Active and passive cooling for an energy storage module

Abstract

The present disclosure relates to cooling an energy storage module using passive and active cooling techniques. Passive cooling is provided by storing heat in a phase change material that is contact with the energy storage cells of the energy storage module. Active cooling is provided by circulating coolant through coolant passages that are in thermal contact with the energy storage cells. A control system for determining the temperature of the energy storage module and controlling coolant flow when the temperature reaches a predetermined threshold is disclosed.

What is claimed is: 
     
         1 . A method for cooling an energy storage module comprising:
 determining a first temperature in an energy storage module, the energy storage module comprising:
 an array of energy storage cells; 
 a phase change material in thermal contact with a coolant passage and said energy storage cells; 
   comparing the first temperature to a first and second threshold; and   changing coolant flow through said coolant passage based on the comparison.   
     
     
         2 . The method of  claim 1  wherein the change comprises increasing coolant flow through said coolant passage when the first temperature reaches the second threshold. 
     
     
         3 . The method of  claim 1  wherein the change comprises decreasing coolant flow when the first temperature reaches the first threshold. 
     
     
         4 . The method of  claim 1  wherein the first threshold is modified based on the net electrical power flowing into or out of said energy storage module over a predetermined period of time. 
     
     
         5 . The method of  claim 2  wherein said predetermined period of time is between one and ten seconds. 
     
     
         6 . The method of  claim 1  wherein said coolant passage is incorporated within a block of said phase change material. 
     
     
         7 . The method of  claim 1  wherein said coolant passage is incorporated within a cold plate that is in thermal contact with said phase change material. 
     
     
         8 . The method of  claim 1  wherein the method further comprises:
 determining a second temperature in said energy storage module; and 
 decreasing coolant flow when the second temperature reaches the first threshold. 
 
     
     
         9 . The method of  claim 8  wherein the first threshold is modified based on the net electrical power flowing into or out of said energy storage module over a predetermined period of time. 
     
     
         10 . The method of  claim 9  wherein said predetermined period of time is. 
     
     
         11 . The method of  claim 8  wherein said coolant passage is incorporated within a block of said phase change material. 
     
     
         12 . The method of  claim 8  wherein said coolant passage is incorporated within a cold plate that is in thermal contact with said phase change material. 
     
     
         13 . The method of  claim 1  wherein the first temperature is determined by choosing the maximum of two temperatures. 
     
     
         14 . A method for cooling an energy storage module comprising:
 determining a first temperature in an energy storage module, the energy storage module comprising:
 an array of energy storage cells; 
 a phase change material in thermal contact with a coolant passage and said energy storage cells; 
   measuring a coolant temperature;   comparing the first temperature and the coolant temperature; and   taking a corrective action based on the comparison.   
     
     
         15 . The method of  claim 14  wherein the corrective action comprises increasing coolant flow through a coolant passage in the energy storage module if the coolant temperature is less than the first temperature and when the first temperature reaches a second threshold. 
     
     
         16 . The method of  claim 14  wherein the corrective action comprises decreasing coolant flow through a coolant passage in the energy storage module if the coolant temperature is less than the first temperature and when the first temperature reaches a first threshold. 
     
     
         17 . The method of  claim 14  wherein the corrective action comprises derating the performance of the energy storage module if the coolant temperature is greater than the first temperature. 
     
     
         18 . The method of  claim 15  wherein the second threshold is modified based on the net electrical power flowing into or out of said energy storage module over a predetermined period of time. 
     
     
         19 . The method of  claim 18  wherein said predetermined period of time is between one and ten seconds. 
     
     
         20 . The method of  claim 14  wherein said coolant passage is incorporated within a block of said phase change material. 
     
     
         21 . The method of  claim 14  wherein said coolant passage is incorporated within a cold plate that is in thermal contact with said phase change material. 
     
     
         22 . The method of  claim 16  wherein the corrective action further comprises:
 measuring a second temperature in said energy storage module; and 
 decreasing coolant flow when the second temperature reaches the first threshold. 
 
     
     
         23 . The method of  claim 22  wherein the first threshold is modified based on the net electrical power flowing into or out of said energy storage module over a predetermined period of time. 
     
     
         24 . A system for managing thermal conditions of an energy storage module comprising:
 a pump for providing coolant flow;   a valve configured receive signals from a controller and to control said coolant flow;   the controller configured to:
 receive a first temperature from a first temperature sensor in an energy storage module, the energy storage module comprising: 
 an array of energy storage cells; 
 a phase change material in thermal contact with a coolant passage and said energy storage cells; 
 compare the first temperature to a first and second threshold; and 
 send a signal to said valve to control coolant flow through said coolant passage based on the comparison. 
   
     
     
         25 . The method of  claim 24  wherein said coolant passage is incorporated within a block of said phase change material. 
     
     
         26 . The method of  claim 24  wherein said coolant passage is incorporated within a cold plate that is in thermal contact with said phase change material.