Basic Electrical Installation Work

| Kategorie: Kniha  |

Strana 233 z 399

Jak získat tento dokument?






Poznámky redaktora
waveform.2 shows transmission line steel pylon.1 Generation three-phase voltage.1. The prime mover not, course, simple crank handle, but steam turbine. Transmission Electricity generated the power station alternator kV. The heat required produce the steam may come from burning coal oil from a nuclear reactor.5cm diameter because they oper- ate very high voltage. Figure 11. The National Grid Network consists over 5,000 miles overhead alu- minium conductors suspended from steel pylons which link together all the power stations. Environmentalists say that these steel towers are ugly, but this method about times cheaper than the equivalent underground cable these high voltages. North pole South pole Grey Black Brown phase Rotating coil 120° 120° 120° Brown Voltage Time Black Grey Brown Black FIGURE 11. The generated voltage three identical sinusoidal waveforms each separated 120° shown Fig. generate electricity large modern power sta- tions using the same basic principle operation.Basic Electrical Installation Work 222 Generation, transmission and distribution of electricity Generation Figure 4. 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.5 Chapter shows simple a. generator alternator produc- ing a.c. Key Fact Information The individual conductors the National Grid Network are only about 2. Whatever the primary source energy is, only being used drive turbine which connected alternator, generate electricity. This electri- cal energy fed into transformer stepped very high voltage for transmission the National Grid Network 400 kV, 275 132 kV. Hot water heated until becomes superheated steam, which drives the vanes steam turbine which connected the alternator. However, place a single loop wire, the power station alternator has three-phase wind- ing and powerful electromagnets. . 11.c