Coaxial Insulated Bus Pipe for High Energy Application
PROGRAM: PMS 407, Surface Ship Modernization; Robust Combat Power Control FNC
Develop a Medium Voltage Direct Current (MVDC) coaxial Insulated Bus Pipe (IBP)
conductor and associated components for integration onto U.S. Navy ships.
A MVDC coaxial IBP conductor with the associated connectors, bulkhead
penetrations, and shock excursion mounts for transmission of MVDC with voltages
in the range of 6 kV to 12 kV and ampacity from 2000 to 4000 amperes is required
to mitigate the challenges associated with cabling of available IBP
technologies. Existing cables are limited in ampacity to approximately 400-700
amps per conductor, which requires multiple paralleled cables and terminations.
Multiple paralleled copper cable conductors are difficult to install, heavy,
and require more of the ship’s internal volume to meet the needs of future
surface combatants. As such, higher conductor capacities are desired to
support higher power distribution without the need to install and maintain
multiple parallel cables and the associated terminations.
The Navy, as well as shipyards, are seeking an innovative MVDC IBP conductor to
improve power transmission and modular ship construction. Prior developments
resulted in single phase IBP design appropriate only for Medium Voltage
Alternating Current (MVAC) Navy distribution systems. Magnetic fields in MVDC
IBP must be limited so as not to disrupt other systems nor increase the ship’s
magnetic signature. To mitigate the magnetic fields of high power parallel MVDC
conductors, a coaxial IBP configuration with the associated connectors,
bulkhead penetrations, and shock excursion mounts are required.
This effort will require finding innovative solutions to enable bus pipe
technology to meet Naval traditional operating environment requirements These
requirements are in accordance to the Navy’s MIL-STD-1399. The proposed design
must be able to support a range of voltages from 6kVDC to 12kVDC and currents
from 2000 to 4000Amperes. 3000Amperes at 12kVDC provides 36MW, which will allow
a single coaxial MVDC IBP to support most loads. The design must also address
shock excursions of bulkhead penetrations and mounts.
Cost impacts will be evaluated for both the replacement of conventional cabling
with IBP and tradecraft manpower reductions due to the configuration changes to
preformed modular sections rather than pulling multiple long lengths of heavy
cable throughout the ship during construction.
In modular Navy ship construction, connection tubes and terminations must be
maintenance free to reduce the risk of loose-connections and associated
arc-faults. IBP must also meet US Naval application specification and standards
to include Shock Tests (MIL-S-901); Cables, Electric, Low Smoke Halogen-Free
(MIL-DTL-24643); Electromagnetic Interference Characteristics Requirements for
Equipment (MIL-STD-461); Electromagnetic Environmental Effects Requirements
(MIL-STD-464); 1399-MVDC interface specification; and IEEE 1580.1. A MVDC bus
pipe specification does not currently exist; however, the MVDC IBP system is
expected to comply with applicable Military standards and specifications, such
as shock, fire and Electromagnetic Interference (EMI). Electric and magnetic
fields must be managed and comply with Navy EMI requirements.
Develop a concept for MVDC coaxial IBP conductor and associated connectors,
bulkhead penetrations, and shock excursion mounts for transmission of 6 kVDC to
12 kVDC to support high power loads in Navy high power systems.
Demonstrate the feasibility of a MVDC coaxial Insulated Bus Pipe design concept
that meets the needs of the Navy as defined in the Description. Identify the
technical feasibility of the proposed concept, and demonstrate the concept
through modeling, analysis, and/or bench top experimentation where appropriate.
Capture the technical feasibility and estimated production costs for the
proposed concept in the Phase I Final Report. During a Phase I Option, if
exercised, awardees will provide for initial design specifications and
capabilities description to build a prototype solution in Phase II.
Design and build prototype IBP sections in straight and complex configurations.
Design and manufacture connectors necessary for testing. Provide viable design
of bulkhead penetrations and mounts allowing for shock excursions.
Develop a test plan to validate IBP to proposed Navy IBP standards. Test IBP
prototypes to U.S. naval application specifications and standards to include:
MIL-S-901, MIL-DTL-24643, MIL-STD-461, MIL-STD-464, 1399-MVDC interface
specification, and IEEE 1580.1.
DUAL USE APPLICATIONS: Support the Navy in transitioning the technology for
Navy use. The use of Insulated Bus Pipe in Navy construction will allow for
modular installation and enable optimized workflow of high-power distribution
systems installation in ship construction.
Power distribution systems in all commercial Medium Voltage high current
applications will benefit with reductions in size, weight and cost of cabling.
Current commercial applications are in cruise ship design and urban underground
power distribution in constrained environments.
J., Becker H., Butler J., Kuch H., Oeding D., Rumpf E., Steckel R.D. and
Volcker O. “Power Systems Engineering Committee, Underground High-Power
Transmission.” 7th IEEE/PES Transmission and Distribution Conference and
Exposition, Atlanta, GA, 1979. http://ieeexplore.ieee.org/iel4/5780/15427/00712717.pdf?arnumber=712717
J., Markle S. and Hilardes, W. “Naval Power and Energy Systems Technology
Development Roadmap.” 8 October 2015, NAVSEA Document Library. https://www.navsea.navy.mil/Portals/103/Documents/Naval_Power_and_Energy_Systems_Technology_Development_Roadmap.pdf
Insulated Bus Pipe; IBP; Solid Conductor; Coaxial DC Power; Modular Ship
Construction; Bulkhead Penetration; MVDC Distribution; Medium Voltage Direct