US 8,410,760 B2 · Battery thermal system control strategy

Abstract

A method and system for controlling temperature in an electric vehicle battery pack which preserves battery pack performance and longevity while maximizing vehicle driving range. A controller prescribes a minimum allowable operating temperature in the battery pack, where the minimum operating temperature increases as battery pack state of charge and remaining useful life decrease. During vehicle driving operations, the minimum allowable temperature is computed, and a thermal management system is used to warm the battery pack only if necessary to raise its temperature above the calculated minimum level. By minimizing use of the thermal management system to warm the battery pack, energy consumption is reduced and vehicle driving range is increased, while not adversely affecting battery pack performance or durability. The same strategy is employed during charging, which reduces the amount of energy consumed from the grid for warming the battery pack.

Claims19

Dependent claims

A method for thermal management of a battery pack, said method comprising:

determining state of charge of the battery pack and designating the state of charge most recently determined as current state of charge;
determining remaining useful life of the battery pack;
defining a minimum set point temperature for operation of the battery pack, where the minimum set point temperature is based on required battery pack performance, the state of charge of the battery pack, and the remaining useful life of the battery pack;
measuring temperature in the battery pack;
and
controlling the temperature in the battery pack to prevent the battery pack from being operated when the temperature is below the minimum set point temperature.

3 more elements

A method for thermal management of a lithium-ion battery pack in an electric vehicle, said method comprising:

determining state of charge of the battery pack and designating the state of charge most recently determined as current state of charge;
determining remaining useful life of the battery pack;
defining a first minimum set point temperature for operation of the battery pack, where the first minimum set point temperature is based on required battery pack performance, the state of charge of the battery pack, and the remaining useful life of the battery pack;
defining a second minimum set point temperature for operation of the battery pack, where the second minimum set point temperature is based on required battery pack durability, the state of charge of the battery pack, and the remaining useful life of the battery pack;
defining a maximum set point temperature for operation of the battery pack;
measuring temperature in the battery pack;
and
controlling the temperature in the battery pack based on the first minimum set point temperature, the second minimum set point temperature, and the maximum set point temperature.

5 more elements

A thermal management system for a battery pack providing electrical energy to an apparatus, said thermal management system comprising:

a plurality of sensors for measuring voltage in the battery pack and temperature in the battery pack, where the measured voltage is used to determine state of charge of the battery pack, and the state of charge last determined is designated as current state of charge;
means for determining remaining useful life of the battery pack;
a heating and cooling system for adding heat to or removing heat from the battery pack;
and
a controller for managing the temperature in the battery pack, said controller being responsive to measurement signals from the sensors and being configured to control the heating and cooling system to control the temperature in the battery pack as a function of the state of charge of the battery pack and the remaining useful life of the battery pack.

2 more elements

Dependencies are inferred from the claim text.

Battery thermal system control strategy

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Battery thermal system control strategy

Life of this patent

Abstract

Claims19