1. Tutorial on Power Distribution Circuits G. Heydt Arizona State University March, 2003

2. What is power distribution ? Power systems are made up of: Generation Transmission Distribution Generation systems are the large generating units that produce AC voltages at high power levels. Transmission systems are long distance, very high power level systems to transmit power from city to city. Distribution systems are local, lower power systems that take power from the intercity grid and bring this to residences, commercial customers, and industrials

3. Typical numbers

4. Typical configurations Transmission systems are NETWORKED usually. That is there are many loads and many sources, and many lines that join these points in a mesh, networked fashion. FLAGSTAFF PRESCOTT PHOENIX TEMPE NOGALES WINSLOW HOLBROOK

5. Typical configurations Transmission systems are networked so that power can be delivered between load centers by several routes. If a line is removed from service, power can be rerouted. Like power delivered to Nogales from Flagstaff by two different routes. FLAGSTAFF PRESCOTT PHOENIX TEMPE NOGALES WINSLOW HOLBROOK

6. Distribution systems Distribution system configuration is usually different -- rather than being networked, distributuin systems are usually RADIAL. That means lines go from A to B to C to D to... RURAL RDPRICE RDMESA-WMESA-CMAIN ST

7. Distribution systems Power can only flow in one direction in the radial system RURAL RDPRICE RDMESA-WMESA-CMAIN ST

8. Distribution systems Why is this configuration used? Safety (only one source direction - when it is interrupted, the line is dead) Cost -- it is cheaper Easy to locate problems RURAL RDPRICE RDMESA-WMESA-CMAIN ST

9. But there are advantages of reliability of networked systems - provided cost, safety, control, and maintenance issues can be resolved.

10. A TYPICAL RADIAL DISTRIBUTION SYSTEM

11. Research and study areas The reliability vs cost of networked systems versus radial systems Use of networked systems (they do this in big cities like Chicago and New York) Control of power in a networked distribution system

12. Directed reading Some easy to read texts on distribution engineering:

13. Acknowledgements To my colleagues and students who are working on the project To Dr. Momoh at the NSF To the staff at ONR for their input