DRONACHARYA GROUP OF INSTITUTIONS, GREATER NOIDA
COURSE: B.TECH. VI SEM (A+B)
ASSIGNMENT – 1 (2012-13)
SUBJECT NAME: INTRODUCTION TO ELECTRIC DRIVES
SUBJECT CODE: EEC 604 BRANCH: EC
1. What is a Thyristor? How has this term been coined? Name the most popular
Thyristor?
2. What is the definition of Thyristor as per IEC?
3. Give the constructional details of side gate Thyristor. Sketch its schematic
diagram and the circuit symbol.
4. Define latching and holding currents as applicable to an SCR. Show these
currents on its I-V characteristics.
ASSIGNMENT – 2 (2012-13)
1. Explain various methods for protection of Thyristors.
2. Explain Resistance and Resistance Capacitance firing circuits with neat circuit
diagrams and waveforms.
3. Draw and explain the working of an UJT oscillator and its application in firing
circuit.
4. Discuss what would happen if gate is made positive w.r.t. cathode during the
reverse blocking of a Thyristor.
ASSIGNMENT – 3 (2012-13)
1. Give at least five applications of Phase-controlled rectifiers.
2. Power flow from 1-phase source to load R can be controlled through the use of
a thyristor. Discuss why this method is called phase-controlled converter.
3. Give at least two definitions of firing angle.
4. A single phase half wave converter is operated from 230V, 50 Hz source and
the load resistance is R=12Ω. For the firing angle delay of 30°, determine (a)
the rectification efficiency (b) form factor (c) voltage ripple factor (d)
transformer utilization factor (e) PIV of thyristor.
No comments:
Post a Comment