Dynamic Transfers WECC MIC Meeting The Last Hurrah! Hollywood, CA Oct 13, 2011 Bob

Dynamic Transfers

WECC MIC Meeting“The Last Hurrah!”

Hollywood, CAOct 13, 2011

Bob

Dynamic TransfersWECC MIC MeetingOctober 13, 2011

Dynamic Transfers

• There are two types:– Dynamic Schedules– Pseudo-Ties

• For the purposes of this presentation, we are considering a traditional bilateral world.


Dynamic Schedules

• Proposed NERC definition:– A time-varying energy transfer that is updated

in real time and included in the Net Interchange Scheduled term in the same manner as an Interchange Schedule in the affected Balancing Authorities’ control ACE equations (or alternate control processes).

• Typically used in the Southwest


Pseudo-Ties

• Proposed NERC definition:– A time-varying energy transfer that is updated

in real time and included in the Net Interchange Actual term in the same manner as a Tie Line in the affected Balancing Authorities’ control ACE equations (or alternate control processes)

• Typically used in the Northwest


ACE Equation

Area Control Error =

(NIA - NIS) – 10β(FA - FS) – (other stuff)

Net Interchange Actual

Net Interchange Scheduled


Common Items

• Both types use a dynamic transfer signal

• Both type apply the signal to certain ACE equation components

• Both types require transmission arrangements from Source to Sink

• Both types support “capacity with energy up and down” transactions


UnCommon Items

• Various services maybe required by “host” or “Native” BA for dynamic schedules but not necessarily for pseudo-ties.

EMS 1

M

EMS 2

Interchange or Tie-Line MeteringApplied to both ACE equations’ NIA but with opposite signs


EMS 1

M

EMS 2

M

Dynamic Schedule for LoadDynamic Signal applied to both ACE equations’ NIS but with opposite signs


EMS 1

M

EMS 2

M

Pseudo-Tie for LoadDynamic Signal applied to both ACE equations’ NIA but with opposite signs


EMS 1

GM

M

EMS 2

Dynamic Schedule for GenerationDynamic Signal applied to both ACE equations’ NIS but with opposite signs


EMS 1

GM

M

EMS 2

Pseudo-Tie for GenerationDynamic Signal applied to both ACE equations’ NIA but with opposite signs



e-Tags and Dynamic Transfers• The tag is just a front, a representation, a place-

holder• Dynamic Schedule e-Tags do not impact

Scheduled Interchange before the fact or in real-time

• The tag does not control the dynamic MWs so e-Tag curtailments will not on their own limit or change the dynamic transfer signal

• Dynamic Schedule e-Tags will impact after-the-fact Scheduled Interchange values, so ATF adjustments are needed


What is DSS?• Dynamic Scheduling System – a special

infrastructure to facilitate multiple shorter-term deals

• The DSS e-Tag “programs” or sets-up the communications and other aspects of the deal

• The tag does not control the dynamic MWs• e-Tag curtailments are respected by DSS • DSS provides the after-the-fact Scheduled

Interchange values


DSS on 1 Day

EMS 1

EMS 2

EMS 3

DSS

BA1 is supplying capacity with energy changeable within the hour to both BA2 and BA3 via the DSS


DSS on Next Day

EMS 1

EMS 2

EMS 3

DSS

Both BA1 and BA2 are supplying capacity with energy changeable within the hour to BA3 via the DSS


And DSS Next Quarter

EMS 1

EMS 2

EMS 3

DSS

BA3 is supplying capacity with energy changeable within the hour to both BA1 and BA2 via the DSS


What are Dynamic Transfer Limits?

• Amount of MW transfer determines the receiving end voltage

• For large transfers, voltage management is critical to system reliability

• Can impact automatic and manual switching of reactive devices and Remedial Action Scheme arming


What are Dynamic Transfer Limits?

∆V

∆P

receiving end voltage

transferred power

∆V

∆P


Want More?• NERC Dynamic Transfer Reference

Guidelines June 2010• Dynamic Transfer Capability Task Force

Phase 1 Report on ColumbiaGrid web site• Sharon Helms for DSS information• Out for comment, revised WECC INT draft

criterion for Dynamic Transfers• In 2013, revised NERC INT standards


Documents

Dynamic Transfers WECC MIC Meeting The Last Hurrah! Hollywood, CA Oct 13, 2011 Bob