The Naval Information Warfare Center
Pacific (NIWC Pac) is seeking sources for
the procurement of a 'Switching Transient
Study' which will be performed at Naval
Radio Transmitter Facility Jim Creek near
Arlington, Washington.
SCOPE:
The objective of the Transient Study is to
properly size the snubber on the secondary
(11.75 kV) side of each 2250 kVA voltage
regulator cyclo-converter transformers
feeding the port and starboard rectifiers of
an unknown transmitter device. The
location of a snubber on the secondary of
the transformer is unusual as they are
commonly placed on the primary of the
transformer to mitigate switching transients
created by upstream vacuum circuit
breakers (VCBs). The study will determine if
a snubber is necessary at this location and,
if the study results indicate a snubber is
needed, complete specifications for the
components shall be provided. If it is
determined a snubber is not required on the
secondary of the voltage regulator, the
application of a snubber on the primary side
(4.16 kV) of the voltage regulator shall be
examined in a similar way. The study shall
also include an insulation coordination study
to select the correct surge arrester for
application in parallel with the snubber at
this point of the electrical system.
A. Switching Transient Analysis Study –
EMTP
B. Double Power Factor & SFRA Field
Testing for two (2) 2-winding, 2250 kVA
voltage regulators cyclo-converter
transformer. If transformers are identical,
testing will only be required for a single unit.
DATA COLLECTION:
Due to the unusual application of this
snubber on the secondary of the
transformer, instead of more typically on
the primary directly downstream of VCBs
12T and 13T, a review of the snubber
application will be required. This shall
include conversations with NIWC Pac
personnel, review of supporting snubber
design documents, previous switching
transient study report, if any, and
explanation of how the system is currently
operated and switched. Additionally, if
NIWC Pac may be able to supply a SKM
model for the system, this will have much of
the data need for the present study.
After the review is completed, the
contractor shall request any additional
information/data needed to complete the
study.
