NAESB Time and Inadvertent
Management Business
Practice
(TIMBP)
February 3 , 2009
Terry Bilke
Introduction
• Targeted business practice to address multiple
concerns in Order No. 693
• Originally submitted to NERC, NERC Staff and
Standards Committee rejected the SAR saying
Time Error Corrections (TEC) and Inadvertent
Payback are NAESB’s purview
• Relies on proven Time and Inadvertent
management practices, comparable to the WECC
automatic TEC
• No ERCOT/WECC impact unless they so choose
FERC’s Order No. 693 Concerns
• Address number and efficiency of TECs
• Concerned with frequency excursions
(nearly half of reported frequency excursions occurred during
TEC even though the East is in TEC 15% of the time)
• Wants NERC to reduce and penalize
large Inadvertent balances
• Asks NERC to investigate alternatives
to present TEC practices
Targeted Business Practice
• Draw on past practice
– Allow unilateral payback (greater of 5MW or 20% of
bias) when Inadvertent balance has same sign as
Time Error,
– Financial Settlement (MWs disclosed to NERC, terms
left to BAs)
• Uses Europe’s clock-day approach to TEC
– Wider window (30 seconds) will further reduce the #
of corrections and therefore excursions
– Better participation/effectiveness due to improved
awareness of TEC starts/stops
Option 2 Unilateral Payback is
the Cornerstone
• Unilateral Payback Option 2 >
Average Frequency closer to 60 Hz >
Less Inadvertent passing around >
Smaller Inadvertent Balances
Average Frequency closer to 60 Hz >
Fewer TECs>
Fewer Frequency Excursions
NERC BAC Drafting Team
Concern
• Identical Comments (potential small change
in calculated CPS1) were filed with WECC
WATEC
• The FERC dismissed these concerns in
Docket No. RM08-12-000 and agreed with
WECC
When balancing the slight loss of precision in CPS1
scores with the benefit of fewer manual time error
corrections, WECC does not believe the ultimate
impact of using the ATEC procedure is a threat to
reliability.
Key Points
• Under NERC’s old payback approach,
93 TECs / year
• Under current NERC payback method
(since 1997) 223 TECs/year
• NERC BAC proposed alternative
actually reduces today’s payback ability
by about 75% for a typical balancing
authority
TIMTF Recommendation
• Coordinated 6 month field trial
• Include a provision that only Balancing
Authorities with CPS1>120% may
participate in method 2 payback
• Field trial immediately stopped on any
reliability issues
• Report published by NERC Resources
Subcommittee
Proposed Implementation Plan
• Month 1/2
• Month 4
– Training
• Month 3
– Allow financial
settlement &
unilateral payback
(method 2)
– Widen window to 20
seconds
– Widen window to 30
seconds
– Longer corrections
• Month 5
– Clock-day
Corrections
• Month 6
– Draft Report
*NERC BAC team may want to test smaller offset