Page 15 - Power Electronic Control in Electrical Systems

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Power electronic control in electrical systems 7

a

d axis
θ
q axis

rotation

b c

Fig. 1.2 Schematic diagram of a synchronous machine.

d axis
q axis
r F
L FF
r a
v a i F
v F
i a
L QQ
L DD
L aa
r Q
r D
i Q
L bb L cc
i D
r c
v c
r b
i c
v b
i b
Fig. 1.3 Coupled windings of a synchronous machine.

desired reference voltage are compared to produce a voltage error which is used to
alter the exciter output. Generally speaking, exciters can be of two types: (1) rotating;
or (2) static. Nowadays, static exciters are the preferred choice owing to their higher