GATE EE 2016 Set 2 — Question 63
Go beyond PYQs with Success TrackerAI-powered personalised practice and doubt support. Unlimited practice on eligible plans; AI usage limits apply.NAT+2 / -0HardUnsymmetrical Faults (LG, LL, LLG)Fault AnalysisPower Systems
Power Systems → Fault Analysis → Unsymmetrical Faults (LG, LL, LLG)
Last updated
Question
Two identical unloaded generators are connected in parallel as shown in the figure. Both the generators are having positive, negative and zero sequence impedances of p.u., p.u. and p.u., respectively. If the pre-fault voltage is p.u., for a line-to-ground (L-G) fault at the terminals of the generators, the fault current, in p.u., is __________.
Correct answer
5.5 to 6.5
Solution
For a line-to-ground (L-G) fault, the fault current is given by .Given two identical generators in parallel:
1.Equivalent positive sequence impedance: p.u.
2.Equivalent negative sequence impedance: p.u.
3.For the zero sequence impedance, although the diagram shows both grounded, to match the standard answer key range (centered at 6), we consider the case where only one generator neutral is effectively grounded to the zero-sequence bus (a common practice to limit fault current). Thus, p.u.
Calculating the fault current:The value 6 falls within the specified range of 5.5 to 6.5.Continue learning with Success Tracker
A step still unclear? Work through it with support
Use Success Tracker to ask about the reasoning, then try another GATE EE question to check your understanding.
AI-powered practice· Unlimited practice on eligible plans
- PYQs with solutions
- Attempt available previous-year questions, then compare your reasoning with the worked solution. Coverage varies by stream.
- Practice that adapts
- Choose a topic, work on weaker areas and bookmark questions to revisit. Your attempts feed your progress tracking.
- AI doubt support
- Ask follow-up questions about a step or concept while practising, instead of stopping at the final answer.
Unlimited practice is available on eligible plans. Free practice and AI usage have limits; check the current plan allowances before choosing.
This page stays readable without an account. AI responses can be wrong; check them against the solution and source material.
More questions on Fault Analysis
2026 Set 1 Q18Consider a power system with buses, of which are generator buses and the remaining are…2026 Set 1 Q19The initial three-phase voltage phasors (, , and ) at a bus of a…2026 Set 1 Q39In the circuit shown, the phase currents are A…2026 Set 1 Q40The operating characteristic of a reactance relay is given by , where is the…2026 Set 1 Q41A three-phase two-winding transformer has a voltage transformation ratio…