
The hydrogen-cooled  
SGen-2000H generator series
with ratings from 310 MVA up to 600 MVA
SGen5-2000H at Otahuhu Combined Cycle Power Plant (New Zealand)
The SGen-2000H series of hydrogencooled, two-pole generators is part  
of Siemens Generator (SGen™) product 
line, with ratings up to 600 MVA for 
steam, gas and combined-cycle applications. 
Cooling performance is greatly enhanced 
through the use of hydrogen as cooling 
medium. Due to advanced material  
technologies and resulting heat transfer 
benefits, the generator components have 
been designed to achieve optimal performance while providing safe operation 
and reliability. In addition, frictional losses 
are significantly lower than those with 
air, thus improving the overall generator 
efficiency and performance.
Our innovative design philosophy strives 
to continually improve world-class generators in order to meet our customers 
varying requirements and provide utmost 
reliability and efficiency. 
Answers for energy.

Innovative design for world-class performance  
in power generation: The SGen-2000H generator series
1
 Thin laminations of high-grade, low-loss silicon steel are consolidated 
to form the stator core. Each lamination is electrically insulated with 
high-temperature capability material. The laminations are stacked to 
form the stator core with finger-plates and heavy end-plates at each  
end. Key bars and insulated through-bolts are used to maintain core  
integrity and tightness. The resultant stator core assembly features long 
lasting tightness, mechanical robustness, and excellent heat transfer 
characteristics.
2
 The generator stator winding assembly is manufactured with Vacuum 
Pressure Impregnation (VPI) technology or Global Vacuum Pressure  
Impregnation (GVPI). (G)VPI features advanced epoxy-mica insulation 
systems to ensure insulation integrity, to reduce the possibility of loose 
end-winding components and to reduce moisture and surface contamination, resulting in stator winding with high voltage endurance. 
3
 A patented core spring mounting system is used to reduce the noise 
level and transient forces. The design isolates the double operating  
frequency core vibration and reduces electrical transient forces on the 
generator frame and foundation. 
4
 The patented RIGI-FLEX
successful operation since the 1980s. This well proven bracing system  
provides rigidity to withstand transient fault loads combined with  
flexibility to withstand normal operation cyclic thermal expansion  
and contraction which occurs during start-ups and load changes. 
5
 An optimized rotor slot design provides uniform cooling flow through 
the rotor while also improving overall dynamic stability. A single-stage 
blower at each end of the generator results in a uniform thermal load  
in the generator rotor.
2
4
TM
 end-winding support system has been in 
1
5
33
Customer Benefits
 ■
Efficiency of up to 99 %
Hydrogen seal with carbon elements  ■ 
requires minimal seal oil and has  
improved emergency operating  
characteristics
 ■
Uniform temperature profile  
promotes reliability
 ■
Simplified installation
Transport dimensions suitable  ■ 
for rail transport in most countries
 ■
Design based on field-proven  
generator component designs
2
For over 60 years, Siemens has made 
many detailed improvements to the  
design of hydrogen-cooled generators. 
Additional improvements include:
 ■
Advanced Performance Plus™ seal  
system
 ■
Totally enclosed system minimizes  
the risk of contamination inside the 
generator 
 ■
Integrated & Compact Omega™  
Coolers

1
 Bearing Oil Catcher
2
 Carbon Seal
3
 Carbon Seal Bracket
4
 Stator Windings
5
 Rotating Blades
6
 Finger Plates
15
13
7
 Patented Core Spring 
Mounted System
8
 Winding Brace
9
 Blower Shroud
10
 Omega Cooler
11
 Blower Hub
1
3
2
12
 Bearing
13
 Rotor Shaft
14
 Excitation End
15
 Outer (Oil) Seal
4
6
5
14
12
8
11
9
10
7
Technical Data
Model Frequency Power Factor Apparent Power Efficiency Terminal Voltage
SGen5-2000H 50 Hz 0.85
SGen6-2000H 60 Hz 0.85
Coolant
Hydrogen at 4 to 5 bar
350 MVA to 
~600 MVA
310 MVA to 
~600 MVA
up to 99 % 16.5 kV to 22 kV
up to 99 % 19 kV to 23 kV
Design
Thermal Classification
Type of enclosure
Excitation
Transport dimensions
In accordance with IEC and ANSI standards and EU Directives
Class F insulation system
IP64 (IEC34-5); suitable for outdoor installation
Static
Suitable for rail transport in most countries
3

The hydrogen-cooled SGen-2000H generator series:  
References
Our hydrogen-cooled two-pole generator series exceeds an availability of 99.5% and  
counts with more than 100,000 operating hours which have earned Siemens a flawless  
reputation in the filed of reliable power generation steam and gas turbine applications.  
Therefore, the following references are only a few examples to illustrate the vast potentials  
of the SGen-2000H generator series.
Hamm-Uentrop, Germany 
Combined Cycle  
Power Plant
New Taweelah B, Dubai 
Combined Cycle  
Power Plant
Baosteel, Shanghai 
Steam Power Plant
Performance
Net plant output: 840 MW 1170 MW 350 MW
Commercial operation: 2007 2008 2009
Major components
Generator: 2x SGen5-2000H  1x SGen5-2000H
1x SGen5-2000H
3x SGen5-1000A
Steam turbine: 2x SST5-3000 Special solution  1 x SST5-5000
Gas turbine: 2x SGT5-4000F 3x SGT5-4000F
Published by and copyright © 2010: 
Siemens AG 
Energy Sector 
Freyeslebenstrasse 1 
91058 Erlangen, Germany
Siemens Energy, Inc. 
4400 Alafaya Trail 
Orlando, FL 32826-2399, USA
For more information, please contact  
our Customer Support Center. 
Phone: +49 180/524 70 00 
Fax: +49 180/524 24 71 
(Charges depending on provider) 
E-mail: support.energy@siemens.com
For more information please contact 
your local Siemens sales representative.
Fossil Power Generation Division 
Order No. E50001-W210-A148-X-4A00  
Printed in Germany 
Dispo 34802, c4bs No. 7449 
TH 214-100269 431160 DB 08102.0
Printed on elementary chlorine-free  
bleached paper.
All rights reserved. 
Tradem arks me ntioned in thi s docum ent  
are the p roperty of Sie mens AG, its af filiate s,  
or their respective owners.
Subject to change without prior notice. 
The information in this document contains  
gene ral des cription s of th e techni cal opt ions  
available, which may not apply in all cases.  
The required technical options should therefore  
be specified in the contract.
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