 Interconnecting DER With Electric Power Systems POWER SYSTEM 2002 CONFERENCE -- IMPACT OF DISTRIBUTED GENERATION Image

 ©ABB Ltd. Page 2 Interconnecting DER with Electric Power Systems Existing IEEE Standards Standards Coordinating Committee 21: IEEE Standard Recommended Practice for Utility Interface of Photovoltaic (PV) Systems Standards Coordinating Committee 23 IEEE Standard 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

 ©ABB Ltd. Page 3 Interconnecting DER with Electric Power Systems Definitions:

 ©ABB Ltd. Page 4 Interconnecting DER with Electric Power Systems P-1547 Project Approved in March 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

 ©ABB Ltd. Page 5 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.

 ©ABB Ltd. Page 6 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)

 ©ABB Ltd. Page 7 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)

 ©ABB Ltd. Page 8 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

 ©ABB Ltd. Page 9 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

 ©ABB Ltd. Page 10 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 won’t discourage DER applications Interconnection apparatus should be ‘maintenance free’ as much as possible Interconnection operation should be ‘automatic’

 ©ABB Ltd. Page 11 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

 ©ABB Ltd. Page 12 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

 ©ABB Ltd. Page 13 Interconnecting DER With Electric Power Systems What’s 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