G E N E R A T O R S
AVR12 – PERMANENT
MAGNET
GENERATOR
The permanent magnet generator (PMG) option
upgrades the excitation system of the generator
from the standard self-excited system to a
separately-excited system. The PMG couples to
the non-drive end of the generator and provides
an independent source of excitation power that
ensures initial voltage build-up. The PMG
improves the voltage response of the generator
during transient load application, such as motor
starting, and provides a sustained short-circuit
current for the operation of protective devices.
Isolation of the excitation power ensures that
regulation is not affected by non-linear
distorting loads.
Electrical Power Output
Power
Set reference
Sense
AVR
Output
Main Stator
Stator
of PMG
Mechanical
Rotation
Power
Input
Main Field
(rotor)
Permanent
Magnet
Field
(rotor)
Diode Bridge
BLOCK DIAGRAM OF PMG
www.CAT-ElectricPower.com
278-397
© 2003 Caterpillar
All rights reserved.
Printed in U.S.A.
Materials and specifications are subject to change without notice.
The International System of Units (SI) is used in this publication.
LEHX0477-03 (10-03)
W H E R E
T H E
W O R L D
T U R N S
F O R
P O W E R