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Part 3 Basic Control
Basic principle is to control the rpm of the motor by changing the working frequency of the compressor.
Three phase voltage is supplied to the motor and the time for which the voltage will supplied is controlled by IPM
(intelligent power module).
Switching speed of IPM defines the variable frequency input to the motor.
1. Normal operation
Fuzzy control : Maintain evaporating temperature (Te) to be constant on cooling mode and constant condensing temper-
ature (Tc) on heating mode by fuzzy control to ensure the stable system performance.
2. Compressor control
Cooling and heating load
System capacity
Linear control
Inverter linear control as cooling and heating load increasing
Actuator
Cooling operation
Heating operation
Stop state
Compressor
Fuzzy control
Fuzzy control
Stop
Fan
Fuzzy control
Fuzzy control
Stop
EEV
Super heating
fuzzy control
Super heating & Sub cooling
fuzzy control
Min. Pulse
EEV operates with fuzzy control rules to keep the degree of superheat (about 2~3℃) at the evaporator outlet status.
The degree of superheat = Tsuction – Tevaporation
Tsuction : temperature at suction pipe sensor(℃)
Tevaporation : evaporation temperature (℃)
3. EEV( Electronic Expansion Valve) control
※ 14,16k Models
Frequency that corresponds to each rooms capacity will be determined according to the difference in the tempera-
ture of each room and the temperature set by the remote controller.
There are various factors determining the frequency.
※ 14, 16k Models
Capacity steps of compressor are decided by summation of capacity code, outdoor temp., indoor temp., step com-
pensation of temperature difference indoor temp. and setting temp.
※ 14, 16k Models
EEV operates with PI control rules to keep the degree of superheat at the evaporator inlet and outlet status.