Q5. a) State the conditions, which must be satisfied before an a.c. generator can be paralleled with live bus bars. (8)
b) After an a.c. generator has been paralleled explain how the following are achieved for the incoming generator
i) correct kW load sharing. (4)
ii) correct load current when the generator has power factor different to the other generators. (4)
Q1. (a) Sketch a circuit diagram for an automatic voltage regulator illustrating how the A.V.R. utilizes a silicon-controlled rectifier to control the excitation system for an alternator. (10)
(b) Describe how the A.V.R. monitors output and controls the excitation system. (6)
Q2. a) In A.C. generators, voltage dip occurs in two stages.
i) Sketch a voltages-time graph showing the pattern of voltage dip. (4)
ii) Referring to this graph, state the reasons the effect on the electrical system of a small power installation when a large load is suddenly switched on. (4)
b) Explain EACH of the following categories of voltage control:
i) Error operated (4)
ii) Functional (4)
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