Heat pump system control method for vehicle
View Patent ↗A heat pump system control method for a vehicle includes a process (A) of operating a compressor of an air conditioner to cool or heat an interior of the vehicle while the vehicle is driving, measuring by a controller initial states of the compressor and a refrigerant based on data detected from a data detector, and monitoring the compressor, a process (B) of determining by the controller whether a current coil temperature of a motor unit provided in the compressor is higher than a coil specification temperature through the process (A) and operating a protection mode; and a process (C) of, when the process (B) is completed, calculating by the controller a slope of a coil temperature of the motor unit over time, determining whether the temperature slope is greater than zero (0) three times consecutively to stop the operation of the compressor, and terminating control.
1. A heat pump system control method for a vehicle, the method comprising:
a process (A) of operating a compressor of an air conditioner to cool or heat an interior of the vehicle while the vehicle is driving, and measuring by a controller initial states of the compressor and a refrigerant based on data detected from a data detector, and monitoring the compressor;
a process (B) of determining by the controller whether a current coil temperature of a motor unit provided in the compressor is higher than a coil specification temperature through the process (A) and operating a protection mode; and
a process (C) of, when the process (B) is completed, calculating by the controller a slope of a coil temperature of the motor unit over time, determining whether the temperature slope is greater than zero (0) three times consecutively to stop the operation of the compressor, and terminating control.
2. The method of claim 1 , wherein:
the process (A) comprises:
circulating the refrigerant in the air conditioner by driving the compressor according to a user's request for cooling or heating the interior of the vehicle;
an initial state measurement step of, by the controller, measuring current and voltage of the motor unit and measuring an initial temperature of the refrigerant; and
calculating, by the controller, a resistance of the motor unit using the current and voltage of the motor unit measured in the initial state measurement step and measuring and monitoring the coil temperature of the motor unit.
3. The method of claim 2 , wherein:
the process (B) comprises:
determining, by the controller, whether the current coil temperature of the motor unit monitored through the process (A) is higher than the coil specification temperature; and
operating the protection mode if it is determined that the current coil temperature of the motor unit is higher than the coil specification temperature.
4. The method of claim 3 , wherein:
in the determining whether the current coil temperature of the motor unit is higher than the coil specification temperature,
if it is determined that the current coil temperature of the motor unit is lower than the coil specification temperature, then the controller returns to the step of monitoring the compressor.
5. The method of claim 3 , wherein:
in the operating the protection mode, when the vehicle is in a cooling mode or in a cooling and battery cooling mode, the controller stops operation of a first expansion valve and increases flow rate of the refrigerant inflowing into a chiller by control of a second expansion valve.
6. The method of claim 3 , wherein:
in the operating the protection mode, when the vehicle is in a heating mode or a heating and dehumidifying mode, the controller increases flow rate of the refrigerant inflowing into a heat-exchanger by control of a third expansion valve.
7. The method of claim 3 , wherein:
the process (C) comprises:
calculating, by the controller, the coil temperature slope of the motor unit over time;
determining, by the controller, whether the coil temperature slope calculated in the calculating the coil temperature slope is greater than zero (0) three times consecutively; and
stopping the operation of the compressor and terminating the control if it is determined that the coil temperature slope is greater than zero (0) three times consecutively in the determining whether the coil temperature slope is greater than zero (0) three times consecutively.
8. The method of claim 7 , wherein:
if it is determined that the coil temperature slope is not greater than zero (0) three times consecutively in the determining whether the coil temperature slope is greater than zero (0) three times consecutively, the controller returns to the monitoring of the compressor.
9. The method of claim 2 , wherein:
in the monitoring, the coil temperature of the motor unit is determined by
T
=
(
R
-
R
0
R
0
)
×
(
K
+
T
0
)
+
T
0
,
where T is a temperature of a winding, T 0 is an initial temperature of the winding, R is a winding resistance at the temperature, R 0 is the winding resistance at the temperature T 0 , and K is a temperature coefficient of the winding.
10. The method of claim 1 , wherein:
the data detector comprises:
an air conditioning switch configured to turn on and off operation of the air conditioner;
a refrigerant temperature sensor configured to measure a temperature of the refrigerant;
a current sensor configured to measure current of the motor unit; and
a voltage sensor configured to measure voltage of the motor unit.