CAT Titan 250 Manual De Usuario

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Turbomachinery Package Specification 
Titan 
250 Generator Set 
Any variations in bus potential will also be sensed and corrected by this circuit. After 
voltage builds, the generator accelerates to 100% speed and excitation and voltage 
control is assumed by the CGCM. A crosscurrent-compensating transformer provides the 
signal to the CGCM for reactive loadsharing between multiple paralleled units. 
It should be noted that the generator rotor windings rotate and the generator armature is 
stationary. The exciter field coils are also stationary and the exciter armature rotates with 
the main generator rotor shaft. As a result, a single rotating assembly consisting of the 
exciter armature, exciter rectifier, and the generator rotor windings is formed. This single 
rotating assembly greatly simplifies all electrical connections within the generator. 
5.2.1 Standard 
Features 
Generators include the following standard features: 
•  Sleeve bearings with pressure fed sumps 
•  Terminal box 
•  Form wound stator windings 
•  Amortisseur windings 
•  Rotor balance to 125% rated speed 
•  Anti-condensation space heaters  
•  Permanent magnet generator (PMG) 
•  Rotating armature-type VAC exciter 
•  Full-wave rectifier assembly 
Special order generators are available to meet unique customer requirements including 
non-U.S. specifications. 
5.2.2 Rotor 
The salient, four-pole, forged rotor is dynamically balanced to minimize vibration. Motor 
fans move cooling air through the generator and around the rotor. The rotors have  
layer-wound field windings cemented with a high-strength resin and are baked to cure the 
resin. The rotor is in electrical and mechanical balance at all speeds up to 125% of rated 
speed. 
5.2.3 Stator 
The stator is built with high-grade silicon steel laminations that are precision-punched and 
individually insulated. Windings are typically form-wound and treated with thermosetting 
synthetic varnish or vacuum pressure impregnated (VPI) epoxy for maximum moisture 
resistance, high dielectric strength, and high bonding qualities. The windings are braced 
to withstand shock loads such as motor starting and short circuits. Space heaters can be 
supplied to minimize condensation during shutdowns. 
5.2.4 Shaft 
The shaft diameter provides the necessary stiffness to avoid torsional vibration. The 
turbine-driven generator set is given a complete torsional analysis. 
5.2.5 Frame 
The frame is heavy-duty steel and is fabricated with deep welds and internal reinforcing 
for extra rigidity and strength. The frame also includes lifting lugs. 
5.2.6 Exciter 
Excitation current for the generator field coils is provided by a brushless rotating exciter 
with a PMG pilot exciter. The exciter is mounted directly on the generator rotor shaft. The 
exciter consists of two basic parts, a small three-phase, AC generator with rotating 
© 2008 Solar Turbines Incorporated. All rights reserved. 
TPS250GS/908 - Preliminary 
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