Please show a complete solution to the problem 6. A 540 V, 50 Hz, 3-phase circuit takes 31 A at a lagging power factor of 0.88. A synchronous motor is used to raise the power factor to unity. Calculate the numerical value of the power factor, in per unit, of the synchronous motor when driving a mechanical load of 7.7 kW. The motor has an efficiency of 85%. Give your final answer in 3 decimal places.   Correct Answer:  0.550 ± 0.001

Q: 500 KW loading power factor 0.6 is lagging. The combined power factor 0.9 is to be used by the…

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Q: A 50-HP 400-volt 12-pole 60-Hz wye-connected 3-phase synchronous motor has armature resistance of…

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Q: At what speed will a four-pole three-phase motor operate at when supplied with 60 Hz? A. 1800 RPM…

A: We know synchronous speed Ns = (120 * f)/P Given f=60 hz   Poles P=4 Ns = (120 * 60)/4 Ns = 1800…

Q: A 300-Vo, 60-Hz, three-phase induction motor is drawing 20 A at 0.75 PF lagging. The stator copper…

A: Power input of a 3-phase induction motor can be expressed as : Pin= VinI.pfwhere,Vin= Input voltageI…

Q: A three phase induction motor runs on 60 Hz power line at 1070 rpm at full load. The motor has one…

A: synchronous speed of the motor can be calculated using the following relation N =120fP

Q: Comment briefly on the relationship between input and output power at varying excitation levels and…

A: Infinite Bus Bar is the bus bar where many(infinite)  synchronous machines are connected.  The…

Synchronous Motor

The synchronous motor is an AC electric type motor where at a steady-state the shaft rotation is synchronized with the supply current variable-frequency. To an integral number of AC cycles, the rotation period is exactly equal. The stator of the motor in the synchronous motor contains multi-phase AC electromagnets due to which a magnetic field is created that rotates in time with the oscillation of the line current. The rotor contains a permanent magnet and the rotor rotates in synchronization with the stator field at the same rate and provides the second synchronized magnetic field which is rotating in nature as a result. When the synchronous motor is supplied with independently excited multi-phase AC electromagnets on both the rotor and the stator, it is termed as a doubly-fed machine. The most widely used AC-type motors are the synchronous AC motor and the induction AC motors.