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Rated power [MVA] |
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Base (rated) electrical angular frequency [rad/s] |
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Net torque driving the shaft [N*m] |
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Developed Electric torque [N*m] |
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Mechanical (load) torque [N*m] |
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Inertia of all rotating masses |
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Rotor mechanical speed [rad/s] |
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Total number of poles for the machine |
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Damping coefficient |
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Rated mechanical speed [rad/s] |
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Per unit value indicator |
The net torque driving the shaft is given by;
and the relationship between electric and mechanical speeds is
Basic mechanical equation:
Rated torque (base torque),
The torque equation in per unit:
Where,
The per unit values in terms of the electrical speed is:
The inertia constant (H) of the rotating mass system is defined as the stored mechanical energy (E) per rated MVA:
Thus;
NOTE: Expressed in per unit, the mechanical speed and the electrical speed have the same value!
