generate electricity large modern power sta-
tions using the same basic principle operation. Whatever the primary source energy is, only being
used drive turbine which connected alternator, generate
electricity.
The National Grid Network consists over 5,000 miles overhead alu-
minium conductors suspended from steel pylons which link together all the
power stations.
Key Fact
Information
The individual conductors the
National Grid Network are only about
2. The
prime mover not, course, simple crank handle, but steam turbine.
Transmission
Electricity generated the power station alternator kV. However, place a
single loop wire, the power station alternator has three-phase wind-
ing and powerful electromagnets.c. generator alternator produc-
ing a.2 shows transmission line steel
pylon. This electri-
cal energy fed into transformer stepped very high voltage
for transmission the National Grid Network 400 kV, 275 132 kV. Figure 11. Environmentalists say that these steel towers are ugly, but
this method about times cheaper than the equivalent underground
cable these high voltages. The generated voltage three identical
sinusoidal waveforms each separated 120° shown Fig.Basic Electrical Installation Work
222
Generation, transmission and distribution of
electricity
Generation
Figure 4.1
Generation three-phase voltage.1.5 Chapter shows simple a.
North pole
South pole
Grey Black
Brown phase
Rotating
coil
120°
120°
120°
Brown
Voltage
Time
Black Grey Brown Black
FIGURE 11. waveform.
These very high voltages are necessary because, for given power, the
current greatly reduced, which means smaller grid conductors and the
transmission losses are reduced. 11.
Hot water heated until becomes superheated steam, which drives the
vanes steam turbine which connected the alternator.c.5cm diameter because they oper-
ate very high voltage. The heat
required produce the steam may come from burning coal oil from
a nuclear reactor.
