In later half of eighties, in nineteenth century, it was proposed to have a power system with 3- phase, 50 Hz A.C generation, transmission and distribution networks. Once a.c system was adopted, transmission of large power (MW) at higher transmission voltage become a reality by using transformers. Level of voltage could be changed virtually to any other desired level with transformers – which was hitherto impossible with D.C system. Nicola Tesla suggested that constructionally simpler electrical motors (induction motors, without the complexity of commutator segments of D.C motors) operating from 3-phase a.c supply could be manufactured. In fact, his arguments in favor of A.C supply system own the debate on switching over from D.C to A.C system.