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Calculate Generator Mechanical Energy

  1. Aug 2, 2011 #1
    I have a huge generator 2.5MW and I need to calculate the mechanical energy (kinetic energy) it contains when it is running at rated speed (2975 R/min).

    How can I do that and I quantities do I need ?

    My goal is to relate how much electric energy the generator produces as depending on its mechanical energy.
  2. jcsd
  3. Aug 2, 2011 #2
    The rotational kinetic energy is:

    KE = 1/2 * I * w^2

    I = moment of inertia of rotating assembly

    w = angular velocity = 2975 rpm

    Hopefully, the generator manufacturer can tell you what 'I' is. If not, you will have to estimate.

    Check units when calculating result.
  4. Aug 2, 2011 #3
    Generator Mechanical system has something called the H-constant. Its values lies between 5 and 10.
    H-constant = Kinetic Energy / Machine MVA
    So, in your case, Kinetic Energy = 2.5 * (5 to 10) Mega joules.
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