project maker
04-08-2014, 10:07 AM
INSULATION AND MANUFACTURING PROCESS OF
600MW TURBO GENERATOR BARS
Introduction
As the complete one peace coil is not practicable so the coils are manufactured in two parts,
upper and lower bars. Out of the various BLOCKS as mentioned before the coil and
insulation manufacturing block is BLOCK-4. This block is known as the COIL AND
INSULATION MANUFACTURING block. Block-4 is a feeder block for insulating items,
winding with class-B Bituminous insulation and sheet metal components for all the products
of Block-1 i.e. Turbo-generators, Hydro-generators, A.C. and D.C. machines. There are three
BAYS in this block each bay manufactures stator bars and coils for different machines as
mentioned below:
. Inter Strand Short test: -
The consolidation bar stack is tested for the short between any two conductors in the bar,
if found then it has to be rectified. This is done to ensure that no local current is flowing
due to short circuit between conductors. (300V A/C supply).
For this test all the bare conductors at both the ends are separated from each other so
that they do not short circuit. Then a live wire is connected to a conductor and received
from it consecutive conductor to light a lamp. Hence if the lamp lights up it shows short
circuit between the two conductors due to improper insulation between them. It shows
insulation failure between the conductors, these conductors are then replaced and bar is
followed through all the previous processes. Similarly all the conductors are checked for
any short circuit. After passing both the half bars from I.S.T. the bars are combined
together and pressed into a single bar. A sheet of mica glass insulation is provided
between the two halves as the insulation also has some gluing property to consolidate the
two halves into a single bar. All the steps of pressing are again followed for the complete
bar and then it is allowed to cool.
7. Forming: -
In heavy generators each stator coil is very large in size and hence its manufacturing is
difficult as it will be very difficult to handle and process the complete coil. So each coil is
manufactured in two halves i.e. Upper half and Lower half. The bars which are processed
till this process are straight and hence they are required to be formed into the upper half
or the lower half. Hence this process of forming is very important as in this process the
bars are bending from both the ends of the bar i.e. at exciter side and turbine side at
specific angles and shape as per design.
This process is done manually. First the former is set according to the design making
different angles at different positions. Each bar of a variant is bent or formed at same
angle. Once the former is set, the bar is mounted on it and formed manually by melleting
it from both the ends.
After forming the formed portion of the bars are assumed to get loose creating air
gaps between the conductors due to such a heavy melleting. Thus the formed portion of
the bar are clamped at different places and provided with heaters to reconsolidate the
formed portion. After few hours the bar is then allowed to cool at room temperature.
Introduction:
Bay 2 is the manufacturer of stator bars of hydro generators, stator coils of AC motors and
stator coils of DC Exciter. The stator coils of AC motors of up to 11 KV, stator bars of Hydro
generators of 200 MW and DC Exciters of all the 500 MW THRI generators are
manufactured in this bay.
Conductor Tapping
The copper conductor is first provided with two layers of insulation, this is also known as
double layer tapping. The insulation tape used in this is Micafabriglass Tape. In this process
the copper drums are loaded on the stand and tapping rolls on taping heads of the Tapping
machine. The copper conductor is insulated with two layer of tape in butt as per design and
hence the insulated copper conductor is again rolled on the drum from other side of the
machine. The insulation on the copper is checked, which is provided by the automatically
moving tapping rolls with some tension.
CONCLUSION
The second phase of training has proved to be quite faithful. It proved an opportunity for
encounter with such huge machines like turbo-generator hydro generator etc.
The architecture of B.H.E.L., the way various units are linked and the way working of
whole plant is controlled make the students realize that Engineering is not just structural
description but greater part is planning and management. It provides an opportunity to learn tech.
Used at proper place and time can save a lot of labor.
However, training has proved to be satisfactory. It has allowed us an opportunity to get an
exposure of the practical implementation of theoretical fundamentals.
600MW TURBO GENERATOR BARS
Introduction
As the complete one peace coil is not practicable so the coils are manufactured in two parts,
upper and lower bars. Out of the various BLOCKS as mentioned before the coil and
insulation manufacturing block is BLOCK-4. This block is known as the COIL AND
INSULATION MANUFACTURING block. Block-4 is a feeder block for insulating items,
winding with class-B Bituminous insulation and sheet metal components for all the products
of Block-1 i.e. Turbo-generators, Hydro-generators, A.C. and D.C. machines. There are three
BAYS in this block each bay manufactures stator bars and coils for different machines as
mentioned below:
. Inter Strand Short test: -
The consolidation bar stack is tested for the short between any two conductors in the bar,
if found then it has to be rectified. This is done to ensure that no local current is flowing
due to short circuit between conductors. (300V A/C supply).
For this test all the bare conductors at both the ends are separated from each other so
that they do not short circuit. Then a live wire is connected to a conductor and received
from it consecutive conductor to light a lamp. Hence if the lamp lights up it shows short
circuit between the two conductors due to improper insulation between them. It shows
insulation failure between the conductors, these conductors are then replaced and bar is
followed through all the previous processes. Similarly all the conductors are checked for
any short circuit. After passing both the half bars from I.S.T. the bars are combined
together and pressed into a single bar. A sheet of mica glass insulation is provided
between the two halves as the insulation also has some gluing property to consolidate the
two halves into a single bar. All the steps of pressing are again followed for the complete
bar and then it is allowed to cool.
7. Forming: -
In heavy generators each stator coil is very large in size and hence its manufacturing is
difficult as it will be very difficult to handle and process the complete coil. So each coil is
manufactured in two halves i.e. Upper half and Lower half. The bars which are processed
till this process are straight and hence they are required to be formed into the upper half
or the lower half. Hence this process of forming is very important as in this process the
bars are bending from both the ends of the bar i.e. at exciter side and turbine side at
specific angles and shape as per design.
This process is done manually. First the former is set according to the design making
different angles at different positions. Each bar of a variant is bent or formed at same
angle. Once the former is set, the bar is mounted on it and formed manually by melleting
it from both the ends.
After forming the formed portion of the bars are assumed to get loose creating air
gaps between the conductors due to such a heavy melleting. Thus the formed portion of
the bar are clamped at different places and provided with heaters to reconsolidate the
formed portion. After few hours the bar is then allowed to cool at room temperature.
Introduction:
Bay 2 is the manufacturer of stator bars of hydro generators, stator coils of AC motors and
stator coils of DC Exciter. The stator coils of AC motors of up to 11 KV, stator bars of Hydro
generators of 200 MW and DC Exciters of all the 500 MW THRI generators are
manufactured in this bay.
Conductor Tapping
The copper conductor is first provided with two layers of insulation, this is also known as
double layer tapping. The insulation tape used in this is Micafabriglass Tape. In this process
the copper drums are loaded on the stand and tapping rolls on taping heads of the Tapping
machine. The copper conductor is insulated with two layer of tape in butt as per design and
hence the insulated copper conductor is again rolled on the drum from other side of the
machine. The insulation on the copper is checked, which is provided by the automatically
moving tapping rolls with some tension.
CONCLUSION
The second phase of training has proved to be quite faithful. It proved an opportunity for
encounter with such huge machines like turbo-generator hydro generator etc.
The architecture of B.H.E.L., the way various units are linked and the way working of
whole plant is controlled make the students realize that Engineering is not just structural
description but greater part is planning and management. It provides an opportunity to learn tech.
Used at proper place and time can save a lot of labor.
However, training has proved to be satisfactory. It has allowed us an opportunity to get an
exposure of the practical implementation of theoretical fundamentals.