20110318PAC to Staff 16-18.pdf

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~ROCKY MOUNTAINPORA DISI Of PAFI RECEIVED
20n MAR' 8 AM 10: 2'
March 17,2011
Neil Price
Idaho Public Utilities Commission
472 W. Washington
Boise,ID 83702-5918
RE: ID PAC-E-11-6
IPUC Production Data Requests (16-18)
20 I Sout Main, Suite 2300
Salt Lake City, Utah 8"! iII
Please find enclosed Rocky Mountain Power's responses to IPUC Production Data Requests 16-
18.
If you have any questions, please feel free to call me at [phone].
Sincerely,
Ji T ru tv4/~ /~
J. Ted Weston
Manager, Regulation
Enclosure
C.c.: Jean JewelllPUC (3 copies)
~
PAC-E-11-6/Rocky Mountan Power
March 17,2011
IPUC Production Data Request 16
IPUC Production Data Request 16
Would automation of capacitor bans address voltage excursions?
Response to IPUC Production Data Request 16
Yes, however, there are some limitations. Voltage excursions will occur as long
as large blocks of load are switched OFF and ON. The duration and magnitude of
the voltage excursion can be controlled by the size of the load changes and how
quickly voltage control devices react to the changes.
Recordholder:
Sponsor:
Carol Hunter
Carol Hunter
.
PAC-E-11-6/Rocky Mountain Power
March 17,2011
IPUC Production Data Request 17
IPUC Production Data Request 17
Is it cost effective to fully automate the switching of capacitor bans? Please
provide any analysis to support the response.
Response to IPUC Production Data Request 17
The estimated cost to automate enough capacitor bans to minimize the problem
is $200,000. This is the cost to automate nine capacitor bans on five circuits out
of four substations. This wil not completely resolve the problem, please refer to
the Company's response to IPUC Production Data Request 16.
Recordholder:
Sponsor:
Carol Hunter
Carol Hunter
PAC-E-11-6/Rocky Mountain Power
March 17,2011
IPUC Production Data Request 18
IPUC Production Data Request 18
Would phasing or "stair-stepping" curlments address the voltage excursion
problem? If so, what would be the minimum amount of time between phases to
maintain voltage reguation?
Response to IPUC Production Data Request 18
The Company began "stair-stepping" curailments during the 2010 irrigation
season. It was in response to voltage excursion problems in 2009 when too much
load was removed from the system all at the same time. The Company set the
steps to occur roughly thee minutes apart. The three minutes allowed the
substation and line-type regulators time to adjust the voltage and not exceed
Company flcker stadards (3%). For the most part, it worked well. One of the
complications of this effort was to find loads that could be stepped OFF or ON
that also worked with customers. Unfortately, due to the excess load, the
Company had to star this process at 7:00 am which defeats the purose of the
program, which is to reduce the Company's system peak.
Recordholder:
Sponsor:
Carol Hunter
Carol Hunter
.