CAT Titan 250 - Manual (Page 42)

Turbomachinery Package Specification Titan 250 Generator Set
10.2 Generator Control
10.2.1 Functional Description
The Turbotronic 4 control system working in conjunction with the generator’s excitation
system provides control, monitoring, and protection of the generator and its output. The
key components are:
• Permanent magnet generator (PMG)
• Rotating armature-type AC exciter
• Full-wave rectifier assembly
• CGCM
Figure 19 provides a simplified layout of these components. The exciter armature is
mounted on the main generator rotor and generates an AC voltage as it revolves in the
magnetic flux produced by the stationary field. The stationary field is wound on salient
poles supported by the stator core or frame. The PMG consists of permanent magnets on
the generator rotor and a stationary armature, also supported by the generator frame.
The rotating rectifier assembly rectifies the exciter armature AC output to DC. In turn, the
DC power is applied to the main generator rotating field windings. The complete exciter is
enclosed and protected by a removable cover. When the rotor operates at synchronous
speed, the PMG provides power to the CGCM. The CGCM provides the appropriate
exciter field current to control the exciter armature output, which is rectified to provide DC
power to the main generator rotating field winding.
EXCITATION OUTPUT
GENERATOR CIRCUIT
BREAKER
BUS
EXCITATION POWER
LOAD SHARE LINES
(To other Combined Generator Control
Module or Load Share Module)
GENERATOR
ARMATURE
(Stationary)
GENERATOR
FIELD
RECTIFIER
ASSEMBLY
EXCITER
ARMATURE
EXCITER FIELD
(Stationary)
GENERATOR
POTENTIAL
TRANSFORMERS
GENERATOR
CURRENT
TRANSFORMERS
CROSS CURRENT
COMPENSATION
TRANSFORMER
BUS
POTENTIAL
TRANSFORMERS
GENERATOR
COMBINED GENERATOR CONTROL MODULE
CONTROLNET To Turbotronic 4 Control Processor
PERMANT
MAGNET
GENERATOR
ROTATI
N
G
P
O
RTION
Figure 19. Typical Generator, Exciter, and Generator Control Module Arrangement
© 2008 Solar Turbines Incorporated. All rights reserved. TPS250GS/908 - Preliminary
41