Method for managing the temperature of a battery of an electric or hybrid vehicle
A method for managing the temperature of a battery of an electric or hybrid vehicle includes recording a temperature value at which the cooling or heating of the battery is triggered. The method further includes, for two consecutive values in a predefined sequence of states of charge: a step of comparing a real gradient to a reference gradient of the battery temperature; and a step of modifying, depending on the comparison, the value of the trigger temperature, or the value of the power output by cooling or heating the battery; and also includes applying the modified trigger temperature or output power for the following two consecutive values of the state of charge of the battery in the predefined sequence.
1. A method for managing a temperature of a battery of an electric or hybrid vehicle, comprising:
recording in a memory a temperature value at which cooling or heating of the battery is triggered;
performing, for two consecutive values of a state of charge of the battery in a predefined sequence:
comparing a value of a real gradient of the temperature of the battery to a reference gradient of the temperature of the battery, and
modifying, depending on a result of the comparing,
the temperature value at which the cooling or the heating of the battery is triggered, or
a value of power delivered by means for cooling or heating the battery; and
applying the modified trigger temperature value or the modified delivered power value for the following two consecutive values of the state of charge of the battery in the predefined sequence,
wherein the reference gradient of the temperature of the battery is variable and is calculated when the performing is done for a first of the two consecutive values of the state of charge of the battery and then is calculated again when the performing is done for a second of the two consecutive values of the state of charge of the battery.
2. The method as claimed in claim 1 , further comprising:
initializing, including storing a value of an initial reference gradient beforehand in a map installed onboard the vehicle, or determining the value of the initial reference gradient as follows:
(
d
T
d
SOC
)
_
target
=
T
maximum_before
_derating
-
T
initial
SOC
initial
-
SOC
end_of
_discharge
With
T maximum _ before _ derating being a maximum usage temperature of the battery corresponding to the acceptable limit of discharge or regenerative braking power, beyond which available power decreases;
T initial being the temperature of the battery at a time of implementation of the initializing;
SOC initial being the state of charge of the battery at the time of implementation of the initializing; and
SOC end _ of _ discharge being the state of charge of the battery corresponding to an end of discharge or to a state of minimal charge usable by the battery.
3. The method as claimed in claim 1 , further comprising:
defining the value of the reference gradient for a state of charge value given by the equation:
(
d
T
d
SOC
)
(
i
)
_
target
=
T
maximum_before
_derating
-
T
SOC
(
i
)
SOC
(
i
)
-
SOC
end_of
_discharge
;
With
T maximum _ before _ derating being a maximum usage temperature of the battery corresponding to the acceptable limit of discharge or regenerative braking power, beyond which available power decreases;
T SOC(i) being the value of the temperature of the battery measured at the state of charge SOC(i); and
SOC end _ of _ discharge being the state of charge of the battery corresponding to an end of discharge or to a state of minimal charge usable by the battery.
4. The method as claimed in claim 1 , wherein the comparing comprises calculation of a difference E, in absolute value, between the gradient and the reference gradient between said consecutive values of the state of charge of the battery in the predefined sequence.
5. The method as claimed in claim 1 , further comprising:
determining driving type or driving manner of a driver.
6. The method as claimed in claim 4 , wherein
if E>0, a driving type is considered to be harsh; and
if E<0, the driving type is considered to be normal or gentle.
7. The method as claimed in claim 6 , further comprising:
decreasing, when the driving type is harsh, the value of the trigger temperature recorded for two consecutive values of the state of charge of the battery in a predefined sequence, and
applying the decreased value of the trigger temperature for the following two consecutive values of the state of charge of the battery in the predefined sequence.
8. The method as claimed in claim 7 , wherein a reduced value of the trigger temperature is calculated in accordance with the equation:
T
new
client
trigger
threshold
=
T
old
trigger
threshold
-
Kp
·
d
SOC
d
t
·
ɛ
with the term Kp being a constant term; and
T old trigger threshold being a value of the trigger temperature not yet reduced.
9. The method as claimed in claim 8 , further comprising:
increasing a value of a recorded threshold temperature T old trigger threshold such that the cooling of the battery is triggered later when the driving type is considered to be normal or gentle.
10. A non-transitory computer readable medium, comprising program code instructions for execution of the method as claimed in claim 1 , when said program is executed on a computer.
11. A method for managing a temperature of a battery of an electric or hybrid vehicle, comprising:
recording in a memory a temperature value at which cooling or heating of the battery is triggered;
performing, for two consecutive values of a state of charge of the battery in a predefined sequence:
comparing a value of a real gradient of the temperature of the battery to a reference gradient of the temperature of the battery, and
modifying, depending on a result of the comparing,
the temperature value at which the cooling or the heating of the battery is triggered, or
a value of power delivered by means for cooling or heating the battery;
applying the modified trigger temperature value or the modified delivered power value for the following two consecutive values of the state of charge of the battery in the predefined sequence; and
initializing, including storing the value of an initial reference gradient beforehand in a map installed onboard the vehicle, or determining the value of the initial reference gradient as follows:
(
d
T
d
SOC
)
_
target
=
T
maximum_before
_derating
-
T
initial
SOC
initial
-
SOC
end_of
_discharge
With
T maximum _ before _ derating being a maximum usage temperature of the battery corresponding to the acceptable limit of discharge or regenerative braking power, beyond which the available power decreases,
T initial being the temperature of the battery at a time of implementation of the initializing;
SOC initial being the state of charge of the battery at the time of implementation of the initializing; and
SOC end _ of _ discharge being the state of charge of the battery corresponding to the end of discharge or to the state of minimal charge usable by the battery.
12. A method for managing a temperature of a battery of an electric or hybrid vehicle, comprising:
recording in a memory a temperature value at which cooling or heating of the battery is triggered;
performing, for two consecutive values of a state of charge of the battery in a predefined sequence:
comparing a value of a real gradient of the temperature of the battery to a reference gradient of the temperature of the battery, and
modifying, depending on the result of the comparing,
the temperature value at which the cooling or the heating of the battery is triggered, or
a value of power delivered by means for cooling or heating the battery;
applying the modified trigger temperature value or the modified delivered power value for the following two consecutive values of the state of charge of the battery in the predefined sequence; and
defining the value of the reference gradient for a state of charge value given by the equation:
(
d
T
d
SOC
)
(
i
)
_
target
=
T
maximum_before
_derating
-
T
SOC
(
i
)
SOC
(
i
)
-
SOC
end_of
_discharge
;
With
T maximum _ before _ derating being a maximum usage temperature of the battery corresponding to the acceptable limit of discharge or regenerative braking power, beyond which available power decreases;
T SOC(i) being the value of the temperature of the battery measured at a state of charge SOC(i); and
SOC end _ of _ discharge being the state of charge of the battery corresponding to an end of discharge or to a state of minimal charge usable by the battery.