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22-Elec-B7 Power Systems Engineering: December 2017

Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)

  1. Question 1 Long transmission line — ABCD constants, sending-end conditions and power-factor correction
  2. Question 2 Armature reaction, reactive-power capability and the round-rotor operating table
  3. Question 3 Single-phase transformer — primary quantities, efficiency and regulation
  4. Question 4 Bus types, fast-decoupled power flow, and a three-bus solution
  5. Question 5 Short-circuit consequences, transformer protection, and a mid-line three-phase fault
  6. Question 6 Line-to-line fault at the mid-point of a line — fault current and phase voltages
  7. Question 7 Transient stability under a sustained fault — equal-area criterion

Start with Question 1 →

Paper format. National Exams, December 2017 — 16-Elec-B7 Power Systems Engineering, 3 hours, open book, any non-communicating calculator permitted. The paper prints seven problems; the rubric states that any five questions constitute a complete paper and that all questions are of equal value, so only the first five in the answer book are marked. All seven are worked here, because this set is a study resource rather than a sitting. Sub-part point values are reproduced from the paper.

Reference texts. This exam code follows M. E. El-Hawary, Electrical Power Systems: Design and Analysis (IEEE Press) — the notation used below is his: the long-line ABCD constants of Problem 1, the round-rotor power-angle relations of Problem 2, the cantilever transformer equivalent of Problem 3, the power-flow injection equations of Problem 4, the network-reduction fault analysis of Problems 5 and 6, and the equal-area criterion of Problem 7. Corroborating references: J. D. Glover, M. S. Sarma and T. J. Overbye, Power System Analysis and Design, 6th ed. (ch. 5 transmission lines, ch. 6 power flow, ch. 7–9 symmetrical components and unsymmetrical faults, ch. 11 transient stability); J. J. Grainger and W. D. Stevenson, Power System Analysis; and S. J. Chapman, Electric Machinery Fundamentals, 5th ed. (ch. 2 transformers, ch. 4–5 synchronous machines). Canadian practice references for the protection and grounding discussion: CSA C22.1 Canadian Electrical Code, Part I and the relevant IEEE C37 and C57 series.