Electrically heated element thermoelectric effect

Abstract

Temperature estimation systems and methods for a powertrain of a vehicle, the powertrain comprising an electrically heated catalyst, utilize an electrical heater disposed proximate to the electrically heated catalyst, the electrical heater comprising a heating element and a controller configured to monitor a voltage of the electrical heater and estimate a temperature of the heating element of the electrical heater based on the monitored voltage of the electrical heater and a set of known thermoelectric effects. The estimated temperature could be utilized, for example, to estimate an exhaust gas temperature, which could then be leveraged for control of operating parameter(s) by the controller, such as engine fuel/air ratio.

1 . A temperature estimation system for a powertrain of a vehicle, the powertrain comprising an electrically heated catalyst, the temperature estimation system comprising:
 an electrical heater of the electrically heated catalyst disposed proximate to a catalyst of the electrically heated catalyst, the electrical heater comprising a heating element; and   a controller configured to:
 monitor a voltage of the electrical heater; 
 estimate a temperature of the heating element of the electrical heater based on the monitored voltage of the electrical heater and a set of known thermoelectric effects; and 
 estimate exhaust gas temperature of an engine of the powertrain based on the estimated temperature of the heating element, 
   wherein the powertrain does not include a dedicated thermocouple for measuring a temperature relative to the electrically heated catalyst.   
     
     
         2 . The temperature estimation system of  claim 1 , wherein the heating element of the electrical heater comprises two dissimilar metals arranged in parallel between a power terminal and a ground terminal. 
     
     
         3 . The temperature estimation system of  claim 2 , wherein the controller is configured to temporarily turn off a supply voltage to the electrical heater and monitor the voltage of the electrical heater as a voltage difference between the power and ground terminals. 
     
     
         4 . The temperature estimation system of  claim 3 , wherein the controller is otherwise configured to turn on the supply voltage to the electrical heater to thereby heat the catalyst of the electrically heated catalyst. 
     
     
         5 . The temperature estimation system of  claim 3 , wherein the set of known thermoelectric effects includes the Seebeck effect. 
     
     
         6 . The temperature estimation system of  claim 1 , wherein the electrical heater is disposed upstream from the catalyst of the electrically heated catalyst. 
     
     
         7 . The temperature estimation system of  claim 1 , wherein the catalyst of the electrically heated catalyst comprises one or more catalysts, and wherein the electrical heater is disposed mid-bed of or between the one or more catalysts of the electrically heated catalyst. 
     
     
         8 . The temperature estimation system of  claim 1 , wherein the electrical heater is disposed downstream of the catalyst of the electrically heated catalyst. 
     
     
         9 . The temperature estimation system of  claim 1 , wherein the controller does not utilize a resistance-based temperature modeling technique to model a temperature relative to the electrically heated catalyst. 
     
     
         10 . A temperature estimation method for a powertrain of a vehicle, the powertrain comprising an electrically heated catalyst, the temperature estimation method comprising:
 monitoring, by a controller, a voltage of an electrical heater of the electrically heated catalyst disposed proximate to a catalyst of the electrically heated catalyst, the electrical heater comprising a heating element;   estimating, by the controller, a temperature of the heating element of the electrical heater based on the monitoring of the voltage of the electrical heater and a set of known thermoelectric effects; and   estimating, by the controller, an exhaust gas temperature of an engine of the powertrain based on the estimated temperature of the heating element,   wherein the powertrain does not include a dedicated thermocouple for measuring a temperature relative to the electrically heated catalyst.   
     
     
         11 . The temperature estimation method of  claim 10 , wherein the heating element of the electrical heater comprises two dissimilar metals arranged in parallel between a power terminal and a ground terminal. 
     
     
         12 . The temperature estimation method of  claim 11 , further comprising temporarily turning off, by the controller, a supply voltage to the electrical heater and monitoring the voltage of the electrical heater as a voltage difference between the power and ground terminals. 
     
     
         13 . The temperature estimation method of  claim 12 , wherein the controller is otherwise configured to turn on the supply voltage to the electrical heater to thereby heat the catalyst of the electrically heated catalyst. 
     
     
         14 . The temperature estimation method of  claim 12 , wherein the set of known thermoelectric effects includes the Seebeck effect. 
     
     
         15 . The temperature estimation method of  claim 10 , wherein the electrical heater is disposed upstream from the catalyst of the electrically heated catalyst. 
     
     
         16 . The temperature estimation method of  claim 10 , wherein the catalyst of the electrically heated catalyst comprises one or more catalysts, and wherein the electrical heater is disposed mid-bed of or between the one or more catalysts of the electrically heated catalyst. 
     
     
         17 . The temperature estimation method of  claim 10 , wherein the electrical heater is disposed downstream of the catalyst of the electrically heated catalyst. 
     
     
         18 . The method of  claim 10 , wherein the controller does not utilize a resistance-based temperature modeling technique to model a temperature relative to the electrically heated catalyst.