Basic Control Algorithm - LG RCWW Operation & Maintenance Manual

4. CONTROL SYSTEM
30

4-3. Basic control algorithm

Unique P(proportional), I(integral), and D(differential) algorithms are applied to chilled water temperature control.
Compared to the conventional method, it allows optimal control by minimizing time to approach the target value, re-
maining deviation, Under-Shoot and Over-Shoot during initial startup and automatic/manual conversion of operation.
• Soft Loading
- Approach to the control target value with Soft startup
- Solved unnecessary stops caused by voltage change during startup
• Advanced Control
- Advanced high class control algorithm developed for high precision control compared to existing PID control
method.
- Prevention of temperature Cycling phenomenon caused by Overshoot/Undershoot during conversion from manual
mode to automatic mode.
- Reinforced safety control(Intensive Safety Control): By executing preventive control before chiller reaching abnor-
mal stop point, it minimizes unnecessary stops of the chiller.
LG's New Control
Algorithm
Over-shoot
Under-shoot
Figure 19. Control algorithm
General Control
Algorithm