Exam Question
(a) Sketch a main engine shaft-driven generator arrangement with an electronic system for frequency correction (8)
(b) Describe the operation of the generator arrangement sketched in (a) (8)
ETO
ETO Exam papers
📅 Oct 2022
Reference Answer
(a)
(b) A shaft generator (SG) is a synchronous machine directly coupled to a vessel's propulsion shaft. Its speed, and thus the frequency of the generated AC power, varies with the engine's speed. To produce a constant frequency output, regardless of engine speed, the SG utilizes a static converter.
This converter comprises two main sections:
Rectifier: This section, typically a three-phase diode bridge rectifier, converts the variable-frequency AC output of the shaft generator into direct current (DC). A reactor smooths out the DC current.
(b) A shaft generator (SG) is a synchronous machine directly coupled to a vessel's propulsion shaft. Its speed, and thus the frequency of the generated AC power, varies with the engine's speed. To produce a constant frequency output, regardless of engine speed, the SG utilizes a static converter.
This converter comprises two main sections:
Rectifier: This section, typically a three-phase diode bridge rectifier, converts the variable-frequency AC output of the shaft generator into direct current (DC). A reactor smooths out the DC current.
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