Reference no: EM13268389
Given a 3-phase 250 MVA 13.8 kV 60 Hz 24-pole 3phSM, Xd= 1.2ohm.
a. Determine the machine speed.
b. For operation at rated conditions, evaluate all stator phasors and draw the phasor diagram
for operation in the following modes...
generator; pf = 0.866 lagging
generator; pf = 0.866 leading
motor; pf = 0.866 lagging
motor; pf = 0.866 leading
c. For each mode in (a), determine the direction of P and Q flow (into or out of the 3phSM)
d. The 3phSM is used in a pumped storage application which has a head of 250 m. When pumping or generating, it operates at 84% efficiency, rated stator conditions. Determine the turbine flow when (1) generating and (2) pumping.
Why primary of power transformer will have excessive current
: Discuss why the primary of a power transformer would have excessive current if the secondary were short-circuited. Why would there be no voltage across the secondary if the primary is open. Explain how a transformer with a 1:1 turns ratio.
|
Explain the standard deviation value
: What percentage of tablets contain contain more than the standard amount of 250 mg acetaminophen per tablet? The mean value is 244.53mg and the standard deviation value is 11.88
|
Classify the system as to stabilty and time-invariance
: A system is described by the differential equation ty'(t)-8y(t)=x(t). Classify the system as to linearity, time-invariance and stability. A system is described by the equation y(t)= Intergral x(lamda)d(lamda) (from t/3 to infinte). Classify the sys..
|
Compute the atomic mass of the metal
: An unknown metal is found to have a density of 19.300g/cm^3 and to crystallize in a body-centered cubic lattice. The edge of the unit cell is found to be 0.28864nm. Calculate the atomic mass of the metal
|
Determine the turbine flow when generating stator
: The 3phSM is used in a pumped storage application which has a head of 250 m. When pumping or generating, it operates at 84% efficiency, rated stator conditions. Determine the turbine flow when (1) generating and (2) pumping.
|
Calculate the height from which the ball is released
: It takes 2.80 s for a small ball with a mass of 0.060 kg released from rest from a tall building to reach the ground. Calculate the height from which the ball is released
|
What is the yield on a three-year bond one year from today
: According to the expectations theory of the term structure. if interest rates are expected to be 2%, 2%, 4%, and 5% over the next four years, what is the yield on a three-year bond one year from today?
|
Find the current through the 200-ohm resistor
: a) Find the current out of the current source. b) Find the current through the 200-ohm resistor. c) Calculate the power delivered by the source.
|
Calculate the uncertainty in position of the electron
: An electron and a 140-g baseball are each traveling110m/s measured to a precision of 0.055%. Calculate the uncertainty in position of the electron
|