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POWER SYSTEM 2002 CONFERENCE -- IMPACT OF
DISTRIBUTED GENERATION
Interconnecting DER With Electric Power Systems
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Interconnecting DER with Electric Power Systems

• Existing IEEE Standards
• Standards Coordinating Committee 21
• IEEE Standard 929-2000 Recommended Practice
  for Utility Interface of Photovoltaic (PV)
  Systems
• Standards Coordinating Committee 23
• IEEE Standard 1001-1988 Guide for Interfacing
  Dispersed Storage and Generation Facilities with
  Electric Utility Systems
• Current IEEE Standards Work
• IEEE P-1547 Standard for Interconnecting
  Distributed Resources with Electric Power Systems

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Interconnecting DER with Electric Power Systems

• Definitions

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Interconnecting DER with Electric Power Systems

• P-1547 Project Approved in March 1999
• 4 - 6 meetings of Working Group per year since
  then
• Working Group Members
• More than 200 names on Working Group Roster
• 100 members attend each Working Group Meeting

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Interconnecting DER with Electric Power Systems

• Three Official IEEE Balloting Member Categories
• User
• The user is the person who will apply the
  standard when interconnecting DER to the electric
  power system. For example, the utility, the DER
  owner, etc.
• Producer
• The producer is the person who will apply the
  standard when producing equipment that will be
  interconnected to the electric power system. For
  example, equipment manufacturers, installers,
  etc.
• General Interest
• The general interest person is one who is
  interested, but not directly involved in
  interconnecting DER to the electric power system.
  For example, regulatory agencies, financial
  institutions, advocacy groups, etc.

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Interconnecting DER with Electric Power Systems

• Draft 7 circulated for ballot --- closing date of
  April 1, 2001
• Vote Results
• 66 Affirmative, not enough for approval (75
  required)

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Interconnecting DER with Electric Power Systems

• Draft 8 circulated for ballot -- closing date of
  October 2, 2001
• Vote Results
• 66 Affirmative, not enough for approval (75
  required)

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Interconnecting DER with Electric Utility Systems

• IEEE Standard 929
• Aimed at Photovoltaic Generator Systems, using
  solid-state inverters for interconnection
• Usually low kilowatt capacity
• Inverter inherently limits fault current
• Inverter tends to shut down automatically upon
  overload or reverse power
• IEEE Proposed Standard P-1547
• Intended to address DER without regard to prime
  mover (wind, fuel cell, etc)
• Attempts to address systems up to 10 Mw in size
• Seeks to provide universal solution

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Interconnecting DER with Electric Power Systems

• User Concerns
• Safety of Personnel
• Personnel must be able to work on the EPS and DER
  facility without undue risk of injury or death
• General public should not be exposed to hazardous
  conditions
• Fault duty, including DER, should not exceed
  ratings of distribution system equipment,
  including customer-owned equipment connected to
  the system
• Equipment damage, downed conductors, vault fires,
  etc.
• Normal load-carrying and interrupting
  capabilities, including DER, should not be
  exceeded
• Reduction of system reliability, premature
  failure of equipment
• Protective relaying and control equipment, should
  not be subject to mis-operation as a result of
  DER additions
• More and longer interruptions, high/low voltage
  problems

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Interconnecting DER with Electric Power Systems

• Producer and General Interest Concerns
• Interconnection costs must be minimal
• Interconnection equipment should be some fraction
  of the cost of the DER being connected.
• Utility involvement should be minimized
• Impact studies cost too much
• Some utilities use interconnection standards as a
  means of killing DER
• Interconnection must be simple so that it wont
  discourage DER applications
• Interconnection apparatus should be maintenance
  free as much as possible
• Interconnection operation should be automatic

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Interconnecting DER with Electric Power Systems

• Basic Problem
• Most Utility Electric Power Systems (EPS)
  were/are not designed to accommodate active
  generation and energy storage at the distribution
  level.
• Basic Need
• Develop technology and operational concepts that
  will enable realization of DR benefits while
  avoiding negative impacts on system reliability
  and safety

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Interconnecting DER with Electric Power Systems

• Significant Problem Areas
• Scaling
• My typical distribution feeder has a peak load
  of 4 Mw. Adding a few kW of PV is a whole
  different problem than adding 400 kW.
• Islanding
• Utility is still responsible for voltage and
  frequency of all its customer connections.
  Creating an island where some utility customers
  are supplied with un-controlled voltage or
  frequency is unacceptable
• Safety
• Personnel working on the distribution system MUST
  be protected from backfeed or accidental
  energization
• Protection System Design
• Radial distribution line protection is designed
  and coordinated for one way power flow.
  Bi-directional flow in some part or all of a
  feeder is a whole new world of problems
• Networked Distribution System
• Consideration postponed to future updates

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Interconnecting DER With Electric Power Systems

• Whats Next?
• Working Group meeting to discuss ballot results,
  possible resolution was held January 30-February
  1
• Writing Group to meet and attempt to resolve
  negative ballots received on Draft 8
• New Draft of P-1547 to be circulated for ballot
  before mid-year
• Still optimistic on submitting proposed standard
  to IEEE Standards Board before the end of 2002