Method and system for cooling a device

Abstract

There is described a method ( 20 ) of cooling a device generating heat. The method includes ( 21 ) monitoring a temperature associated with the device. The method also includes ( 25 ) automatically operating a cooling means at a first rate if the monitored temperature rises above a first temperature threshold. The method also includes ( 26 ) automatically operating the cooling means at a second increased rate if the monitored temperature rises above a second temperature threshold. There is also described a system ( 10 ) for cooling a device ( 16 ) generating heat. The system ( 10 ) comprises means ( 18 ) for monitoring a temperature associated with the device ( 10 ), cooling means ( 14 ), and a controller ( 12 ) for operating the cooling means ( 14 ) at various rates. The controller ( 12 ) is arranged to automatically operate the cooling means ( 14 ) at a first rate if the temperature rises above a first temperature threshold. The controller ( 12 ) is further arranged to automatically operate the cooling means ( 14 ) at a second increased rate if the temperature rises above a second temperature threshold. According to the invention, the point at which the monitored temperature reaches the second threshold may be delayed by operating the cooling means at a first rate prior to operating the cooling means at an increased second rate. In applications in which short periods of relatively high heat generation are experienced, the invention may delay the point at which the cooling means needs to be operated at a high level, reducing the overall noise generation of the cooling means.

1 . A method of cooling a device generating heat, comprising:
 monitoring a temperature associated with the device;   automatically operating a cooling means at a first rate if the monitored temperature rises above a first temperature threshold; and   automatically operating the cooling means at a second increased rate if the monitored temperature rises above a second temperature threshold,   wherein the first and/or the second temperature threshold is a function of a duration and/or an intensity of a peak power output of the device.   
     
     
         2 . The method of  claim 1 , further comprising:
 automatically decreasing the rate of the cooling means if the monitored temperature drops below the second temperature threshold.   
     
     
         3 . The method of  claim 2 , wherein the rate of the cooling means is automatically decreased to the first rate if the monitored temperature drops below the second temperature threshold. 
     
     
         4 . The method of  claim 1 , further comprising:
 automatically decreasing the rate of the cooling means if the monitored temperature drops below the first temperature threshold.   
     
     
         5 . The method of  claim 4 , wherein the rate of the cooling means is automatically decreased to zero if the monitored temperature drops below the first temperature threshold. 
     
     
         6 . The method of  claim 1 , wherein the rate of the cooling means is automatically increased from zero to the first rate if the monitored temperature rises above the first temperature threshold. 
     
     
         7 . The method of  claim 1 , wherein the rate of the cooling means is automatically increased from the first rate to the second increased rate if the monitored temperature rises above the second temperature threshold. 
     
     
         8 . The method of  claim 1 , wherein the rate of the cooling means is automatically increased to a maximum rate if the monitored temperature rises above the second temperature threshold. 
     
     
         9 . The method of  claim 1 , wherein the first/second rate of the cooling means is substantially constant if the monitored temperature is between the first and second temperature thresholds, or above the second temperature threshold. 
     
     
         10 . The method of  claim 1 , wherein first/second rate of the cooling means is varied if the monitored temperature is between the first and second temperature thresholds, or above the second temperature threshold. 
     
     
         11 . The method of  claim 1 , wherein the second temperature threshold is higher than the first temperature threshold. 
     
     
         12 . The method of  claim 1 , wherein the second rate of the cooling means is a maximum rate of the cooling means. 
     
     
         13 . The method of  claim 1 , further comprising;
 monitoring a current associated with the device; and   automatically operating the cooling means at the second increased rate if the monitored current rises above a current threshold.   
     
     
         14 . The method of  claim 13 , wherein the current threshold is from about 70% to about 90% of a maximum operating current of the device. 
     
     
         15 . The method of  claim 1 , wherein the first rate is from about 10% to about 25% of the second rate. 
     
     
         16 . The method of  claim 1 , wherein the first temperature threshold is from about 80% to about 90% of the second temperature threshold. 
     
     
         17 . The method of  claim 1 , wherein the first rate and/or the second rate is a function of a duration and/or an intensity of a peak power output of the device. 
     
     
         18 . The method of  claim 1 , wherein the first temperature threshold is independent of the device. 
     
     
         19 . A machine-readable medium having instructions stored thereon, wherein when read by a machine the instructions are configured to execute the steps of  claim 1 . 
     
     
         20 . A system for cooling a device generating heat, comprising:
 means for monitoring a temperature associated with the device;   cooling means; and   
       a controller for operating the cooling means at various rates, wherein the controller is arranged to automatically operate the cooling means at a first rate if the temperature rises above a first temperature threshold, wherein the controller is further arranged to automatically operate the cooling means at a second increased rate if the temperature rises above a second temperature threshold, and wherein the first and/or the second temperature threshold is a function of a duration and/or an intensity of a peak power output of the device. 
     
     
         21 . The system of  claim 20 , wherein the device is a motor drive, and/or the temperature monitoring means is a thermistor, and/or the cooling means is a fan.