Download Determining Least Replacable Units

Modular Power Conversion
Cabinet for Future Warships
Anna V Brinck- Graduate student, University of Wisconsin-Milwaukee
Robert M Cuzner- Assistant Professor, University of Wisconsin-Milwaukee
Introduction
• Next generation Navy Ships will have high power electric weapons
and sensors and are trending towards medium voltage DC (MVDC)
power systems
• Novel power conversion solutions are required to accommodate
these diverse power requirements and see to the challenges
presented in power conversion such as reliability, high power pulsed
loads, and safety.
• Power conversion devices, in addition to being safe and reliable, need
to stay within volume, mass and cost constraints.
Ship Power System Overview
• 4 to 6 zone layout
• Zones divided into left and right (Port and Starboard)
• Each zone has 3 to 4 tiers of power conversion, each requiring its own
power conversion cabinet design
PMM
PGM
PCM1B
• Redundancy of cabinets in case of
damage to part of the ship
PFM
MMC
PORT
MMC
ISOS
SST
NPC
PDM
PCM1A
ZONE 1
ZONE 2
ZONE 3
ZONE 4
STERN
ISOP
SST
BOW
INV
IPNC
RECT
INV
BUCK
STARBOARD
Whole ship zonal layout
TO
PORT
FROM
PORT
IPOS
ISOC
DC/DC
ABT
ABT
ABT
Converter cabinets in half zone
ZONE
Modular Power Conversion Cabinet
Specifications
IPNC
• The Integrated Power Node Center (IPNC) is a power
conversion cabinet with two inputs and 6 outputs
440VAC
50A
• Two possible DC inputs, one from within the same
ship zone and one that can be routed from an adjacent
ship zone in case of an emergency
LOADS
15A
OUTPUT 1
440VAC/60Hz
15A MAX
VARIABLE RESISTANCE
LOAD
15A
OUTPUT 2
440VAC/60Hz
8A MAX
VARIABLE IMPEDANCE
LOAD
15A
OUTPUT 3
440VAC/60Hz
10A MAX
NON-LINEAR LOAD
115VAC
OUTPUT 4
115VAC/400Hz
1: 3 PH 10A
2: 1PH 3A
3: 1 PH 2A
4: 1PH 1A
115/
200VAC
OUTPUT 5
115/200VAC/60Hz
1: 208V 3 PH 8A
2: 120V 1 PH 3A
3: 120V 1 PH 3A
375VDC
OUTPUT 6
375VDC
5A
RESISTIVE LOAD
• Six outputs for specific ship loads
440VAC
•Another useful feature of the PCM1A is that it has
energy storage capability for ~1sec, enabling the
support of uninterruptable (UI) loads.
50A
Determining Least Replacable Units
• It is necessary to determine the Least Replacable Units (LRU) to minimize cost
• Choice of LRU determines how sailors will do repairs on the fly
• IPNC contains AC to DC, DC to DC, and DC to AC converters, all of which have
duplicate components
DC to DC Converter Isolated
AC to DC / DC to AC Converter
Vin/
Vout
DM
CM
DM
Vout/
Vin
CM
DC to DC Converter Isolated
DM
Converter topologies and likely
LRU choices
Vout
CM
EMI Filtering
• Filters for the output of converters
must be designed to mitigate
conducted Electromagnetic
Interference (EMI.)
Ii+
1/
2
+
-
Idm
A
Vin
• Differential Mode (DM) and
Common Mode (CM) EMI must
be filtered
• Line Impedance Stabilization
Network (LISN) is modeled at output
of converter to measure EMI
LISN
Vi+
1/
2
+
-
ViIi-
Idm
Vi+
Vi-
Ig
N
Creating a Metamodel
• A metamodel is an equation or algorithm that will output the size and
weight of the cabinet given the materials and required power
specifications
• Size and weight is especially important in ship applications, because
space is limited and weight adds to fuel cost
• Size and weight can not be easily determined directly from the
physics of the cabinet
• Our IPNC metamodel is being created using an iterative process that
requires testing many different possible topologies of the converter
Construction and Testing with Wide Bandgap
Semiconductor material
• An input converter for the IPNC is being constructed and operation
with WBG semiconductor material is being tested in our lab
• Benefits of SiC MOSFET/diode switching devices are:
-Can operate at higher voltage,
-Higher temperature, and
-Higher switching frequency
• The end result is higher power density and efficiency
Summary
Given the Navy’s specifications for the IPNC, we are designing an
optimal power conversion cabinet by • Making the most cost effective choice of Least Replacable Units
• Designing filters to mitigate conducted EMI
• Testing WBG semiconductor devices to reduce overall size and weight
of the cabinet
• Creating a metamodel to quickly and easily determine feasibility of
future designs