STUPIDSID
1 (a)
How a constant v/f control is superior to the stator voltage control?
5 M
1 (b)
Give the performance comparison of VSI and CSI.
5 M
1 (c)
Discuss the different factors for selection of baterry for UPS.
5 M
1 (d)
Give the comparison between dual converter operating in non circulating and circulating current mode.
5 M
2 (a)
With the help of circuit diagram and associated waveforms, explain the principle of operation of type C chopper.
10 M
2 (b)
Explain multiple pulse width modulation as used in PWM inverters.
10 M
3 (a)
Explain with neat the slip power recovery technique to control the speed of 3 phase slip ring induction motor above an below the synchronous speed. State the advantages of this technique.
10 M
3 (b)
Explain with neat diagram and waveforms the operation of flyback converter.
10 M
4 (a)
A separately exicted D.C. motor operating from a single phase half controlled bridge rectifier at a speed of 1400 rpm. has an input voltage of 330 sin 314 t and a back emf of 80V. The SCR's are fired symmetrically at ?=30° in every half cycle and the armature has a resistance of 4Ω. Calculate the average armature current and the motor torque.
10 M
4 (b)
Discuss the working of load commulated chopper with associated voltage and current waveforms. Show voltage variation across each pair of SCR's as a function of time.
10 M
5 (a)
Explain with neat diagram and waveforms the working of parallel inverter. What is the need for feeback diodes and pulse train for firing of SCR's.
10 M
5 (b)
Describe the working of a single phase full conveter fed separately excited D.C. motor with circuit diagram, relevant waveforms and expressiors.
10 M
6 (a)
Explain with neat diagram the static rotor resistance control method for the speed control of 3 phase induction motor.
10 M
6 (b)
Explain the effect of source inductane on the performance of a single phase fully controlled converter and derive the expression for the output voltage.
10 M
Write short notes on any two:
7 (a)
Control strategies employed in chopper for operating the switches.
6 M
7 (b)
IR compensation.
7 M
7 (c)
Mc Murry Inverter.
7 M
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