Tutorial EEC 2 - Admission/Application Essay Example

Other (s) ial EEC 2 Question Force on the conductor per unit length=F/L= IB sin α F/L=400N/mQuestion 2(a) The maximum flux through the coil= Φ= BA cos θ Φ =0.05T X20000mm2 cos 900=1000cos θ=0(b)When the 100mm sides are inclined at 450, Φ =0.05T X20000mm2 cos 450=1000cos = θ=1.0 x103WbQuestion 3E = vBl = (80km/hr x 1 hour/3600 sec x 1000 meters/km) x (40 x 10^-6 T) x (2.0 meters) emf generated in the axle of the car = 1.77 x 10^-3 VoltsQuestion 4 Peak voltage of the input supply =2. ×. RMS. V.

=2 x 230=560Volts while mean load voltage =) V average= ______2Vm _____ πQuestion 5 (a)(b) V mean= 2Vs/ αQuestion 6For  120 degrees, the SCR output attributes will change positively and the voltage of the ac line will become zero.Question 7 Semi-converter circuitQuestion 8For Φ=150 degrees, the output attributes of semi-converter circuit in question 7 such as the polarity of the load voltage may change.Question 9 In the questions above, if the thyristors were replaced with diodes, the expression of the output voltage will be given in terms of the line to line input voltage as:Question 10 Reversible transistor operated H-bridgeThyristors can perform the same operation by triggering a voltage waveform that changes the direction of the motor rotation.

Question 11In the absence of flywheel diode any change in the quadrant beyond 30° will result in a sudden voltage increase that leads to uncontrolled speed and torque.Question 12Question 13Question 14If the control circuit is an SCR based full converter, the variables in question 12 and question 13 would change by permitting control over larger currents through the means of small gate current.Question 15 Motor torque= =Question 16Question 17If the circuit in question 15 and question 16 was a semi-converter, the output voltage would be discontinuous and the circuit will have higher harmonic content in the supply current waveforms and load voltage.

Question 18 The above circuit is expected to enable a motor to perform a 4 quadrant mode of operation including motoring down, motoring up, regenerating up and regenerating down. The relationship between speed and torque during the operation is that an increase in speed will result in an increase in torque (Rashid 45).Question 19Natural commutation refers to the process of turning off thyristors without the use of any external circuits. On the other hand, forced commutation involved the use of external components/circuits when turning off a thyristor.

Works CitedRashid, Mark H. Power Electronics: Circuit, Devices, and Applications, Third edition. New York: Pearson Prentice Hall, USA, 2004. Print.