Normal Operation; Compressor Control; Eev( Electronic Expansion Valve) Control - LG A2UW18GFA0 Svc Manual

Part 3 Basic Control

1. Normal operation

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.
Actuator
Compressor
Fan
EEV
※ 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.

2. Compressor control

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.
※ 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.

3. EEV( Electronic Expansion Valve) control

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 (℃)
※ 14, 16k Models
EEV operates with PI control rules to keep the degree of superheat at the evaporator inlet and outlet status.
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Only for training and service purposes
Cooling operation
Fuzzy control
Fuzzy control
Super heating Super heating & Sub cooling
fuzzy control
Inverter linear control as cooling and heating load increasing
- 30 -
Heating operation
Fuzzy control
Fuzzy control
fuzzy control
Linear control
Cooling and heating load
Stop state
Stop
Stop
Min. Pulse
LGE Internal Use Only