Question

What is the reason for choosing 3-phase ac systems as opposed to 6-phase for example?

Answer 1

the main reasons for choosing 3- phase system instead of 6-phase system are

1. more complexity in operation of 6-phase system i.e. it requires more circuit breakers, more bus bars for coupling in substation, difficulty in design of transformer, complexity in design of transmission towers, more clearance required for transmitting power in 6-phase system.

2. it’s not economical in operation and maintenance

3. in 3-phase system a double circuit on same transmission tower can carry power but in 6-phase system it is very difficult to place double circuit on one transmission tower.