Vehicle comprising a battery and means for determining a maximum allowable power for the battery, and corresponding method
An automotive vehicle with electric or hybrid propulsion including a rechargeable electric accumulation battery and a braking system allowing recovery of energy, the battery being rechargeable during braking phases and during charging phases under control of a supply system including a mechanism determining a maximum allowable power for the battery. The mechanism determining the maximum allowable power for the battery includes a first mapping making it possible to read a first maximum power on the basis of a temperature and of a state of charge of the battery, and a second mapping making it possible to read a second maximum power based on the temperature and of the state of charge of the battery.
1. A motor vehicle with electric or hybrid propulsion comprising:
a rechargeable electric accumulation battery;
a braking system allowing recovery of energy;
the battery being rechargeable during braking phases and during charging phases during which the vehicle is stationary under control of a power supply system comprising means for determining a maximum allowable power for the battery, the means for determining the maximum allowable power for the battery comprises a first mapping including a first maximum power on the basis of temperature and state of charge of the battery and a second mapping including a second maximum power on the basis of the temperature and state of charge of the battery, the first maximum power being greater than the second maximum power, the first mapping comprising first maximum power values corresponding to a braking phase and the second mapping comprising second maximum power values corresponding to a charging phase of the battery; and
means for calculating the maximum allowable power for the battery, the means configured to calculate the sum of the first maximum power affected by a first coefficient α(t) between 0 and 1 and of the second maximum power affected by a second coefficient equal to 1−α(t).
2. The vehicle as claimed in claim 1 , further comprising means for measuring current circulating in the battery and means for instantaneously calculating the first coefficient α(t) giving:
a first coefficient value equal to one during the start-up of the vehicle,
an increased first coefficient value if the measured current circulating in the battery is negative,
a decreased first coefficient value if the measured current circulating in the battery is greater than a current threshold, or
an increased first coefficient value if the current circulating in the battery is between zero and the current threshold and the first coefficient was increased at a previous time point or a decreased first coefficient value if the current circulating in the battery is between zero and the current threshold and the first coefficient was decreased at the previous time point.
3. The vehicle as claimed in claim 1 , further comprising means for measuring average power provided to the battery during a period and means for instantaneously calculating the first coefficient α(t), giving:
a first coefficient value equal to one during start-up of the vehicle,
an increased first coefficient value if the average power is lower than the second maximum power value, or
a decreased first coefficient value if the average power is greater than the second maximum power value.
4. The vehicle according to claim 1 , wherein the battery is formed of one or more cells, the system comprising means for measuring a voltage at terminals of one cell and additional means for limiting the maximum allowable power for the battery providing a third maximum power value calculated depending on a maximum voltage value and the measured voltage of the cell.
5. A method for regulating charging of a rechargeable electric accumulation battery for a motor vehicle with electric or hybrid propulsion including a braking system allowing recovery of energy, the battery being rechargeable during braking phases and during charging phases during which the vehicle is stationary, the method comprising:
determining a first maximum power value corresponding to a braking phase;
determining a second maximum power corresponding to a charging phase of the battery, the first maximum power being greater than the second maximum power;
adding together the first maximum power affected by a first coefficient α(t) between 0 and 1 and the second maximum power affected by a second coefficient 1−α(t) to deduce from this the maximum allowable power for the battery; and
limiting the charging of the battery to the maximum allowable power for the battery in order to prevent damaging the battery.
6. The method as claimed in claim 5 , wherein the current circulating in the battery is measured and the first coefficient α(t) is fixed instantaneously, equal to:
one during start-up of the vehicle,
an increased first coefficient value if the measured current circulating in the battery is negative,
a decreased first coefficient value if the measured current circulating in the battery is greater than a current threshold, or
an increased first coefficient value if the current circulating in the battery is between zero and the current threshold and the first coefficient was increased at a previous time point or a decreased first coefficient value if the current circulating in the battery is between zero and the current threshold and the first coefficient was decreased at the previous time point.
7. The method as claimed in claim 5 , wherein the average power provided to the battery during a period is measured and the first coefficient α(t) is fixed instantaneously, equal to:
one during start-up of the vehicle,
an increased first coefficient value if the average power is lower than the second maximum power value, or
a decreased first coefficient value if the average power is greater than the second maximum power value.
8. The method as claimed in claim 5 , wherein the battery is formed of one or more cells, and a voltage at terminals of one cell is measured, the maximum allowable power for the battery additionally being limited on the basis of a third maximum power value calculated depending on a maximum voltage value and the measured voltage of the cell.
9. The vehicle according to claim 2 , wherein the battery is formed of one or more cells, the system comprising means for measuring a voltage at terminals of one cell and additional means for limiting the maximum allowable power for the battery providing a third maximum power value calculated depending on a maximum voltage value and the measured voltage of the cell.
10. The vehicle according to claim 3 , wherein the battery is formed of one or more cells, the system comprising means for measuring a voltage at terminals of one cell and additional means for limiting the maximum allowable power for the battery providing a third maximum power value calculated depending on a maximum voltage value and the measured voltage of the cell.
11. The method as claimed in claim 6 , wherein the battery is formed of one or more cells, and a voltage at terminals of one cell is measured, the maximum allowable power for the battery additionally being limited on the basis of a third maximum power value calculated depending on a maximum voltage value and the measured voltage of the cell.
12. The method as claimed in claim 7 , wherein the battery is formed of one or more cells, and a voltage at terminals of one cell is measured, the maximum allowable power for the battery additionally being limited on the basis of a third maximum power value calculated depending on a maximum voltage value and the measured voltage of the cell.