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When the excitation voltage is increased from 1 to 1.3 pu of a 3-phase synchronous motor. Then load angle for the constant power operation ________
must be increased
must be decreased
remain constant
Cant comment, need speed variation data
must be decreased
The correct answer is B (must be decreased) because increasing the excitation voltage in a synchronous motor leads to an increase in the generated EMF, causing the rotor to run ahead of the synchronizing torque. Thus, to maintain constant power, the load angle must be decreased.
The correct answer is B (must be decreased) because increasing the excitation voltage in a synchronous motor leads to an increase in the generated EMF, causing the rotor to run ahead of the synchronizing torque. Thus, to maintain constant power, the load angle must be decreased.
P=3тАЛVтЛЕIтЛЕcos╧ХтАЛ тАФ represents power in a three-phase system.
E=kтЛЕ╬жтЛЕ╧Й тАФ represents the electromagnetic force generated in a synchronous motor.
As the excitation voltage increases, the synchronous motor generates more active power, which requires an adjustment in the load angle to keep the motor stable and operating efficiently. Reducing the load angle helps in balancing the electrical and mechanical power requirements in the motor.
Increasing excitation increases the terminal voltage and power generation.
To maintain constant power output, the power angle must be adjusted accordingly.
Better voltage regulation with increased excitation.
Enhanced stability of operation under varying load conditions.
Over-excitation can lead to instability.
Higher losses due to saturation and heating effects.
Used in synchronous motors for power generation.
Applied in industrial drives requiring constant power outputs.
Standard excitation levels should be maintained for optimized motor performance.
Option A is incorrect as increasing the load angle could lead to instability, while option C is not applicable since the angle changes with excitation voltage.
B is correct тАФ as the excitation voltage increases, the load angle decreases for maintaining constant power.
Understanding the relationship between voltage, load angle, and power is crucial for optimal synchronous motor operation.