© 2006 by Taylor & Francis Group, LLC
6-1
6
Control of Synchronous
Generators in
Power Systems
6.1
Introduction ........................................................................6-1
6.2
Speed Governing Basics ......................................................6-3
6.3
Time Response of Speed Governors ..................................6-7
6.4
Automatic Generation Control (AGC)..............................6-9
6.5
Time Response of Speed (Frequency) and
Power Angle .......................................................................6-11
6.6
Voltage and Reactive Power Control Basics ....................6-15
6.7
The Automatic Voltage Regulation (AVR) Concept .......6-16
6.8
Exciters ...............................................................................6-16
AC Exciters • Static Exciters
6.9
Exciter’s Modeling .............................................................6-19
New P.U. System • The DC Exciter Model • The AC Exciter •
The Static Exciter
6.10 Basic AVRs .........................................................................6-27
6.11 Underexcitation Voltage....................................................6-31
6.12 Power System Stabilizers (PSSs).......................................6-33
6.13 Coordinated AVR–PSS and Speed Governor
Control ...............................................................................6-37
6.14 FACTS-Added Control of SG...........................................6-37
Series Compensators • Phase-Angle Regulation and Unified
Power Flow Control
6.15 Subsynchronous Oscillations............................................6-42
The Multimass Shaft Model • Torsional Natural Frequency
6.16 Subsynchronous Resonance..............................................6-46
6.17 Summary............................................................................6-47
References .....................................................................................6-51
6.1 Introduction
Satisfactory alternating current (AC) power system operation is obtained when frequency an