Battery management systems and methods

Abstract

Aspects of the present invention relate to a battery management system (104) for a battery (102) in an electric, or hybrid-electric vehicle (100), the vehicle having a first electrical circuit (310) that connects the battery to an electric drive unit, EDU, (312) of the vehicle, and a second electrical circuit (302) that connects a second load (304) to the battery. The battery management system is configured: in response to a first operational condition of the vehicle, to send a first control message to a first actuator (308) used to open the first electrical circuit and disconnect it from the battery, the control message comprising a first instruction to set a response time of the first actuator.

Description

[0001] BATTERY MANAGEMENT SYSTEMS AND METHODS

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a battery management system, a method performed by a battery management system and a vehicle comprising a battery management system, in an electric, or hybrid-electric vehicle.

[0004] BACKGROUND

[0005] Electric and hybrid-electric vehicles have batteries that are used to power the electric drive units (EDUs) of such vehicles. The vehicle battery can also be used to power other electronic systems, such as the air conditioning system, the entertainment system, and systems for powering electric windows and doors, amongst others.

[0006] SUMMARY OF THE INVENTION

[0007] Aspects and embodiments of the invention provide a battery management system for a battery in an electric or electric-hybrid vehicle, a vehicle comprising a battery management system, and a method in a battery management system, as claimed in the appended claims.

[0008] According to an aspect of the present invention there is provided a battery management system for a battery in an electric, or hybrid-electric vehicle. The vehicle has a first electrical circuit that connects the battery to an electric drive unit (EDU) of the vehicle, and a second electrical circuit that connects a second load to the battery. The battery management system is configured, in response to a first operational condition of the vehicle, to send a first control message to a first actuator used to open the first electrical circuit and disconnect it from the battery, the control message comprising a first instruction to set a response time of the first actuator.

[0009] Thus, in embodiments herein, the battery management system dynamically controls the response time of an actuator used to disconnect the EDU from the battery. In embodiments herein, for example, faster response times are set under operational conditions where the EDU is being charged using a single phase charger, compared to operational conditions in which the vehicle is in motion. Thus, while in motion, short-circuits in the second electrical circuit do not disable the EDU, while also being fast enough to protect the battery and electricity supply while the vehicle is being charged.

[0010] In some embodiments, the first instruction sets the response time of the first actuator to be greater than a response time of a second actuator used to open the second electrical circuit and disconnect the battery from the second load. Thus, different response times can be set according to the load.

[0011] In some embodiments, the first control message instructs the first actuator to set the response time of the first actuator to be greater than 850 micro-seconds. In some embodiments, the first operational condition is the vehicle having been put into a drive-mode or a reverse-mode. This allows the response time of the first actuator to be set to be greater than the response time of the second actuator, so that if the second actuator is triggered, the current surge associated with the second actuator it doesn’t inadvertently trigger the first actuator. In some embodiments, in response to a second operational condition of the vehicle, the battery management system is configured to send a second control message to the first actuator. The second control message comprising a second instruction to set the response time of the first actuator to: a default response time; and / or to a response time less than a response time of the second actuator. Thus, in some circumstances, the response of the first actuator may be dynamically set to be less than that of the second actuator.

[0012] In some embodiments, the second operational condition is the vehicle having been put into a parked-mode, or the vehicle having been connected to a vehicle charging port. In some embodiments, the second control message instructs the first actuator to set the response time of the first actuator to be less than 850 microseconds. Thus, faster response times may be dynamically set when the vehicle is put into parked or charging mode. This enables the EDU and other systems to be quickly disconnected from the battery when charging. This can be useful if the vehicle is, for example, adapted to charge from a single-phase charge adapter.

[0013] In some embodiments, the first control message initiates a hand-shake protocol between the battery management system and the first actuator. Thus, the dynamic setting of the response time of the first actuator is auditable and it can be verified that the response time was set correctly.

[0014] According to another aspect herein there is an electric or hybrid-electric vehicle, comprising: a battery; a first electrical circuit that connects the battery to an electric drive unit, the first circuit having therein a first actuator for opening the first electrical circuit and disconnecting it from the battery; a second electrical circuit that connects a second load to the battery, the second electrical circuit having therein a second actuator for opening the second electrical circuit and disconnecting it from the battery; and the battery management system of the previous aspect. Thus, the time-scale on which the EDU is disconnected from the vehicle battery is dynamically configurable in embodiments herein, dependent on operational conditions of the vehicle. In some embodiments, the first actuator is a pyro fuse. In some embodiments, the second actuator is a thermal fuse. In some embodiments, the second load is a climate control system, entertainment system, or electrically powered mechanical feature of the vehicle.

[0015] According to another aspect there is a method performed by a battery management system of an electric or hybrid-electric vehicle, the vehicle having a first electrical circuit that connects the battery to an electric drive unit, EDU, of the vehicle, and a second electrical circuit that connects a second load to the battery. The method comprises: in response to a first operational condition of the vehicle, sending a first control message to a first actuator used to open a first electrical circuit and disconnect it from the battery, the first control message comprising a first instruction to set a response time of the first actuator.

[0016] In some embodiments, the first operational condition is the vehicle having been put into a drive-mode or a reverse-mode and / or the first instruction sets the response time of the first actuator to be greater than a response time of a second actuator used to open a second electrical circuit and disconnect the battery from a second load. Thus, in a drive mode, a current surge due to the second actuator being activated can be prevented from triggering the first actuator.

[0017] In some embodiments, the method further comprises: in response to a second operational condition of the vehicle, sending a second control message to the first actuator, the second control message comprising a second instruction to set the response time of the first actuator to: a default response time; and / or to a response time less than a response time of the second actuator. Thus, fast activation of the first actuator can be set when the vehicle is in a parked or charging mode, to protect the EDU and / or electrical grid.

[0018] The battery management system comprises one or more controllers collectively comprising at least one electronic processor having an electrical input for receiving an input signal; and at least one memory device electrically coupled to the at least one electronic processor and having instructions stored therein; and wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon so as to: in response to a first operational condition of the vehicle, send a first control message to a first actuator used to open the first electrical circuit and disconnect it from the battery, the control message comprising a first instruction to set a response time of the first actuator.

[0019] Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner.

[0020] BRIEF DESCRIPTION OF THE DRAWINGS

[0021] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0022] Figure 1 shows an example vehicle having a battery and a battery management system according to some embodiments herein;

[0023] Figure 2 shows a battery management system according to some embodiments herein;

[0024] Figure 3 shows various circuits in a vehicle according to some embodiments herein; and

[0025] Figure 4 shows a method performed by a battery management system of a vehicle in accordance with some embodiments herein.

[0026] DETAILED DESCRIPTION

[0027] Embodiments herein relate to electric and hybrid-electric vehicles. Such vehicles have batteries that power the electric drive unit (EDU) as well as other electric powered features such as the air-conditioning system, the entertainment system and other features such as electric windows and electric doors. A vehicle 100 in accordance with an embodiment of the present invention is described herein with reference to Figure 1. As noted above, the vehicle 100 is an electric or hybrid-electric vehicle. For example, in some embodiments, the vehicle 100 may be plug-in electric, or plug-in hybrid-electric vehicle.

[0028] In some embodiments, the vehicle may be adapted to charge from a single high current voltage connection at the vehicle charging inlet, e.g. for both Direct Current (DC) and Alternating Current (AC) charging. In such embodiments, faster fault clearing times can be used to avoid mixing of DC an AC when charging.

[0029] Although a passenger vehicle e.g. a car is illustrated in Figure 1 , it will be appreciated that the vehicle may be any other type of electric or hybrid electric vehicle, for example, such as a lorry, van, scooter, bus, or coach.

[0030] The vehicle 100 has a battery 102 and a battery management system 104. The battery management system 104 is in wired or wireless communication with (e.g. can send instructions to) the battery 102. As illustrated in Figure 2, the battery management system 104 comprises processing means 120 and memory means 130. The processing means 120 may be one or more electronic processing device 120 which operably executes computer-readable instructions. The memory means 130 may be one or more memory device 130. The memory means 130 is electrically coupled to the processing means 120. The memory means 130 is configured to store instructions, and the processing means 120 is configured to access the memory means 130 and execute the instructions stored thereon.

[0031] The battery management system 104 comprises an input means 140 and an output means 150. The input 140 is arranged to receive signals 160 (e.g. messages or instructions) from other systems, the battery 102 and / or one or more sensors in the vehicle 100. The output 150 is arranged to output a control signal 180 to the battery and / or to the first and / or second actuators described below.

[0032] Figure 3 shows an electrical circuit 300 in a vehicle such as the vehicle 100. In this example, the electrical circuit has a battery 102 comprising two battery cells. The battery is managed by a battery management system 104. There is a first electrical circuit 310 that connects the battery 102 to the Electric Drive Unit (EDU) 312. The EDU 312 may be referred to herein as the “first load”. There is also a second electrical circuit 302 that connects the battery 102 to a second load 304. The second load may be any other electrical components in the vehicle, including but not limited to the examples described above, e.g. an air-conditioning system, electrically heated windows, heated seats / steering wheel, an entertainment system or any other electrically powered mechanical feature of the vehicle, e.g. such as electric windows, electronic seat adjustment, electric doors, electric windscreen wipers etc. It will be appreciated that in some embodiments there may be third and / or subsequent circuits 302n connecting third and / or subsequent loads 304n to the battery 102. In some embodiments, there may be a circuit for each electrical load in the vehicle.

[0033] Actuators are used to open the respective circuits and disconnect them from the battery. A first actuator 308 may be configured to disconnect the EDU (e.g. the first load) from the battery. The first actuator may be a safety-critical actuator or fuse. For example, the first actuator may be a pyro fuse. The skilled person will be familiar with pyro fuses, which are very quick mechanisms to physically open a circuit in safety-critical scenarios (e.g. where the EDU needs to be stopped).

[0034] In some examples, as illustrated in Figure 3, the first actuator may disconnect the EDU 312 as well as the second and / or third and subsequent loads 304, 304n from the battery. In some embodiments, the first actuator may disconnect the battery from all electrical loads that it is connected to.

[0035] The methods herein protect against short-circuiting across the battery. The first actuator has a response time. The response time is a “trigger” time. The response time is a threshold time interval during which, if the electrical current is over a threshold current level, the first actuator will open the first electrical circuit. In certain scenarios, such as when the vehicle is being charged, a very quick response time is needed for the first actuator. This is to protect against short circuiting across the battery and also to protect the electrical grid. Furthermore, fast actuation times may be appropriate (or mandated for compatibility reasons) in scenarios where a single-phase adapter is used to connect the vehicle to the electricity supply (e.g. the grid). For example, when the vehicle is charging, the first actuator may need to have a response time of less than about 800ps. For example, the response time may be between about 750ps and about 850ps.

[0036] The response time of the first actuator may be configurable, e.g. it may be set in response to receiving a control system. For example, the actuator of a pyro fuse may have a first ‘default’ setting of < 800ps and a higher setting of ~850 ps. The response time of the first actuator may also be set (e.g. to a bespoke level) through an API interface.

[0037] Ordinarily, the response time of the first actuator is set in a configuration process (e.g. as part of the vehicle’s manufacturing process.) In embodiments herein, the response time is changed while the vehicle is in use, e.g. in response to operational conditions of the vehicle, as described below.

[0038] A second actuator 306 may open the second circuit and disconnect the second load 304 from the battery. Similarly, third 306n and subsequent actuators may disconnect the third load 304n from the battery. The second actuator 306 and any subsequent actuators 306n may be different types of fuses to the first actuator. For example, the second actuator and / or the third and subsequent actuators 306n may be thermal fuses. The skilled person will be familiar with thermal fuses which are suitable for non-safety-critical scenarios. As such, the second and / or third and subsequent actuators may be non-safety critical fuses.

[0039] Although in some scenarios (e.g. such as when the vehicle is being charged with a single-phase adapter, as described above), the response time of the first actuator needs to be shorter (e.g. the first actuator needs to open the circuit faster) than the response time of the second and / orthird and subsequent actuators. However, in other scenarios, such as when the vehicle is in motion and being moved by the EDU, the response time of the first actuator needs to be longer (e.g. detect a current surge for a longer period of time before opening the circuit) than the response time of the second and / or subsequent actuators. For example, in embodiments where the second actuator is a thermal fuse, if the thermal fuse is triggered, it causes a current surge in the circuit. If the response time of the first actuator is less than the duration of the current surge caused by the thermal fuse, then this could trigger the first actuator. This could lead to scenarios where the EDU is disabled due to an electrical fault in the second load.

[0040] Thus, in embodiments herein, the response time of the first actuator is changed, depending on an operational condition of the vehicle. E.g. depending on an operational condition of the vehicle being satisfied, detected or initiated.

[0041] The operational condition of the vehicle may be a drive-condition of the vehicle. For example, the first operational condition may be the vehicle having been put into a drive-mode or a reverse-mode. If such a condition is detected, then the battery management system may be configured to send in the first control message, an instruction to set the response time of the first actuator to be greater than the response time of the second actuator used to open the second electrical circuit and disconnect the battery from a second load. For example, the first control message may instruct the first actuator to set the response time of the first actuator to be greater than 850 micro-seconds.

[0042] As another example, in response to a second operational condition of the vehicle, the battery management system may be configured to send a second control message to the first actuator, the second control message comprising a second instruction to set the response time of the first actuator. The second control message may set the response time of the first actuator to a default response time; and / or to a response time less than a response time of the second actuator. The second operational condition of the vehicle may be, for example, a drive-condition, e.g. such as that the vehicle has been put into a parked-mode or is otherwise stationary. In other examples, the second operational condition may be related to the charging status of the battery. For example, the second operational condition may be that the battery is being charged (e.g. that the vehicle has been connected to an electricity supply or vehicle charging port for charging). As another example, the second operational condition may be that the battery is being charged on a singlephase power supply (e.g. that the vehicle has been connected to a single-phase electricity supply or vehicle charging port for charging).

[0043] In some embodiments, the second control message may instruct the first actuator to set the response time of the first actuator to be less than 850 micro-seconds. This can quickly protect the battery and / or electric grid for example, when the charging using a single-phase charging adapter.

[0044] It will be appreciated that different control messages may be sent sequentially over a period of time, in response to the operational conditions of the vehicle changing and new operational conditions being detected.

[0045] Furthermore, the first and / or second control messages may initiate a hand-shake protocol between the battery management system and the first actuator. This enables the battery management system to verify that the requested response time has been implemented by the first actuator, ensuring audibility of the process. Figure 4 illustrates a method 400 according to an embodiment of the invention. The method 400 is a method performed by a battery management system 104 of an electric or hybrid-electric vehicle 100. The method 400 may be performed by a battery management system 104 of a vehicle such as the vehicle 100 illustrated in Figure 1 . In some embodiments, the memory 130 may comprise computer-readable instructions which, when executed by the processor 120, perform the method 400 according to an embodiment of the invention.

[0046] In a first step, the method 400 comprises, in response to a first operational condition of the vehicle, sending a first control message to a first actuator used to open a first electrical circuit and disconnect it from the battery, the control message comprising a first instruction to set a response time of the first actuator.

[0047] As described above, the first operational condition may be the vehicle having been put into a drive-mode or a reverse-mode. The first instruction may set the response time of the first actuator to be greater than a response time of a second actuator used to open a second electrical circuit and disconnect the battery from a second load.

[0048] In response to a second operational condition of the vehicle, the method may further comprise sending a second control message to the first actuator, the second control message comprising a second instruction to set the response time of the first actuator to: a default response time; and / or to a response time less than a response time of the second actuator.

[0049] The first and second operational conditions of the battery, the first and second control messages and the first and second instructions were described above with respect to the battery management system and the detail therein will be understood to apply equally to the method 400.

[0050] It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Claims

CLAIMS1 . A battery management system for a battery in an electric, or hybrid-electric vehicle, the vehicle having a first electrical circuit that connects the battery to an electric drive unit, EDU, of the vehicle, and a second electrical circuit that connects a second load to the battery, the battery management system being configured: in response to a first operational condition of the vehicle, to send a first control message to a first actuator used to open the first electrical circuit and disconnect it from the battery, the control message comprising a first instruction to set a response time of the first actuator.

2. The battery management system of claim 1 wherein the first instruction sets the response time of the first actuator to be greater than a response time of a second actuator used to open the second electrical circuit and disconnect the battery from the second load.

3. The battery management system of claim 1 or 2 wherein the first control message instructs the first actuator to set the response time of the first actuator to be greater than 850 micro-seconds.

4. The battery management system of claim 1 , 2 or 3 wherein the first operational condition is the vehicle having been put into a drive-mode or a reverse-mode.

5. The battery management system of claim 1 , 2, 3 or 4 further configured to: in response to a second operational condition of the vehicle, send a second control message to the first actuator, the second control message comprising a second instruction to set the response time of the first actuator to: a default response time; and / or to a response time less than a response time of the second actuator.

6. The battery management system of claim 5 wherein the second operational condition is the vehicle having been put into a parked-mode, or the vehicle having been connected to a vehicle charging port.

7. The battery management system of claim 5 or 6 wherein the second control message instructs the first actuator to set the response time of the first actuator to be less than 850 micro-seconds.

8. The battery management system of any one of the preceding claims wherein the first control message initiates a hand-shake protocol between the battery management system and the first actuator.

9. An electric or hybrid-electric vehicle, comprising: a battery; a first electrical circuit that connects the battery to an electric drive unit, the first circuit having therein a first actuator for opening the first electrical circuit and disconnecting it from the battery;8a second electrical circuit that connects a second load to the battery, the second electrical circuit having therein a second actuator for opening the second electrical circuit and disconnecting it from the battery; and the battery management system of any one of claims 1 to 8.

10. The electric or hybrid-electric vehicle of claim 9 wherein the first actuator is a pyro fuse.11 . The electric or hybrid-electric vehicle of claim 9 or 10 wherein the second actuator is a thermal fuse.

12. The electric or hybrid-electric vehicle of claim 9, 10 or 11 wherein the second load is a climate control system, entertainment system, or electrically powered mechanical feature of the vehicle.

13. A method performed by a battery management system of an electric or hybrid-electric vehicle, the vehicle having a first electrical circuit that connects the battery to an electric drive unit, EDU, of the vehicle, and a second electrical circuit that connects a second load to the battery, the method comprising: in response to a first operational condition of the vehicle, sending a first control message to a first actuator used to open a first electrical circuit and disconnect it from the battery, the first control message comprising a first instruction to set a response time of the first actuator.

14. The method of claim 13 wherein the first operational condition is the vehicle having been put into a drive-mode or a reverse-mode and / or the first instruction sets the response time of the first actuator to be greater than a response time of a second actuator used to open a second electrical circuit and disconnect the battery from a second load.

15. The method of claim 14 wherein the method further comprises: in response to a second operational condition of the vehicle, sending a second control message to the first actuator, the second control message comprising a second instruction to set the response time of the first actuator to: a default response time; and / or to a response time less than a response time of the second actuator.

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