Reveres Power Protection., Theory & Setting .

khaled hamza

khaled hamza

@khaled-hamza-qmyNzA Oct 21, 2024
Reverse Power Protection., Theory & Setting .

Reverse Power Protection.










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1- Protection against overspend 32G (# 1).

In case of Turbine Failure, the Turbine is tripped and then the Generator is tripped by operation of reverse power relay to prevent overspending of the Turbine generator unit.


2- Protection against generator motoring 32G (#2).

-Generator motoring protection is designed for the prime mover or the system, rather than for the generator.

- With steam turbines, Turbines will overheat on low steam flow, motoring results from a low input To the Ac Generator,

- When This I/P can’t meet all the losses, the deficiency is supplied by absorbing real power from the system.

- since field excitation should remain the same , the same reactive power would flow as before motoring , thus, on motoring the real power will be into the generator, while the reactive power may be either flowing out or into the generator










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Setting of Reverse Power Relays


Data for setting calculations
-Rated Capacity of Generator -------- 440,000 KVA
-No Load Loss of Generator --------- 1,785 KW
-No Load Loss of Turbine ---------- 1,350 KW
-No Load Loss of TG unit ---------- 3,135 KW
-Permissible Motoring Time ------- 60 Sec.
-Relay Constant ------------------- 1 P.U. = Generator KVA






Setting Of Reveres Power Relay 32G ( #1 )


1- Reverse Power Trip Level


Trip Level < No load loss of TG unit * 0.3
= 3,135 * 0.3
= 940.5 KW
Pick up = Trip level / relay constant
= 941 / 440,000
= 0.0021 P.U.
Setting = - 0.002 P.U. ( 880KW )


2- Reverse Power Trip Delay


Trip Delay < Perm. Motoring time (60 Sec.)
Setting = 50 Cycles (1 Sec.)












Setting Of Reveres Power Relay 32G ( #2 )


1- Reverse Power Trip Level


Trip Level < No load loss of TG unit * 0.5
= 3,135 * 0.5
= 1,568 KW
Pick up = Trip level / relay constant
= 1,568 / 440,000
= 0.004 P.U.
Setting = - 0.004 P.U. ( 1,760KW )


2- Reverse Power Trip Delay


Trip Delay < Perm. Motoring time (60 Sec.)
Setting = 750 Cycles (15 Sec.)




<a href="https://science-hamza.blogspot.com" target="_blank" rel="nofollow noopener noreferrer">Electricity , Power generation ,Thermal power plant , Solar Energy , Generators , Green Energy</a>

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  • narayana murthy

    narayana murthy

    @narayana-z4W16q Dec 19, 2010

    ok but i had a doubt can we use the power by reversing the reverse current before coming to machine
  • khaled hamza

    khaled hamza

    @khaled-hamza-qmyNzA Dec 19, 2010

    Sorry , I can't understand the meaning of use the reversed power !!!, how can you want using this power ?
    I think reverse power is very harmful for the grid and big damage to the Steam Turbine Generator set.





    <a href="https://science-hamza.blogspot.com/" target="_blank" rel="nofollow noopener noreferrer">Electricity , Power generation ,Thermal power plant , Solar Energy , Generators , Green Energy</a>
  • narayana murthy

    narayana murthy

    @narayana-z4W16q Dec 19, 2010

    oh thats the problem ok i understood the problem thanks for post nice work buddy
  • khaled hamza

    khaled hamza

    @khaled-hamza-qmyNzA Dec 19, 2010

    at any time , i hope you really benefit from the article.





    <a href="https://science-hamza.blogspot.com/" target="_blank" rel="nofollow noopener noreferrer">Electricity , Power generation ,Thermal power plant , Solar Energy , Generators , Green Energy</a>

  • Harshad Italiya

    Harshad Italiya

    @harshad-ukH5ww Dec 19, 2010

    Interesting post Khaled. looking forward to see you active here.
  • khaled hamza

    khaled hamza

    @khaled-hamza-qmyNzA Dec 20, 2010

    Thank you so much , for your reply





    <a href="https://science-hamza.blogspot.com/" target="_blank" rel="nofollow noopener noreferrer">Electricity , Power generation ,Thermal power plant , Solar Energy , Generators , Green Energy</a>