Electric Power Systems

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Electric Power Systems Generation and
Delivery Presentation to ECE 1001 October 16,
2008 Tom Ferguson, P.E. 3M McKnight
Professor Dept. of Electrical and Computer
Engineering University of Minnesota, Duluth
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Topics

• Basic Power Systems
• Technologies, Equipment, and Jobs
• Reliability Keeping the Lights On
• The Future

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Basic Power System
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• Most electricity generated by use of fuel to
  produce steam
• Steam turns the blades of a turbine that spins a
  generator

• Rotating magnet in generator turns inside
  stationary coils of copper wire and generates
  flow of current

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High Voltage Transmission

• AC (mostly), DC
• Higher voltage, lower loss
• Three-phase
• Longer distances
• 115 kV and above
• 115 kV
• 138 kV
• 230 kV
• 345 kV
• 500 kV
• 765 kV
• Direct Current
• Forms bulk power system with generators

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Three-phase Power
Source Wikipedia
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ABB Core-type Power Transformer
Source httphowto.wikia.comwikiImageTransformer_e
lectric_symbol.svghttphowto.wikia.comwikiImageTran
sformer_electric_symbol.svg
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Mitsubishi Dead-tank HV Circuit Breaker

• Specifications
• Voltage (max) 245 kV
• BIL (kV crest) 900 kV
• Continuous Current 3000 A
• Interrupting Current 63 kA
• Interrupting Time 3 cycles
• Total Weight 6 tons
• Weight of SF6 201 lbs

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Air-insulated Substation (AIS)
FC
FB
FA
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ABB 550 kV Gas Insulated Substation (GIS)
Switchgear
SF6 24,000 times CO2 in 100 year Global Warming
Potential
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Distribution System

• Lower voltage
• 14 kV
• 23 kV
• 34 kV
• 69 kV
• Shorter distances
• Single and 3-phase
• Supplies loads
• Not designed for distributed generation

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Types of Electric Generation
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Renewable Energy
Source US EIA. Figures for 2006.
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Technologies, Equipment, and Jobs

• AC Apparatus
• DC/Power Electronics
• Protective Relaying
• Telecommunications
• SCADA and EMS
• (Supervisory Control And Data Acquisition)
• (Energy Management System)

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Reliability

• When your lights go out . . . just how bad is it?

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August 14, 2003

• Just after 4 pm EDT
• Largest blackout ever in US and Canada
• Affected 50 million people
• Two days to two weeks to restore
• 61,800 Megawatts of load lost
• Ohio, Michigan, NY, NJ, Connecticut,
  Massachusetts, Vermont, Ontario
• Cost 7 to 14 billion

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Other Major Disturbances

• March 18, 2000 New Mexico, 355,000 people
• June 25, 1998 Upper Midwest, Canada,
  152,000 people
• August 10, 1996 Western N. America, 7.5
  million people
• July 2, 1996 Western N. America, 2 million
  people
• July 13, 1977 New York City, 9 million
  people
• November 9, 1965 NE US, Ontario, 30 million
  people

Source NERC and FERC
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The Bulk Power System
Source NERC
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How the System Works

• Speed of Light (almost)
• One grid Rockies to the Atlantic
• Thousands of generators, all synchronized
• 100ks of miles of transmission lines
• Conversion between Chemical, Nuclear, Solar,
  Geothermal, Hydro and Electrical Energy
• Complex Controls and Communications
• . . . Designed under one set of rules . . .
• Now operated under a different set of rules

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Highly Complex, High Stakes

• New Challenges
• CO2 emissions, other emissions
• Distributed generation
• Renewable generation
• Transmission deficiencies
• Nuclear power rebirth
• Capital intensive, long planning horizons
• Convergence with transportation

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Why Its Attractive

• Reliable power supply is critical for
• Health and welfare
• Communities
• Local, state and national economies
• National security
• Great potential for breakthrough solutions
• International exposure work near home