1. POLY PHASE A.C.CIRCUITS
CHAPTER 7

2. CONTENTS 1. Generation of Poly phase Voltages, Phase Sequence
2. Star or Wave (Y) connection - Values of Phase currents, Voltages in star and delta connection

3. Polyphase System
Phase means branch, circuit or winding while poly means many.
So such applications need a supply having many a.c voltages present in it simultaneously.
Such a system is called polyphase system.

4. Generation of Single phase voltage system

6. Generation of Three phase voltage system

7. Three Phase Alternator

9. Generation of Three phase voltage system

10. Generation of Three phase voltage system

11. Phase Sequence
The sequence in which the voltages in three phases reach their maximum positive values is called Phase Sequence. Generally the phase sequence is R-Y-B.

12. Line Voltage & Line Current
The potential difference between any two lines of supply is called LINE VOLTAGE and current passing through any line is called LINE CURRENT.

13. Line Voltage & Line Current
In Star connection

14. Line Voltage & Line Current
In Delta connection

15. Phase Voltage & Phase Current
The potential difference between any line and neutral of supply is called PHASE VOLTAGE and current passing through any phase is called PHASE CURRENT.

16. Phase Voltage & Phase Current

17. Phase Voltage & Phase Current

18. END