4 ms·
There aren't any mathematical tricks, rather how the real world (generator) translates to math. The generator at the power company has 3 stators that are on eq
by andmarios 9y ago
There aren't any mathematical tricks, rather how the real world (generator) translates to math.
The generator at the power company has 3 stators that are on equal distance between each other on a circle.
As the rotor rotates, it induces AC voltage at each of them.
Because the rotor rotates at a stable speed, the AC voltage follows a sine function.
Because the stators are placed 2/3pi apart, their sine waves have a phase difference of 2/3pi.
Because 2/3pi+2/3pi+2/3pi=2pi, if you add them all together then you get 0 (sin[2pi]=0) and this is your neutral wire.
Quite honestly I learned that very late in the university which is a pity.
Once you see how the real world translates to math, many things (like euler's formula which is of utmost importance for engineers) fall in place.
- femto 9y agoExpanding on this: because the neutral current is close to zero, the conductor for the neutral current has looser requirements on its impedance. With perfectly balanced phases the neutral conductor can be eliminated, saving money and material. In practise, the Earth itself gets used as the neutral conductor. This is why one sees three wires in transmission lines and not four. Incidentally, the closely spaced multiple wires within each conductor of an electrical transmission line, typically held apart by spacers, act to reduce the inductance of the transmission line, which reduces losses. The little "dumbbells" which are on each side of each tower, are vibration dampers to reduce metal fatigue.
- phasetransition 9y agoTypical large generators will have between 12 and 24ph (in multiples of three). They're split out in triplets 120 degrees apart. If you see 12+ phases out in the wild, you're probably close to a power plant.