If two alternators are operating in parallel synchronism and the excitation voltage of one machine is suddenly increased:
Direct Answer
Option C: Circulating reactive current flows and synchronising torque maintains synchronism
Increasing excitation on one alternator increases its generated EMF, driving a circulating lagging reactive current that produces demagnetizing armature reaction and synchronizing torque, preserving synchronism.
All Options
Detailed Explanation & Context
Increasing excitation on one alternator increases its generated EMF, driving a circulating lagging reactive current that produces demagnetizing armature reaction and synchronizing torque, preserving synchronism.
Relevant Framework: STCW 2010 Manila Amendments • DG Shipping E-Learning & Exit Exam Standards • High Voltage Safety Officer & Switchgear Operations (HV).
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