FIELD OF INVENTION
The present invention relates to a process for setting co-ordinates upper and
lower stator bars of a turbo generator on a baking wagon,
BACKGROUND OF THE INVENTION
In 210MW THW type turbogenerator (TG), there are 60 Lower and 60 Upper
type stator bars. The insulation on these stator bars are done through VPI
Process, after Impregnation of the stator bars, these are pressed on a baking
wagon, and cured in the oven,
6 Stator bars are pressed on the baking wagon as per standard regime. These all
6 bars can either be Lower or Upper Type,
After completion of first set of 6 stator bars a second set of 6 stator bars are
manufactured. These second set of stator bars are checked on a wooden model.
In this wooden model, the Upper and the Lower stator bars are placed together
to check their profile including matching. After receipt of clearance from the
model checking, the next 54 Lower and 54 Upper bars are manufactured.
In prior art practice, following disadvantages are observed:
1- The co-ordinates of the baking has to be set for the lower stator bars first,
and then change into those for first 6 bars of each Lower and Upper type.
Then again the co-ordinates are to be reset for the lower stator bar for next
54 Lower type Stator bars. Again co-ordinate setting of the lower bar had to
be changed into upper for completion of the remaining 54 Upper stator bars.
2- Thus, the prior art takes at least four wagon co-ordination settings, which
takes a long time.
OBJECTS OF INVENTION
It is therefore an object of the invention to propose a process for setting co-
ordinates of Upper Stator bars simultaneously with Lower Stator bars of a turbo
generator on baking wagon.
SUMMARY OF INVENTION
The inventors through experimentations and analysis of the prior art
disadvantages recognized that one possible solution to the problem o frequent
change in co-ordinate setting can be that co-ordinates setting be done on the
baking wagon for the Lower and upper type stator bars together at a time. This
should prevent the requirement of complete change in setting on the wagon on
frequent basis. As shown in Table - 1, the following data is collected during an
exemplary co-ordinate setting of the stator bars on the turbine side and the
exciter side of a 210MW TG:
With careful analysis of the data relating to co-ordinates for wagon setting as per
table no.-l technical parameters are revealed,
1- Co-ordinates 'H' is considerably high in the lower stator bars as compared
to the upper type stator bars at each end. The height of the supporting
beam has to be changed to adjust with the height of all 6 Lug-Rest. So,
this co-ordinate is recognised as the co-ordinate due to which, whole
wagon setting has to be changed for the upper and lower type of stator
bars on every occasions.
2- Co-ordinate 'L' remains unchanged and identical for the lower as well as
the upper type stator bars at Exciter side including the Turbine side.
3- Co-ordinate 'E' can be adjusted independently on the wagon for the Lower
and upper type stator bars. For Normal and Terminal type stator bars out
of the lower and upper stator bars can simultaneously be adjusted on the
wagon. For setting of this co-ordinate 'E', only a first lug rest (03) has to
be shifted along the length of the supporting beam (5).
With the above findings, it can be concluded that, Co-ordinate 'H' can be
adjusted for the lower bars with insertion of a packing (8) below a second lug-
rest (9) on the supporting beam (5) adjusted for the upper bar.
Above findings make it feasible to produce the lower type stator bars along with
the upper type stator bars.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 - shows a stator bar (1) on a wagon (2).
Figure 2 - shows an upper type of stator bars pressed on a wagon according to
prior art.
Figure 3 - shows setting of a Lower type lug rest (9) and upper type of LugOrrest
(3) on the wagon at a time according.
DETAIL DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
The slot portion (straight Length) of the stator bar (1) is placed on the wagon
(2), and its lug (7) is supported on a first Lug-rest (3). Position of c-ordinate V
of the stator bar in relation to the wagon (2) is shown in figure -1.
As shown in figure-2, the Lugs (7) of the stator bars (1) are clamped on the first
lug rest (3) by ,a Clamp (6). The Lug rest (3) is mounted on its base (4). This
base (4) is attached on a supporting beam (5). In figure-2, only 2 similar bars
are shown, however similar 6 bars are actually on the wagon (2). Position of co-
ordinates 'H' and 'E' of the stator bar with respect to the wagon is shown.
As shown in figure-3, a packing (8) is inserted between the lower type of lug-rest
(9) and its base (4) to adjust the height of the co-ordinate 'H' on the supporting
beam (5) adjusted for the upper type of lug-rest (3).
In figure-3, only one Lower and one upper type lug rest is shown, however at
least three type and three upper type lug rest are provided on the supporting
beam (5).
Accordingly, the stator bars are placed on wagon (2) which has the setting of co-
ordinate 9as per table no.-l) based on the type of stator bar (1).
On setting of the lower type stator bars, it is very easy to change the co-
ordinates from Normal type to terminal type stator bars and vice versa. Similar is
the arrangement for the Upper type stator bars.
Main problem comes in switching from the Lower to upper type stator bar and
vice-versa while co-ordinates setting, because it needs to change the height of
the supporting beann (5).
This problem is overcome by the invention through a modified process of setting
comprising:
- adjusting a baking wagon for upper type of stator bars;
- replacing three of the upper bars with 3 lug rest (9) of the lower type
stator bar;
- adjusting a supporting beam (5) for the upper type of stator bar to have 3
lug rest of the Lower type and 3 lug rest of the upper type stator bar;
- inserting a packing (8) below the lug rests (9) of the lower type stator
bars (1), the height of the packing (8) is such that it adjusts the co-
ordinate *H' of the lower type stator bar on the supporting beam (5); and
- setting the Co-ordinate 'E' and V for each of the lug rest (3,9)
individually, the co-ordinate position 'E' 'H' and V being turbine side and
exciter side length of upper normal, upper terminal, lower normal, and
lower terminal stator bar.
Now the wagon is set for three lower and three upper type stator bars
This arrangement provide following advantages:-
1. Saving of complete Co-ordinates setting
2. Saving of Man-Power and Time consumption
WE CLAIM
1. A process of simultaneous setting of upper and lower stator bars of a
turbo generator on a baking wagon during providing higii voltage
insulation on the stator bars, the process comprising the steps of:
- adjusting a baking wagon for upper type of stator bars;
- replacing three of the upper bars with 3 lug rest (9) of the lower type
stator bar;
- adjusting a supporting beam (5) for the upper type of stator bar to have 3
lug rest of the Lower type and 3 lug rest of the upper type stator bar;
- inserting a packing (8) below the lug rests (9) of the lower type stator
bars (1), the height of the packing (8) is such that it adjusts the co-
ordinate 'H' of the lower type stator bar on the supporting beam (5); and
- setting the Co-ordinate 'E' and V for each of the lug rest (3,9)
individually, the co-ordinate position 'E' 'H' and V being turbine side and
exciter side length of upper normal, upper terminal, lower normal, and
lower terminal stator bar.
2. A process of simultaneous setting of upper and lower stator bars of a
turbo generator on a baking wagon during providing high voltage
insulation on the stator bars as substantially described and illustrated
herein with reference to the accompanying drawings.

A process of simultaneous setting of upper and lower stator bars of a turbo
generator on a baking wagon during providing high voltage insulation on the
stator bars, the process comprising the steps of adjusting a baking wagon for
upper type of stator bars; replacing three of the upper bars with 3 lug rest (9) of
the lower type stator bar; adjusting a supporting beam (5) for the upper type of
stator bar to have 3 lug rest of the Lower type and 3 lug rest of the upper type
stator bar; inserting a packing (8) below the lug rests (9) of the lower type stator
bars (1), the height of the packing (8) is such that it adjusts the co-ordinate 'H'
of the lower type stator bar on the supporting beam (5); and setting the Coordinate
'E' and 'L' for each of the lug rest (3,9) individually, the co-ordinate
position 'E' 'H' and 'L' being turbine side and exciter side length of upper normal,
upper terminal, lower normal, and lower terminal stator bar.