In Power Angle Curve, Question arises How Electrical Output Power is more than Mechanical Input Power?
In equal Area Criteria it is mentioned that Area under Power Angle Curve during Acceleration is equal to that during Deceleration. i.e. Energy stored is equal to Energy Released. How Area under Power Angle Curve is Energy?
In this Video we have used Torque Angle Curve to answer these Questions. It is similat to Power Angle Curve. However Power Angle Curve is easy to understand.
Power = 3EVsin(delta)/Xs. Dividing it by Angular Velocity we get Torque Angle Curve.
Net Torque is equal to Applied Mechanical Torque Tm - Opposing Electromagnetic Torque Te. If Net Torque is positive, there is acceleration, Angular Velocity increases and Load Angle increases.
If Net Torque is Negative, there is deceleration, Angular Velocity decreases and Load Angle decreases.
Based on it, it is seen that the Region between 0 to 90 degree is stable and between 90 to 180 Degree is unstable.
When Te is Positive, it is Generator Region and Te opposes Rotation. If Te is Negative, Te aids the Rotation and it is Motor Region.
When Fault occurs, Te becomes Zero, there is Acceleration and Load Angle increases to Delta 1. At Load Angle Delta 1, Fault clears and Te becomes greater than Tm. There is deceleration. However, Omega R is still gretaer than Omega S. Load Angle keeps on increasing till Omega R is equal to Omega S.
Area A1 under Torque Angle Curve duringAcceleration is called Area of Acceleration. Area A2 during deceleration is called Area of Deceleration.
During Acceleration Energy is stored and during Deceleration Energy is released.
Since Energy stored is equal to Energy released, these Areas are Equal.
The Question is where is the Energy going during Fault. It is stored as Kinetic Energy of Rotor. Angular Velocity of Rotor increases. After a Fault is cleared Stored Energy in Rotor is released to Generator Output.
Негізгі бет Torque Angle Curve
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