Research On Integrated Simulation Of Large Cruise Electric Propulsion System

In recent years,the world cruise economy has been developing rapidly,however,the design and construction technology of cruise ships are mainly monopolized by Europe.Domestic research on the integrated electric propulsion system of cruise ships started late.As the heart of the cruise ship,the electric propulsion system has large capacity,high integration and stricter design requirements and standards in comparison with those of other ships.For the large and complex cruise electric propulsion system,it is necessary to fulfil the design,simulation and verification of the whole electric propulsion system with the idea of integration,considering the relationships between the various modules in the system.In this paper,the overall design of cruise electric propulsion system is studied.The ship engine-propeller matching in electric propulsion system is completed based on the energy balance principle,considering the different working characteristics of podded propeller and conventional propeller.Combining with relevant standards and design experience,the parameters calculation of matching design of diesel generator set,transformer,frequency converter and POD propeller subsystems in electric propulsion system is carried out,and the main design parameters of each electric equipment are determined.In order to verify the validity and applicability of the design results,this paper uses the idea of modular modeling and MATLAB/Simulink software to establish the overall electric propulsion system model including diesel engine,generator,transformer,frequency converter and its control system,propulsion motor and other modules.The relevant modules are established and validated by the experimental data of diesel generator set and frequency conversion control system.The simulation model is applied to the power system of Vista class large cruise ship,which is equipped with two high-power diesel generators,four transformers,four frequency converters and two podded thrusters.The propulsion performance of the cruise ship under steady and acceleration conditions is simulated and analyzed.The results show that the design results of the cruise propulsion system meet the requirements of stable operation of the cruise under various navigation conditions,and the overload operation of the propulsion motor and other equipment can be avoided by adopting the control strategy of limited torque acceleration.Finally,the most harmful three-phase short-circuit fault in the power system is studied.Short-circuit fault seriously endangers the safety and reliability of the system operation.It is necessary to design the protection device for the electric propulsion system.The design scheme of electric propulsion system proposed in this paper is generic and can implement parameter calculation and equipment selection of ships in the preliminary design stage.The simulation model of electric propulsion system established in this paper can effectively analyze the propulsion performance of ships under different navigation conditions,and play a guiding role for the design of electric propulsion system.