U.S.S. Makin Island: Simulation-Based Analysis and its Role in Electric-Plant Control System Design

The LHD 8 amphibious assault ship (Makin Island) is currently under construction at Northrop Grumman Ship Systems, in Pascagoula, MS. A hybrid propulsion plant, in which the ship has the capability to be propelled by electric propulsion motors or gas turbine engines, exists aboard LHD 8. The electric propulsion motors provide for totally-electric propulsion for the majority of Makin Island´s operation at low speeds. The Makin Island concept for electrical power generation, distribution, and electric propulsion represents the intent of the all-electric warship i.e., a highly automated electric-plant with minimal manning. This and other similar electric-plant system topologies offer alternate means of supplying power to loads by reconfiguring main distribution paths. Automated plant reconfiguration (load shedding) and power management is accomplished by a digital Machinery Control System (MCS) for various casualty or loading conditions. An Electric Plant Computer Model Simulation (EPCMS) is used to assess the impact of faults, plant stability, signal latencies, etc. with regards to the electric plant. Several system design configurations were analyzed during ship construction based on simulation results. This paper illustrates the role that dynamic simulation-based analyses can play in influencing electric plant designs as it applies to the parallel diesel generator load sharing algorithm and plant reconfiguration as well as an evaluation of the response of the existing simulated system and the relative improvement in response with the proposed upgrades.