Transient load share management of a diesel electric hybrid powertrain for ship propulsion

In this paper, a transient load share methodology for a hybrid diesel electric marine propulsion system is presented. The aim of the system is the performance enhancement and reduction of gaseous emissions during low-load transient operation. The controlled variable is λ while the manipulated variable is the torque from the electric motor regulated by a frequency inverter. The model for the λ behaviour is based on experimental identification while λ values in feedback loop come from an actual and a virtual sensor, the later based on first principles modelling. A nominal model is used for the synthesis of a robust H∞ controller for the controlled variable regulation. Experimental results in a full scale hybrid diesel electric powertrain under realistic loading scenarios verified the successful hybridisation.