PHILADELPHIA - Engineers at Naval Ship Systems Engineering
Station (NAVSSES) completed installation and testing of a Digital Voltage
Regulator (DVR) on mine countermeasure (MCM) class ship USS Scout (MCM 8) May
30.
The new regulator provides sailors better control of the
Ship Service Diesel Generator's (SSDG) output voltage than the analog regulators
currently on MCMs, regardless of load fluctuations. Additionally, use of a DVR
to replace a nonfunctioning analog system saves the Navy more than $65,000 per
unit and cuts down on the readiness wait time by six months.
"The DVRs are better than the Analog Voltage Regulator
(AVR) because the parameters of the regulator can be preset to optimize control
of a specific generator without changing components," said Andy Guo, systems
electrical engineer with Steam, Diesel and Electrical Power Systems Branch at
NAVSSES. "In addition, the DVR has more built-in functions such as generator
protection features, programmable output relays, soft-start buildup, and
generator paralleling with either reactive droop compensation or cross current
compensation."
NAVSSES engineers developed the DVR design for the MCM
class, and they oversee the installation, validation, training and in-service
support. Guo said one of their goals was to meet the Navy's desire for
commonality. Other ship classes such as LSD 41, LSD 49 and LCC 19 have received
similar upgrades from analog regulators to DVRs - further reducing the Navy's
cost. The DVR is scheduled for installation on Wasp (LHD 1) class ships during
their mid-life upgrade availability.
Scout is the eighth MCM ship to receive the DVR, which
regulates the SSDG output voltage to the switchboard that powers the entire
ship. Guo said the first installation was in 2009 and the remaining ships in the
class are scheduled for upgrades by the end of 2018.
"The DVRs are located outside the switchboard, whereas the
old AVRs are located inside - making troubleshooting the DVR much easier since
the sailor no longer has to secure power to the entire ship to troubleshoot or
replace the DVR if an issue arises," said Guo. "All the parameters such as
voltage, current, power, and frequency can be viewed from the human-machine
interface (HMI) screen in front of the DVR enclosure. It certainly saves the
Navy time and money."
According to Guo, it took three years to go from design to
the first installation of the DVR. Installations take about five weeks and
testing another two weeks. Guo, who has been involved with the project since its
inception in 2005, added there have been minimal issues with the DVR system over
the past five years.
The Naval Ship Systems Engineering Station in Philadelphia
is the Navy's principal test and evaluation station and in-service engineering
agent for all hull, mechanical and electrical ship systems and equipment and has
the capability to test and engineer the full range of shipboard systems and
equipment from full-scale propulsion systems to digital controls and electric
power systems.