Control method of air conditioner in electrical vehicle

Abstract

A control method is provided for an air conditioning control system which includes determining whether either a desired discharge temperature from an air-conditioning system to maintain the internal temperature of a vehicle at a desired internal cabin temperature and a desired evaporator temperature that is temperature of an evaporator satisfies a heater operating condition. The heater is then operated in accordance with temperature and traveling conditions of the vehicle to output a desired discharge temperature when the heater operating conditions are satisfied. When, however, a heater discharge temperature from the heater is greater than or equal to a reference heater or the heater discharge temperature is greater than the desired discharge temperature by at least a predetermined temperature or more, then the heater is turned off to prevent over consumption of electricity.

1 . A control method of an air conditioner, comprising:
 determining, by a controller, whether at least one of a desired discharge temperature from an air-conditioning system to maintain the internal temperature of a vehicle at a desired internal temperature and a desired evaporator temperature that is the temperature of an evaporator satisfy a heater operating condition;   controlling, by the controller, the operation of the heater in accordance with temperature and traveling conditions of the vehicle to output the desired discharge temperature when the heater operating conditions are satisfied; and   turning off, by the controller, the heater when a heater discharge temperature from the heater is a reference temperature or more or the heater discharge temperature is larger than the desired discharge temperature by a predetermined temperature or more when the heater is driven.   
     
     
         2 . The method as defined in  claim 1 , further comprising:
 in response to turning off the heater, initiating a process which re-determines whether at least the desired discharge temperature and the desired evaporator temperature satisfies the heater operating condition; and   turning on the heater when the heater operation condition is satisfied and the desired discharge temperature is less than or equal to a first temperature T 6  and the heater discharge temperature is less than the desired discharge temperature plus 15° C.   
     
     
         3 . The method as defined in  claim 2 , wherein when the heater operating condition is satisfied and the desired discharge temperature is greater than the first temperature T 3 , the heater is turned back on when the heater discharge temperature is lower than a second temperature T 7 . 
     
     
         4 . The method as defined in  claim 2 , wherein when the desired evaporator temperature is 2° C. higher than the currently measured evaporator temperature or the desired discharge temperature is 4° C. higher than the desired evaporator temperature, the controller determines that the heater operating condition is satisfied. 
     
     
         5 . The method as defined in  claim 1 , further comprising keeping the heater at maximum capacity for a predetermined time so that the heater may be controlled after a predetermined time is passed when a air-conditioner in the air-conditioning system is operated, as a result of determining whether the air-con is operated when the operation condition is satisfied in determining of the operating condition. 
     
     
         6 . The method as defined in  claim 5 , wherein the heater control is performed when the controller determines that the air-con has not been operated. 
     
     
         7 . The method as defined in  claim 1 , wherein the heater is turned off when the heater discharge temperature is 85° C. or more, which is a second reference temperature T 4 , or the heater discharge temperature is greater than the desired discharge temperature by at least 20° C., which is a predetermined temperature T 5 . 
     
     
         8 . An air-conditioning system for a vehicle, comprising:
 a heater configured to output a temperature T o ;   an evaporator in an air conditioner configured to output a temperature T e ;   a controller configured to determine whether at least one of a desired discharge temperature from an air-conditioning system and a desired evaporator temperature satisfy a heater operating condition, control the operation of the heater in accordance with temperature and traveling conditions of the vehicle to output the desired discharge temperature when the heater operating condition is satisfied; and turning off the heater when a heater discharge temperature from the heater is greater than a reference temperature T 2  or that the heater discharge temperature is greater than the desired discharge temperature plus a predetermined amount T 3  while the heater is being operated.   
     
     
         9 . The air-conditioning system as defined in  claim 8 , wherein the controller is further configured to initiating a process which re-determines whether at least the desired discharge temperature and the desired evaporator temperature satisfies the heater operating condition in response to turning off the heater, and turn on the heater when the heater operation condition is satisfied and the desired discharge temperature is less than or equal to a first temperature T 6  and the heater discharge temperature is less than the desired discharge temperature plus 15° C. 
     
     
         10 . The air-conditioning system as defined in  claim 9 , wherein when the heater operating condition is satisfied and the desired discharge temperature is greater than the first temperature T 3 , the heater is turned back on when the heater discharge temperature is lower than a second temperature T 7 . 
     
     
         11 . The air-conditioning system as defined in  claim 9 , wherein when the desired evaporator temperature is 2° C. higher than the currently measured evaporator temperature or the desired discharge temperature is 4° C. higher than the desired evaporator temperature, the controller determines that the heater operating condition is satisfied. 
     
     
         12 . The air-conditioning system as defined in  claim 8 , wherein the controller is further configured to keep the heater at maximum capacity for a predetermined time so that the heater may be controlled after a predetermined time is passed when a air-conditioner in the air-conditioning system is operated, as a result of the determination whether the air-con is operated when the operation condition is satisfied in the determination of the operating condition. 
     
     
         13 . The air-conditioning system as defined in  claim 12 , wherein heater control is performed when the controller determines that the air-con has not been operated. 
     
     
         14 . The air-conditioning system as defined in  claim 8 , wherein the controller is configured to turn off the heater when the heater discharge temperature is 85° C. or more, which is a second reference temperature T 4 , or the heater discharge temperature is greater than the desired discharge temperature by at least 20° C., which is a predetermined temperature T 5 . 
     
     
         15 . The in air-conditioning system as defined in  claim 8  wherein the heater is a Positive Thermal Coefficient (PTC) heater. 
     
     
         16 . A computer readable medium containing executable program instructions executed by a processor, comprising:
 program instructions that determine whether at least one of a desired discharge temperature from an air-conditioning system to maintain the internal temperature of a vehicle at a desired internal temperature and a desired evaporator temperature that is the temperature of an evaporator satisfy a heater operating condition;   program instructions that control the operation of the heater in accordance with temperature and traveling conditions of the vehicle to output the desired discharge temperature when the heater operating conditions are satisfied; and   program instructions that turn off the heater when a heater discharge temperature from the heater is a reference temperature or more or the heater discharge temperature is larger than the desired discharge temperature by a predetermined temperature or more when the heater is driven.