The Office of Naval Research is investigating and demonstrating technologies capable of reducing fuel consumption, improving power conversion efficiency, and increasing the installed power generation capacity on USS Arleigh Burke class ships. One effort, underway by General Electric, is examining the design, dynamic analysis and control of hybrid electric drive operating in electric propulsion and PDSS operating modes.
In propulsion mode using HED electric propulsion, the main gas turbines are secured. Gas turbine generators are electrically connected to a motor attached to each main reduction gear. The propulsion load is removed from the main gas turbines and placed onto the gas turbine generators. This mode allows the generators to operate optimally, lowering fuel consumption.
In generation mode using HED PDSS, the electric motors generate ship service power where the main gas turbines will be loaded to an optimal level reducing fuel consumption and securing a gas turbine generator to enable single generator operations. Additional ship service power can be generated by maintaining the gas turbine generator sets on line. The electrical distribution system is designed to handle the higher power output capacity.
The program calls for system integration, component and control technology development and a partial system demonstration. A demonstration will be conducted of the key electrical system features to investigate and validate the bidirectional drive technology and control logics for the electrical and propulsion subsystems.
By utilizing hybrid electric drive, the ship can optimally load the gas turbines to take advantage of their fuel consumption characteristics as well as reduce their operating time. Through the integration of mechanical and electrical systems the ship can operate at most speeds at a lower fuel consumption providing fuel savings and longer time on station.