Paper format. National Examinations, December 2019 —
16-Elec-B8 Power Electronics and Drives. Three hours; closed book with one
double-sided aid sheet; an approved Casio or Sharp calculator. Five questions
constitute a complete paper and all questions are of equal value, so each carries
20 marks. All a.c. voltages and currents are rms unless noted otherwise; for
three-phase circuits voltages are line-to-line and power is total real power
unless noted otherwise. Every question is solved below, in the exam's own order.
Reference texts.
- M. H. Rashid, Power Electronics: Circuits, Devices and Applications,
4th ed. — the primary reference for this exam code (thyristor statics ch. 7,
a.c. voltage controllers ch. 11, d.c. choppers ch. 5).
- N. Mohan, T. M. Undeland and W. P. Robbins, Power Electronics: Converters,
Applications and Design, 3rd ed. — switching-converter analysis and
d.c.–d.c. converter waveforms.
- C. W. Lander, Power Electronics, 3rd ed. — a compact treatment of
phase control and of the chopper current equations used in Question 5.
- B. K. Bose, Modern Power Electronics and AC Drives, and R. Krishnan,
Electric Motor Drives: Modeling, Analysis and Control — for the drive
context behind Questions 3 and 4.
- J. J. Grainger and W. D. Stevenson, Power System Analysis — for the
radial-feeder and three-phase load calculations of Questions 1 and 2.
