Join 60,000+ competitive exam aspirants
What is the condition to derive Maximum Starting torque from Developed torque?
A) R2 = X2
B) Slip = 1
C) R2 = X2
D) Both S=1 and R2 = X2
Both S=1 and R2 = X2
The correct answer is D) Both S=1 and R2 = X2. This condition indicates that maximum starting torque occurs when slip is at its maximum value (1) and rotor resistance equals the rotor reactance.
The correct answer is D) Both S=1 and R2 = X2. This condition indicates that maximum starting torque occurs when slip is at its maximum value (1) and rotor resistance equals the rotor reactance.
TmaxтАЛтИЭR2тАЛ+jX2тАЛV2тАЛ тАФ Developed torque representation
S=NsтАЛNsтАЛтИТNrтАЛтАЛ тАФ Slip definition
When slip (S) is 1, it implies that the motor is at standstill, leading to maximum induced current and consequently maximum torque. The condition R2 = X2 signifies that the rotor resistance equals the rotor reactance, optimizing the torque developed at this slip.
Maximum torque is achieved at a slip of 1.
Balancing rotor resistance and reactance enhances torque output.
Provides high starting torque for heavy loads
Optimizes rotor dynamics for efficiency
Can lead to higher losses at high slip
Might cause overheating under prolonged operation
Used in applications requiring high starting torque
Applicable in cranes and elevators
Rotor resistance (R2) and reactance (X2) should be optimized for performance.
Option A is incorrect as it does not consider slip being equal to one.
D is correct тАФ Both conditions are necessary for maximizing starting torque.
Understanding the relationship between rotor resistance, reactance, and slip is vital in optimizing motor performance.