Assignment-II -Subject-Electrical Machines

Assignment-II
Synchronous Motor & Power Devices

Subject_ Electrical Machines

SET-A

1) Draw and explain Equivalent Circuit and Phasor Diagram of a Synchronous Motor at lagging power factor. 

2)Write applications of 3-ph synchronous motors.Also Compare 3-ph synchronous motors with 3-ph Induction motors.

3) Explain Operation with 3-phase Synchronous motor  constant load and variable excitation  with suitable phasor diagram and graph.

4) Explain Operation of 3-phase Synchronous motor with constant excitation and variable load.

5)Write power and torque equation of synchronous motor

6) A 50 HP 410 V 50 Hz 3 phase star connected synchronous motor has full load efficiency of 85%. The synchronous impedance of the motor is (0.2 + j 2.0) Ω per phase. If the excitation of the motor is adjusted to give leading p.f. of 0.85. Calculate : i) Full load induced emf line value.ii) Mechanical power developed.

7)Explain construction detail and V-I characteristics of TRIAC.

8)Explain and draw output and Transfer characteristics of MOSFET and IGBT.

9)Based on application and construction distinguish SCR and TRIAC

Assignment-II

Synchronous Motor & Power Devices

Subject_ Electrical Machines

SET-B

1) With suitable voltage equation of Synchronous motor draw and explain Equivalent Circuit and Phasor Diagram of a Synchronous Motor at lagging power factor. 

2)With suitable diagram explain working of 3-ph

 synchronous motors also write applications of 3-

ph synchronous motors.

3) Explain 'V' curves and inverted 'V' curves in case of three phase synchronous motor.

4) Explain Operation of 3-phase Synchronous motor with constant excitation and variable load.

5) The efficiency of 3-phase , 400V star connected synchronous motor is 95% and it takes 24A at full load unity power factor. what will be induced emf and total mechanical power developed at full load and 0.9 power factor leading? The synchronous impedance of the motor is (0.2+2j) ohm/phase.

6)Draw and explain power flow in synchronous motor

7)  Explain construction detail and V-I characteristics of DIAC.

8) Explain Construction details and draw output and Transfer characteristics of IGBT.

9)  Explain construction detail, application and V-I characteristics of SCR.

10)Based on application and construction distinguish DIAC and TRIAC