This document discusses the structural analysis of a wound rotor shaft for a 2.1 MW wind turbine operating at various speeds and frequencies. It analyzes a single-piece steel rotor shaft and models its geometry and meshing. It then presents the results of the total deformation, maximum stress, and maximum strain on the shaft material from simulations run at rated speed, over speed, and critical speed for frequencies of 50Hz and 60Hz. The analysis shows the steel material is capable of withstanding the stresses and strains from operating at various speeds and frequencies for the wind turbine application.

1. ` ISSN 2394-3777 (Print)
ISSN 2394-3785 (Online)
Available online at www.ijartet.com
International Journal of Advanced Research Trends in Engineering and Technology (IJARTET)
Vol. II, Special Issue XXII, February 2015 in association with
JEPPIAAR INSTITUTE OF TECHNOLOGY, SRIPERUMBUDUR,
DEPARTMENT OF MECHANICAL ENGINEERING
NATIONAL CONFERENCE ON PROMISING RESEARCH & INNOVATIONS IN MECHANICAL ENGINEERING
( PRIME-2015)
25
TH
FEBRUARY 2015
30
All Rights Reserved © 2015 IJARTET
Windmill wound rotor structral analysis at various
speed
V.KANAN1
, , P.VIJAYASARATHI2
T. VENKATAMUNI3,
V.Anish4
1&2
(Mechanical Department, Anna university Research scholar, Chennai, India)
3
(DOCTRATE, Mechanical Department, Jeppiaar Institute Of Technology, Kunnam, Chennai, India)
4
(Third year student, Mechanical Department, Jeppiaar Institute Of Technology, Kunnam, Chennai, India)
Abstract—In windmill induction generator wound rotor shaft
is very crucial to make power production from the wind. so
design and material selection of wound rotor is very challenging
one. This work deals with In 2.1 MW wind mill the replacement
of conventional two-piece steel rotor shaft with a single-piece
wound rotor STEEL (SM45C) material in 50 HZ and 60 HZ
various frequency at various speed like Rated speed (1512 rpm),
over speed (2150 rpm), critical speed (2580 rpm) conditions
structural analysis and its performance to select proper material
and make the perfect design to avoid the defects and better
efficiency of power production.
Keywords—wound rotor, steel (SM45C), 50HZ, rated speed,
over speed, critical speed
I. INTRODUCTION
Rotor shaft is a single piece solid forging manufactured
from a vacuum casting. Slots for insertion of field winding are
milled into the rotor body. The longitudinal slots are
distributed over the circumference. So that solids poles are
obtained. To ensure that only high quality forgings are used,
strengthen test, material analysis and ultrasonic tests are
performed during manufacture of the rotor. After completion,
the rotor is based in various planes at different speeds and then
subjected to an over speed test at 120% of rated speed for two
minutes.
II. DATA FOR 2.1 MW, 50 HZ WOUND ROTOR
A. SPIDER SHAFT
Mass of the spider shaft ms =760 kg
Length of the spider shaft LT =2745.5 mm
Overhang after the brg end faces@ DE (42 kg overhang)
=310mm
Overhang after the brg end faces@ NDE (24 kg overhang)
=417 mm
Length of the shaft for calculation (2745-310-
417+34+31)L =2018.5 mm
Mass of the spider shaft m1 =694 kg
Total mass of the shaft (m1XL)mc =1400839 kg-mm
Equivalent diameter of shaft d =237 mm
B. ROTOR CORE & WINDING
Mass of the rotor core mR =1510 kg
Mass of the rotor winding mw =460 kg
Total mass of the wound rotor without shaft m =1970 kg
Total mass of the wound rotor with shaft M =2730 kg
III. PROPERTIES OF THE STEEL MATERIALS
Mechanical
properties
Symbol Units Steel
Young’s modulus E GPa 207
Shear modulus G GPa 80
Poisson’s ratio γ ---- 0.3
Density ρ Kg/m3 7600
Yield strength Sy MPa 370
Shear strength SS MPa ----

2. ` ISSN 2394-3777 (Print)
ISSN 2394-3785 (Online)
Available online at www.ijartet.com
International Journal of Advanced Research Trends in Engineering and Technology (IJARTET)
Vol. II, Special Issue XXII, February 2015 in association with
JEPPIAAR INSTITUTE OF TECHNOLOGY, SRIPERUMBUDUR,
DEPARTMENT OF MECHANICAL ENGINEERING
NATIONAL CONFERENCE ON PROMISING RESEARCH & INNOVATIONS IN MECHANICAL ENGINEERING
( PRIME-2015)
25
TH
FEBRUARY 2015
31
All Rights Reserved © 2015 IJARTET
IV. MODELING OF THE GEOMETRY
Real structures, components or domains are in general very
complex, and have to be reduced to a manageable geometry.
Curved parts of the geometry and its boundary can be modeled
using curves and curved surfaces. However, it should be noted
that the geometry is eventually represented by a collection of
elements, and the curves and curved surfaces are
approximated by piecewise straight lines or flat surfaces. The
analysts have to interpret the results of the simulation with
these geometric approximations in mind. Representation of the
curved parts by straight edges would be smoother and more
accurate.
FIG. 1 . SHAFT WITH ROTOR CORE ASSEMBLY
MODELING
V. MESHING
Mesh generation is a very important task of the pre-
process. It can be a very time consuming task to the analyst,
and usually an experienced analyst will produce a more
credible mesh for a complex problem. The domain has to be
meshed properly into elements of specific shapes such as
triangles and quadrilaterals. Information, such as element
connectivity, must be created during the meshing for use later
in the formation of the FEM equations. It is ideal to have an
entirely automated mesh generator, but unfortunately this is
currently not available in the market. A semi-automatic pre-
processor is available for most commercial application
software packages. There are also packages designed mainly
for meshing. Such packages can generate files of a mesh,
which can be read by other modeling and simulation packages.
FIG. 1 . SHAFT WITHOUT ROTOR CORE ASSEMBLY MESHING
VI. TOTAL DEFORMATION ANALYSIS RESULT FOR
STEEL(SM45C)
FIG. 1 . 50 HZ RATED SPEED (1512 rpm)

3. ` ISSN 2394-3777 (Print)
ISSN 2394-3785 (Online)
Available online at www.ijartet.com
International Journal of Advanced Research Trends in Engineering and Technology (IJARTET)
Vol. II, Special Issue XXII, February 2015 in association with
JEPPIAAR INSTITUTE OF TECHNOLOGY, SRIPERUMBUDUR,
DEPARTMENT OF MECHANICAL ENGINEERING
NATIONAL CONFERENCE ON PROMISING RESEARCH & INNOVATIONS IN MECHANICAL ENGINEERING
( PRIME-2015)
25
TH
FEBRUARY 2015
32
All Rights Reserved © 2015 IJARTET
FIG. 2 . 50 HZ OVER SPEED (2150 rpm)
FIG. 3 . 50 HZ CRITICAL SPEED (2580 rpm)
FIG. 4 . 60 HZ RATED SPEED (1512 rpm)
FIG. 5 . 60 HZ OVER SPEED (2150 rpm)

4. ` ISSN 2394-3777 (Print)
ISSN 2394-3785 (Online)
Available online at www.ijartet.com
International Journal of Advanced Research Trends in Engineering and Technology (IJARTET)
Vol. II, Special Issue XXII, February 2015 in association with
JEPPIAAR INSTITUTE OF TECHNOLOGY, SRIPERUMBUDUR,
DEPARTMENT OF MECHANICAL ENGINEERING
NATIONAL CONFERENCE ON PROMISING RESEARCH & INNOVATIONS IN MECHANICAL ENGINEERING
( PRIME-2015)
25
TH
FEBRUARY 2015
33
All Rights Reserved © 2015 IJARTET
FIG. 6 . 60 HZ CRITICAL SPEED (2580 rpm)
VII. ANALYSIS TOTAL DEFORMATION TABULAR
RESULT
STEEL(SM45C)
TOTAL
DEFLECTION
(mm)
MAX
STRESS
(N/mm)
MAX
STRAIN
50
Hz
RATED SPEED
(1512rpm)
5.4×10-5 0.018 6.6×10-7
OVER SPEED
(2150rpm)
3.8×10-5 0.012 4.7×10-7
CRITICAL SPEED
(2580rpm)
3.1×10-5 0.010 3.9×10-7
60
Hz
RATED SPEED
(1812rpm)
4.5×10-6 0.0015 5.5×10-8
OVER SPEED
(2760rpm)
2.9×10-5 0.0099 3.6×10-7
CRITICAL SPEED
(3312rpm)
2.4×10-5 0.0082 3.05×10-7
VIII.CONCLUSION
Structural analysis using ANSYS software results are used
to check the perfect design and capability of wind mill wound
rotor steel (SM45C) material in various frequency 50 HZ and
60 HZ at various speed like Rated speed (1512 rpm), over
speed (2150 rpm), critical speed (2580 rpm) dynamic
conditions. This paper further will useful to compare with the
composite materials and choose best material.
.
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