1. The document provides instructions for synchronizing a thermal power plant generator to the grid. Key steps include checking that isolators and instruments are ready, testing excitation equipment, matching the generator's voltage and frequency to the grid using the automatic voltage regulator and speeder gear, and closing the generator breaker when the synchroscope needle indicates the proper phase to connect safely.

1. THERMAL POWER PLANT
OPERATIONS
Simulator Part 6- Day 4
MANOHAR TATWAWADI
Director, tops
A2-806, PALLADION, BALEWADI, PUNE 411045
Mob: 9372167165, Email:-mtatwawadi@gmail.com

2. SYNCHRONIZATION
1. Check with Grid Control Room that the isolators of the HV
side of the generator Transformer breaker are closed
position.
2. All CTs and PTs of the grid are in service in the 220KV
switchyard.
3. The thyristor blocks, rectifier transformer and associated
equipment for the excitation system is tested and OK.
4. Stator water cooling system, Seal oil system, Hydrogen
cooling systems are running and ok.
5. All protections are reset and put in service.
6. Generator overspeed test shall also be taken if the unit is
being synchronised after an annual overhaul of the unit.
7. Boiler is ready for increase in load/fuel.

3. SYNCHRONISATION
8. After attaining 3000 RPM, turbine speed governor should
take over control and observe that the speeder gear has
reduced to about 80%.
9. Main Steam Stop valves should be fully open and Speed
control should be done by speeder gear.
10. Maintain the turbine speed at 3000rpm with the help of
speeder gear from Panel 8 (Generator Desk).
11. Close field breaker from Panel 8.
12. Switch on “field & flashing supply” from panel 8.
13. Gradually raise the generator voltage by increasing
excitation voltage manually to near rated voltage 15.75Kv.
14. When the voltage reaches the rated voltage, turn off Field
flashing supply off.

4. GENERATOR DESK
CONTROL PANEL 8
GENERATOR DESK

5. STATIC EXCITATION EQUIPMENT
To Unit Xformer

6. SYNCHRONISATION
15. Match the AVR voltage error and put AVR in Auto mode.
16. Switch on the synchroscope from panel 8(Generator
Desk).
17. Check the Grid system voltage on Panel8 (Generator Desk)
18. Check the Grid system Frequency on Panel 8.
19. Match the voltage of incoming machine with the system
voltage by AVR excitation manual control.
20. Match the frequency of incoming machine with the system
frequency by speeder gear control.
21. Keep the incoming machine voltage & frequency slightly
higher than the system voltage & frequency.

7. SYNCHRONISATION
22. Observe that the needle of the synchroscope is rotating
slowly in clockwise direction.
23. If the needle is stationary, speed of the incoming machine
is to be adjusted by speeder gear control so that the
needle is rotating slowly in clockwise direction.
24. Close generator breaker when the needle is just
approaching the mark by correct phase on synchroscope
(12 O'colck position) and light of 'synchronisation in limit'
is lit above synchroscope.
25. Take a load of 10-12 MW immediately by speeder gear
control.
26. Switch off the synchroscope.