Question
Download Solution PDFA three-phase star-connected synchronous alternator of rating 22 kVA, 20 kV, 50 Hz has synchronous reactance of 8 per phase. The induced voltage per phase is 20 kV and the line terminal voltage is 15 kV. Find the 3-phase maximum power of the machine.
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFConcept
The 3ϕ power in an alternator is given by:
\(P = {3V_pE_p \over X_s}sinδ\)
For maximum power, δ = 90°
\(P_{max} = {3V_pE_p \over X_s}\)
per-phaseHere, all values must be per-phase values.
Calculation
Given, \(V_L=15\space kV\)
\(P_{max} = {3\times 15\times 20 \over 8}\)
Pmax = 112.5 MW
Option 2 is correct.
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