Question
Download Solution PDFA 400 V, 30 kVA, single-phase alternator has an effective armature resistance of 0.3 Ω. An excitation current of 20 A produces 266 A armature current on short-circuit and an EMF of 400 V on open-circuit. The synchronous impedance and synchronous reactance of the alternator are, respectively, ________.
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFConcept
The synchronous impedance is calculated using the open-circuit voltage and the short-circuit current:
where, Voc = Open circuit voltage
Isc = Short circuit current
The synchronous reactance of the alternator is given by:
Xs = Synchronous Reactance
Zs = Synchronous impedance
Ra = Armature resistance
Calculation
Given, Voc = 400 V
Isc = 266 A
Ra = 0.3 Ω
Xs = 1.46 Ω
Last updated on Jun 16, 2025
-> SSC JE Electrical 2025 Notification will be released on June 30 for the post of Junior Engineer Electrical/ Electrical & Mechanical.
-> Applicants can fill out the SSC JE application form 2025 for Electrical Engineering from June 30 to July 21.
-> SSC JE EE 2025 paper 1 exam will be conducted from October 27 to 31.
-> Candidates with a degree/diploma in engineering are eligible for this post.
-> The selection process includes Paper I and Paper II online exams, followed by document verification.
-> Prepare for the exam using SSC JE EE Previous Year Papers.