EE544 Distribution Systems

1
EE544 Distribution Systems

• Satish J Ranade
• Spring 2008

2
Distribution Systems

• Course Objective
• what every power engineer ought to know about
  distribution engineering !
• Overview of Distribution Systems
• Modeling, Analysis and Short-term Planning
• Engineering Issues Substations, Transformer
  Application, Protection, Power Quality
• Long term Planning Load Forecasting, Reliability

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Distribution Systems

• Texts/Reference/Resources
• H. Lee Willis Power Distribution Planning
  Reference Book, 2nd Ed., Marcel Dekker, New
  York,
• 2004
• T. A. Short Electric Power Distribution
  Handbook, 2nd Edition, CRC Press, Boca Raton,
  2003
• W. H. Kersting, Distribution Modeling and
  Analysis, 2nd Edition, CRC Press, Boca Raton,
  2006
• T. Gonen, Electric Power Distribution Handbook,
  2nd Edition, CRC Press, Boca Raton, 2007

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What is a Distribution System
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What is a Distribution System
Supplies customer Load from sub-transmission 4kV
34.5 kV ( maybe 69 kV) Radial Feeder Ability
to switch all or part to another source Single,
2- or 3 phase services
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What is a Distribution System
Supplies customer Load from sub-transmission 4kV
34.5 kV ( maybe 69 kV) Radial Feeder Ability
to switch all or part to another source Single,
2- or 3 phase services
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Requirements a Distribution System

• Obligation to Serve
• ANSI Service(ANSI C84.1-1995)
• Range A
• Nominal System Voltage 120
• Nominal Utilization Voltage 115
• Max. Service Voltage 126
• Minimum Service Voltage 114
• Minimum Utilization 110 V

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Requirements a Distribution System

• Regulated Rate of Return
• Conventional
• Customer Bill
• Generation Transmission DistributionExcess
  Fuel Cost
• Restructured Distco
• Distribution Energy

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Requirements a Distribution System

• Performance Requirements
• Reliability
• SAIFI customer interruptions/Total customers
• SAIDI sum of interruption durations/ Total
  customers
• ..
• Reported to PRC
• 10 (?) Worst feeders
• Penalties -- large value of index
• -- repeat worst feeders

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Keeping the lights on

• Minimum Cost Design
• Meet ANSI Service Reliability Critera
• ( Willis 2-Q Quantity and Quality)
• Minimum Cost Design
• Meet ANSI Service (Quantity)
• Quality case-by-case basis