Modelling and real-time simulation of an advanced marine full-electrical propulsion system
After being consolidated as the preferred propulsion system for cruise ships, integrated full electrical propulsion (LFEP) is now being considered as the natural choice for the future warship vessels. The United States and the United Kingdom are developing parallel projects in order to gain broad knowledge of this new propulsion technology. The Royal Navy's Type 45 Destroyer, due to enter into service in 2007, will set the course by development and acquisition of practical experience for the Future Surface Combatant Ship (FSC) and the Future Aircraft Carrier (CVF) programmes, both envisaging the use of integrated full-electrical propulsion. One main step towards this new technology is the computational simulation of each independent component and of the system as a whole, to de-risk and refine the design. The present project aims to develop a computational model of an advanced marine integrated full-electrical propulsion system such as the one being proposed for the Royal Navy's Type 45 Destroyer. The main focus is the development of new advanced electrical equipment models, which are the building blocks of the propulsion system, to be integrated with some existing models from various earlier investigations, to achieve an Integrated Full Electric Propulsion System Model. Two particular aspects of this work are: The construction of an algorithm for the 15-phase induction motor capable of processing the resulting currents at the machine more precisely than the traditional -algorithms, taking into account eventual unbalances and faults in the voltage supply The development of a Direct Torque and Flux Control algorithm for the 15-phase system, capable of maintaining the stability of the induction motor under severe transients, such as the crash-stop manoeuvring situation. The work concludes by assessing the performance of the proposed advanced marine propulsion system predicting its likely behaviour across a number of important scenarios.