AC power is used instead of DC
We (Usually all over the world), In all the countries, use AC voltage for consuming and for using electricity. Why not DC voltages?
It may ask you in an interview so it’s better to know it first.
There are some factors for using AC rather than DC.
- From the powerhouse/power plant, we produce AC voltages so it’s better to use AC rather than convert it from AC to DC (because there is extra no benefit to using DC). We need to change transformers, breakers, and other devices that we are using at the powerhouse.
- It is easy to maintain AC voltages and step up & step down AC voltages as compared to DC.
- The cost of power plants is much lower than the DC generation plant (transformers, circuit breakers, etc).
Why is AC used for long distance power transmission instead of DC?
It is more convenient to step up/down voltage for AC than for DC
Power wasted only depends on resistance and current in the circuit and does not depend on whether it is AC or DC.
If P is the power transmitted, and R is the resistance of the line:
Power loss = I2R = V2R
It is better to have a lower current and higher voltage to reduce losses. AC is much easier (therefore cheaper) to step up and down in voltage(using a transformer) than DC, and can be done more efficiently than the much more expensive and complex DC step-up/step-down systems. That is why AC is used for power transmission.