Honeywell AUTOMATIC CONTROL SI Edition

ENGINEERING MANUAL OF AUTOMATIC CONTROL
CONTROL FUNDAMENTALS
3
CONTENTS
Control Fundamentals
ENGINEERING MANUAL OF AUTOMATIC CONTROL
Introduction ............................................................................................................ 5
Definitions ............................................................................................................ 5
HVAC System Characteristics ............................................................................................................ 8
General................................................................................................ 8
Heating ................................................................................................ 9
General ........................................................................................... 9
Heating Equipment ......................................................................... 10
Cooling ................................................................................................ 11
General ........................................................................................... 11
Cooling Equipment.......................................................................... 12
Dehumidification.................................................................................. 12
Humidification ...................................................................................... 13
Ventilation ............................................................................................ 13
Filtration............................................................................................... 14
Control System Characteristics ............................................................................................................ 15
Controlled Variables ............................................................................ 15
Control Loop ........................................................................................ 15
Control Methods .................................................................................. 16
General ........................................................................................... 16
Analog and Digital Control .............................................................. 16
Control Modes ..................................................................................... 17
Two-Position Control ....................................................................... 17
General ....................................................................................... 17
Basic Two-Position Control ......................................................... 17
Timed Two-Position Control ........................................................ 18
Step Control .................................................................................... 19
Floating Control............................................................................... 20
Proportional Control ........................................................................ 21
General ....................................................................................... 21
Compensation Control ................................................................ 22
Proportional-Integral (PI) Control .................................................... 23
Proportional-Integral-Derivative (PID) Control ................................ 25
Enhanced Proportional-Integral-Derivative (EPID) Control............. 25
Adaptive Control.............................................................................. 26
Process Characteristics....................................................................... 26
Load ................................................................................................ 26
Lag .................................................................................................. 27
General ....................................................................................... 27
Measurement Lag....................................................................... 27
Capacitance................................................................................ 28
Resistance .................................................................................. 29
Dead Time .................................................................................. 29
Control Application Guidelines ............................................................ 29