battery cells 4.

[0041] Notably, the enclosure 2 comprises a venting outlet 2a, which is located the an upper portion of an end side of the enclosure 2, near the ceiling thereof.

[0042] Moreover, Fig. 1 depicts a plurality of igniters 5. Namely, two igniters are provided at the ceiling of the enclosure, while two other igniters are provided at a position above a lowermost battery module 3 and below an uppermost battery module 3. In addition, a gas detector 7a and a humidity sensor 7b are provided. Again, in the embodiment of Fig. 1 both the gas detector 7a and the humidity sensor 7b are provided at ceiling level. As depicted with dashed lines, the igniters 5, the gas detector 7a and the humidity sensor 7b are operationally coupled to the ignition control unit.

[0043] Fig. 1 also depicts a primary power interface 8. Although not explicitly illustrates, the primary power interface 8 allows the battery cells 4 to be charged from and discharge to an electrical network 10. Moreover, the ignition control unit 6 is also coupled to the primary power interface 8, such that the ignition control unit 6 (and possibly also the igniters 7, gas detector 7a and humidity sensor 7b) can be powered by the electrical network 10.

[0044] Furthermore, the battery energy storage system 1 of Fig. 2 also comprises a secondary power interface 9. The ignition control unit 6 is also coupled to the secondary power interface 9, such that the ignition control unit 6 (and possibly also the igniters 7, gas detectors 7a and humidity sensors 7b) can be powered by an UPS (uninterrupted power supply) system 11 via the secondary power interface.

[0045] It is noted that Fig. 1 illustrates the disclosure with reference to a configuration having a certain number of entities (e.g., battery modules 3, battery cells 4, igniters 5, the gas detector 7a, and the humidity sensor 7) at certain positions. That being said, other configurations are also possible, e.g., such entities can be provided at other numbers and / or at other positions as depicted in Fig. 1 .

[0046] LIST OF REFERENCE NUMERALS

[0047] 1 battery energy storage system

[0048] 2 enclosure

[0049] 2a venting outlet

[0050] 3 battery module 4 battery cell

[0051] 5 igniter

[0052] 6 ignition control unit

[0053] 7a gas detector 7b humidity sensor

[0054] 8 primary power interface

[0055] 9 secondary power interface

[0056] 10 electrical network

[0057] 11 UPS system

Claims

CLAIMS1 . A battery energy storage system (1), comprising: one or more battery modules (3), each module holding a plurality of battery cells(4); an enclosure (2) housing said battery modules (3), and one or more igniters (5) configured to produce a spark when activated, characterized in that the igniter (5) is provided within the enclosure (2) and is further configured suitable to ignite a combustible gaseous mixture within the enclosure (2) resulting from gas venting of one or more of the battery modules (3).

2. The battery energy storage system (1) according to claim 1 , characterized in that the system further comprises an ignition control unit (6) operationally coupled to the igniter(5), wherein the ignition control unit (6) is configured to one or more of the following: activate the igniter (5) periodically;- activate the igniter (5) in response to manual input, and activate the igniter (5) in response to a gas detector (7a) signal indicative of gas venting from one or more of the battery modules (3).

3. The battery energy storage system (1) according to claim 2, characterized in that the ignition control unit (6) is configured to activate the igniter (5) periodically in response to the gas detector (7a) signal indicative of gas venting from one or more of the battery modules (3), such that an interval between subsequent igniter activations is determined based on the gas detector (7a) signal.

4. The battery energy storage system (1) according to any of the preceding claims 1-3, characterized in that the system further comprises a humidity sensor (7b) provided within the enclosure (2), wherein the humidity sensor (7b) is configured to produce a signal indicative of relative humidity prevailing within the enclosure (2), wherein the humidity sensor (7b) is operationally coupled to the ignition control unit (6), and wherein the ignition control unit (6) is further configured to:- monitor relative humidity prevailing within the enclosure (2) for detecting a peak increase in said relative humidity, and- upon detection of a peak increase in said relative humidity, determine an occurrence of a combustion within the enclosure (2), and to generate a combustion alarm signal indicative of a combustion event within the enclosure (2).

5. The battery energy storage system (1) according to any of the preceding claims 1-4, characterized by a plurality of battery modules (3) arranged as one or more racks, wherein each rack has multiple battery modules (5) superimposed one above another, and wherein at least one igniter (5) is proved for each rack.

6. The battery energy storage system (1) according to any of the preceding claims 1-5, characterized by comprising a venting outlet (2a), and wherein at least an igniter (5) being arranged between a battery module and the venting outlet.

7. The battery energy storage system (1) according to claim 6, characterized in that at least an igniter (5) being provided above the battery modules (3).

8. The battery energy storage system (1) according to claim 6 or 7, characterized in that at least an igniter (5) being provided above at least one battery modules (3) and below at least one battery module (3).

9. The battery energy storage system (1) according to any of the preceding claims 1-8, characterized by comprising a primary power interface (8) for coupling the energy storage system to an electrical network (10) such that the battery cells (4) can be charged from and discharged to said electrical network (10), wherein either or both of the ignition control unit (6) and the one or more igniters (5) are coupled to the primary power interface (8) so as to be powered therefrom.

10. The battery energy storage system (1) according to any of the preceding claims 1-9, characterized by comprising a secondary power interface (9) for coupling an UPS system, wherein either or both the ignition control unit (6) and the one or more igniters (5) are coupled to the secondary power interface (9) so as to be powered therefrom.11 . The battery energy storage system (1) according to any of the preceding claims 1-10, characterized in that either or both the ignition control unit (6) and the one or moreigniters (5) are coupled to at least one battery module (3) so as to be powered therefrom.

12. The battery energy storage system (1) according to any of the preceding claims 1-8, characterized by comprising either or both of multiple superimposed battery modules one above another and multiple adjacent battery modules one next to another.

13. A method of preventing build-up of a combustible gaseous mixture resulting from gas venting from one or more battery modules (3) in a battery energy storage system (1), comprising the steps of: providing one or more battery modules (3), each module holding a plurality of battery cells (4); providing an enclosure (2) housing said battery modules, and providing one or more igniters (5) configured to produce a spark when activated, characterized in that the igniter (5) is provided within the enclosure (2) and is further configured suitable to ignite a combustible gaseous mixture within the enclosure resulting from gas venting of one or more of the battery modules (3), and wherein the method further comprises one or more of the following steps:- activating the igniter (5) periodically;- activating the igniter (5) in response to manual input, and activating the igniter (5) in response to a gas detector (7a) signal indicative of gas venting from one or more of the battery cells (4).

14. The method according claim 13, characterized by further comprising the steps of: providing a humidity sensor (7b) configured to produce a signal indicative of relative humidity prevailing within the enclosure (2); monitoring relative humidity prevailing within the enclosure (2), and upon detection of a peak increase in said relative humidity, determining an occurrence of a combustion within the enclosure (2), and upon determination of a combustion within the enclosure (2), producing a combustion alarm signal indicative of a combustion event within the enclosure (2).

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