The torque load that a synchronous motor can handle is dependent on the hold-in strength of the poles. Hence, to increase the hold-in torque, it is necessary to __________.
• Synchronous motor torque and how it relates to the strength of the rotor magnetic field • Effect of field excitation (DC current to rotor) on pole strength and hold-in torque • Relationship between armature current, power factor, and pull-out/hold-in torque
• Think about what physically makes the rotor stay in step with the rotating magnetic field: is it stronger or weaker rotor magnetism? • Which action would directly increase the magnetic strength of the rotor poles themselves, not just change stator conditions? • Consider which options would make it easier for the motor to resist being pulled out of synchronism under heavy load.
• Identify which choice directly strengthens the rotor magnetic field (pole strength) • Check whether changing armature (stator) current primarily affects load and power factor rather than rotor pole strength • Verify how adjusting a field rheostat affects the amount of DC current flowing in the rotor field winding
No comments yet
Be the first to share your thoughts!