Advantages of Polyphase System

Advantages of Polyphase System Points : Advantages of Polyphase System The A.C. systems discussed so far had only one circuit as in the case of 2 wire D.C. circuits in ac, systems it is possible tousle two, three or more individual circuits in the a des ice. These circuits operate at the same frequency, however their voltages and currents at out of phase from one another. Such systems are known as polyphase systems. The advantage of polyphase systems over single phase systems are:

1. Polyphase motors have a uniform torque whereas most of the single phase motors have a pulsating torque.
2. A polyphase transmission line requires less conductor material than a single phase line for transmitting the same amount of power at the same voltage.
3. Polyphase induction motors are self-starting and are note efficient. On the other hand single phase induction motors are not self-starting and are less efficient.
4. For a given frame size a polyphase machine gives a higher output than a single phase machine.