The document provides a comprehensive overview of a synchronous generator with a capacity of 250 MW, detailing its historical milestones, technical specifications, cooling and sealing systems, excitation methods, grid synchronization procedures, protection schemes, and testing methods. It emphasizes the importance of stability, efficiency calculations, and ongoing research and development in optimizing generator performance. The presentation concludes with references for further reading on turbo generators and related topics.

1. Synchronous Generator
BPSCL 2X250 MW IPP
SHYAM SUNDAR ROY
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2. Presentation outline
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 Introduction
 Historical Milestone
 Technical Data
 Constructional Overview
 Cooling System
 Seal Oil System
 Excitation System
 Capability Curves
 Grid Synchronization
 Protections & Tripping
 Generator’s Tests
 Efficiency and Losses
 Research & Development
 References

3. Basics
 Synchronous : Rotor and RMF rotate with
same speed.
 Generator: Convert rotational mechanical
energy into electrical energy.
 Governed by Fleming’s right hand rule
 Operation based on Faraday’s laws of EMT.
 Emf Equation: 4.44Kc Kd ɸ Z
 Induced emf = -ɗɸ / ɗʈ
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4. 1866-83
• Designed by Ganz Works
• Dynamo Gen Production started
for hydro power
1887
• DC dynamo based Turbo
generator designed
• Engaged in Thermal Power Plants
1901
• Supplied first industrial turbo
generator
• Installed in Eberfield, Germany
Chronological Aspects
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5. Technical Data
BHARAT HEAVY ELECTRICALS LIMITED
TURBOGENERATOR
TYPE: TG-HH-0250-2 PO.NO-10281-A-131-01
10282-A-131-01
3 Phase 50Hz YY PF: 0.85Lag
294.1 MVA 250MW
16.5KV 10291A 3000RPM
Coolant : Hydrogen Spec: IS-5422 IEC-34
Gas Pressure: 4KSC Insulation Class: F
Excitation Voltage: 300V, Current : 2497A
Division : Haridwar Year: 2010
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6. Constructional Overview
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 STATOR
• Stator frame
• Stator core
• Stator winding
• End cover
• Bushings
• Terminal box

7. Construction Contd…

 ROTOR
• Rotor shaft
• Rotor winding
• Rotor ring
• Field connection
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8. Cooling System
 STATOR WINDING: Indirectly Hydrogen Cooled ROTOR WINDING: Directly Hydrogen Cooled
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Design data for H2 cooler Value Units
Hydrogen pressure 4 Kg/cm2
Gas Flow 33 m3/ min
Heat dissipating capacity 2650 KW
Cold gas temperature 45
o
C
Hot gas temperature 75
o
C
Gas pressure drop 600 pa
Cooling water flow 280 m3 /hr
Max i/l water temp 38
o
C
Water o/l temp 46.50
o
C
Water pressure drop 10.50 mmwc

9. Cooling Contd…
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10. Seal Oil System
Design Data Value Units
Oil Flow 7.8 m3/ hr
Heat dissipating
Capacity
100 KW
Oil Inlet temp 70 oc
Oil outlet temp 43 oc
Oil Press drop 0.15 Bar
Cooling Water flow 17.4 M3/hr
Max i/l water temp 38 oc
Water o/l temp 43 oc
Water press drop 0.15 mmwc
 Major Components
 Seal oil storage tank(in bearing drain line)
 Seal oil vacuum pump
 Intermediate oil tank
 Downstream pump pressure controller
 Seal oil coolers
 Seal oil filters
 Differential pressures control valves
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11. Sealing Contd…
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12. Excitation System
 Brushless Excitation
 Static Excitation
 Main Components
 Pilot exciter
 Main exciter
 Rectifier wheel
 Automatic voltage regulator
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13. Brushless Excitation
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14. Excitation Contd..
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15. Capability Curves
 Limiting factors are rotor and stator thermal
limits
 Under excited limiting factor is stator end iron
heat.
 Excitation control setting control is
coordinated with steady-state stability limit
(SSSL)
 Minimum excitation limiter (MEL) prevents
exciter from reducing the field below SSSL
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16. Curves Contd…
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17. System Stability
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18. Stability Contd…
 Graphical technique used to examine
the transient stability of the machine
systems (one or more than one) with an
infinite bus.
 Stability conditions are stated by
equating the two area segments which is
present in the power angle diagram.
The KE stored during acceleration is
mentioned as A1, and the KE stored
during deceleration is mentioned
as A2. PA becomes zero when it has both
decelerating power and accelerating
powers.
This criterion method helps to
determine the greatest limit on the load
without affecting the stability limit.
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19. Mathematical Approach
 The equation governing the rotor motion is
given by Swing equation.
 A Synchronous generator is driven by a prime
mover.
 power exchange between the mechanical
rotor and the electrical grid due to the rotor
swing.
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20. Grid Synchronization
 In order to synchronize a generator to
the grid, four conditions must be met:
 Phase Angle
 Frequency
 Voltage Magnitude
 Phase Sequence
 More info on given link
 https://www.youtube.com/watch?v=FI_0
7YVS3tY
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21. Phase Angle
 The phase angle between the
voltage produced by the generator and
the voltage produced by the
grid must be zero.
The phase angle (0 to 360°) can be
readily observed by comparing the
simultaneous occurrence of the peaks
or zero crossings of the sinusoidal
waveforms.
At that instance (Figure 4 below), the
pointer on the synchroscope would
indicate 12:00 o'clock.
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22. Frequency
The frequency of the sinusoidal voltage
produced by the generator must be equal to
the frequency of the sinusoidal voltage
produced by the grid.
 If generator’s frequency were than grid.
The synchroscope would be rotating rapidly
counter clockwise. If the generator breaker
were to be accidentally closed, the generator
would be out of step with the external
electrical system. It would behave like motor
and the grid would try to bring it up to speed.
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23. Frequency Contd…
If the generator were faster than the grid
the rotor and stator would be slipping poles and
possibly destroy the generator.
If the generator breaker were to be closed at
this time, the grid would pull the generator into
step.
If the generator breaker were to be closed at
this time, the grid would pull the generator into
step.
This would cause a large current in-rush to
the generator and high stresses on the
rotor/stator with subsequent damage to the
generator If the generator were leading the grid.
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24. Voltage Magnitude
 The magnitude of the sinusoidal voltage produced by the generator must be equal
to the magnitude of the sinusoidal voltage of the grid.
 If the generator voltage is higher than the grid voltage, this means that the
internal voltage of the generator is higher than the grid voltage. When it
is connected to the grid the generator will be overexcited and it will inject MVAR.
 If the generator voltage is less than the grid voltage, this means that the
internal voltage of the generator is lower than the grid voltage. When it is
connected to the grid the generator will be under-excited and it will absorb MVAR.
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25. Phase Sequence
The phase sequence of the three
phases of the generator must be the
same as the phase sequence of the
three phases of the electrical
system (Grid).
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26. Protections Schemes
 Generator Differential protection
 Generator Stator E/F(0-100%)
 Backup Impedance Protection
 Reverse Power Protection
 Gen Under voltage Protection
 Loss of Excitation Protection
 Gen Pole Slipping Protection
 Generator Dead M/C Optd
 Rotor E/F Stage-2 Optd
 Gen Over Voltage Protection
 Negative Phase Sequence Protection
 Gen Under Frequency protection
 Gen Over Frequency Protection
 GRP-1&2 Relay Faulty
 Over Fluxing Protection
 186A/286A Relay Faulty
 186B/286B Relay Faulty
 Generator DC Supply Fail protection
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27. Tripping Logics
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28. Generator
Tests
Electrical Tests
Open circuit test
Short circuit test
High voltage test
Inter stand test
Mechanical Tests
Vibration test
Temperature test
 NDT test
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29. Major Losses
 Core loss
 Copper loss
 Windage loss
 Friction loss
 Diode drop loss
 Restive loss
 Thermal loss
 Counter Emf
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30. Efficiency Calculation
 Efficiency = Output energy / Input energy
 ɳ = 1/ Heat Rate
 ɳ = Output / output +losses
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31. Research & Developments
 In the field of electromagnetic, the focus lies on highly precise prediction of the
electromagnetic and thermal data to optimize generator parameters, efficiency and
size.
 R&D focuses are on new and improved design concepts, precise vibration and
noise analysis.
 Cooling optimization needs precise ventilation design tools, including heat transfer
calculations with modern CFD (computational fluid dynamics) and CHT (conjugate
heat transfer) methods.
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32. References
 Literatures
 A text book of Turbo generator, NPTI Publications
 A text book of Machines Protections, NPTI Publications
 BHEL Haridwar Internal material
 Websites
 http://www.bhel.com
 http://www.cea.nic.in/
 http://www.cpri.in/index.php
 http://en.wikipedia.org/wiki/Turbo_generator
 http://en.wikipedia.org/wiki/Hydrogen-cooled_turbogenerator
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33. Thank You !
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