Adaptive thermal management of an electric energy storage method and system apparatus

• US 9,827,871 B2
• Filed: 09/24/2013
• Issued: 11/28/2017
• Est. Priority Date: 09/24/2012
• Status: Active Grant

• Current Assignee: Robert Del Core
• Original Assignee: Robert Del Core
• Inventors: Del Core, Robert
• Primary Examiner(s): Rodas, Richard Isla
• Assistant Examiner(s): Bui, Dung V
• Application Number:
  US14/035,482
• Publication Number:
  US 20140091772A1
• Time in Patent Office: 1,526 Days
• Field of Search: 320136
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2240/662 Temperature
• CPC Class Codes: B60L 58/26 by cooling
• CPC Class Codes: B60L 58/27 by heating
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

A system, method, and computer-readable storage medium to dynamically manage heat in an electric energy storage system, such as a battery pack or ultra-capacitor pack system in an electric vehicle.

Claims

1. A thermally managed energy storage system for an electric vehicle, the electric vehicle including an overall system controller of the electric vehicle, the thermally managed energy storage system for the electric vehicle comprising:

an electric energy storage system including at least one energy storage module having a plurality of energy storage cells, the electric energy storage system configured to electrically couple to and power an electric load of the electric vehicle;

a plurality of thermal sensors configured to determine a cell temperature of at least one of the plurality of energy storage cells;

a thermal management system for regulation of operating temperature of the at least one cell within limits prescribed by a battery manufacturer, the thermal management system including a heat exchanger, a pump, and a pipe system fluidly coupled together as a closed thermal loop, the thermal management system configured to thermally condition the plurality of energy storage cells by circulating a fluid through the electric energy storage system, in response to a thermal control signal; and

a thermal management control unit configured

to receive an input signal indicative of current being supplied from the electric energy storage system to the electric load,

to receive an input signal indicative of a cell temperature of the at least one cell, the cell temperature to be used in operation of the thermal management system,

to receive an input signal indicative of ambient temperature in which the electric energy storage system is operated for operation of the thermal management system,

to receive an input signal from a vehicle control device, the input signal from the vehicle control device including a request for current to be supplied from the electric energy storage system at a specific time, at a specified current,

to output to the overall system controller of the electric vehicle a signal representing an allowable current to be supplied from the electric energy storage system to the electric load,

to compute an averaged current from the energy storage system,

to compute a partial differential transient heat equation for the generation of cell temperature control signals, and

to issue a command to the overall system controller of the electric vehicle to heat or cool the electric energy storage system via the thermal management system, and responsive to the averaged current from the energy storage system, and the partial differential transient heat equation for the generation of cell temperature control signals.

2. The thermally managed energy storage system of claim 1, wherein the input and output signals are discrete.

3. The thermally managed energy storage system of claim 2, wherein the thermally managed energy storage system is connectable to an existing communication control network without modification of other devices on that control network.

4. The thermally managed energy storage system of claim 1, further comprising a storage device to store a computed value to be used in calculating a temperature setpoint.

5. The thermally managed energy storage system of claim 1, further comprising an actuator in the form of a dry contact, a PWM signal generator, or a relay center, which interfaces to a vehicle HVAC system and is configured to command the vehicle HVAC system.

6. The thermally managed energy storage system of claim 1, wherein the temperature setpoint is determined by the control expression

t_set_point=t_setpoint_max−

M*((I_AVG*α

+(1−

α

)*I_CDR)²*R_internal/(A*(I_AVG*α

+(1−

α

)*I_CDR)^B*Acell))

where,

t_set_point is the temperature setpoint;

t_setpoint_max is a maximum setpoint of the vehicle HVAC system;

M is a parameter determined by a mapping function that maps an allowable temperature rise between the maximum and minimum temperature set points;

I_AVG is an average current of a battery duty cycle;

I_CDR is a requested current;

α

is a weight parameter;

R_internal is battery internal resistance;

A is a cross sectional area of a battery cell; and

,

B is a width of the battery cell.

7. The thermally managed energy storage system of claim 6, wherein the mapping function includes a linear function.

8. The thermally managed energy storage system of claim 6, wherein the mapping function includes a higher order polynomial function.

9. The thermally managed energy storage system of claim 6, wherein I_AVG is computed using a time average value of actual current the electrical energy storage system is delivering over a tunable preset time interval.

10. The thermally managed energy storage system of claim 6, wherein the function in the form of Kα

+(1−

α

)K is used to weight the average current and the requested current to compute a weighted average current with weight α

, such that α

is a number between 0 and 1.

11. The thermally managed energy storage system of claim 10, wherein α

is a function of the energy storage state of charge or α

=1−

SOC.

12. The thermally managed energy storage system of claim 6, wherein temperature rise for generating time dependent boundary conditions for a 1-dimensional numerical model of a battery and cell and surrounding structure is given by a temperature rise relation I²R/AI^BAcell, where I(t) @ t=t+dt is found by interpolation between current request points I(t) @ t=t and I(t) @ t=t+dt.

13. The thermally managed energy storage system of claim 12, wherein a one dimensional time dependent partial differential heat equation is numerically solved to obtain a virtual average cell temperature using a 1-dimensional model of the cell, thus reducing the number of required sensors in a battery array.

14. The thermally managed energy storage system of claim 13, wherein a partial differential equation solution is compared with T_Actual to determine cells are within temperature limits, and issue a current rate to some pre-set value determine by the invention.

15. The thermally managed energy storage system of claim 14, wherein tcell and tpde are compared to determine SOH as time progresses, issuing a diagnostic message if the difference grows beyond bound.

16. The thermally managed energy storage system of claim 15, wherein the energy storage system and thermal management system are included in the electric vehicle.

17. The thermally managed energy storage system of claim 16, wherein the thermal management control unit is included in the overall system controller of the electric vehicle.

18. The thermally managed energy storage system of claim 16, wherein the thermal management control unit is a standalone device but included in the electric vehicle.

19. The thermally managed energy storage system of claim 16, wherein the thermal management control unit includes a high performance numerical computation unit.