Three phase system is universally employed for a generation, transmission and distribution of electric power. There are several reasons for why three-phase systems are more commonly used over higher phase (four phase or six phase) systems. Simply we can say that a three phase system is more efficient over other phase systems.
The reason for choosing three phase is dependent on the percentage of increase of output power on increasing the number of phases. Let us check how much the power increase.
- If a two-phase system is employed in a machine the output of the machine increase by 41.4% over the single phase system.
- If a there phase system is used, 50% increase is observed in the output of the machine.
- If the number of phases in increased from three to a large number, the increase in output is only 7%. And it will cause complication.
- Considering the power output, three phase system is more economical over higher phase systems.
- Two phase supply and six-phase supply, when required, is obtained from 3 phase supply.
Hence, three phase systems are most commonly used over higher phase systems.