classification of Transmission system ?

The various transmission and distribution systems can be listed in a tabular form as given below :

Transmission Systems

1. DC Systems

    1. DC 2 Wire

    2. DC 2 Wire with Mid-point Earthed

    3. DC 3 Wire

2. AC Systems

    1. Single Phase

        1. 1 ph 2 Wire

        2. 1 ph 2 Wire with mid-point earthed

        3. 1 ph 3 Wire

    2. Two Phase

        1. 2 ph 3 Wire

        2. 2 ph 4 Wire

    3. Three Phase

        1. 3 ph 3 Wire

        2. 3 ph 4 Wire

Note: In practice, the 3 phase 3 wire AC system is universally adopted for transmission.