Research On Parallel Running For Diesel Synchronous Generator And The Ship Micro Source Inverter Of The Ship

As traditional non-renewable energy depletion and environmental pollution is increasing seriously,in order to maintain the sustainable development of the society and the economic,more and more attention has been paid on clean and renewable energy.In this context,new energy generation will be the future direction of the development of green ship.Ship-microgrid is an effective way to use new energy on a ship.If we can apply a reasonable-source inverter control strategy to the inverter via some energy saving devices so that it will perform like synchronous generators,then the parallel operation stability of the diesel synchronous generator with the ship-micro-source inverter can come true.The detail is specified as follows:Firstly,the theory of the synchronous generator and its ideal model was analysed,according to the characteristics of the ship power system.The equation under the abc coordinates and the Park transformation is described,and then the electromagnetic equations under the dqO coordinates is described,after that the equivalent circuit of d-axis,q-axis,the defined operator reactance and practical parameters is introduced saperately,then the fifth-order synchronous generator model derived.After the introduction of the diesel engine speed control system and excitation system of synchronous generator,the mathematical model is builted,based on that,the simulation analysis of single diesel synchronous generator running independently and in parallel operation is simulated.Subsequently,the concept of ship-source inverter virtual synchronous generator is introduced,the virtual synchronous generator algorithms and mathematical models is analysised and the virtual control system included the synchronous generator power frequency regulator and the voltage regulator is designed,after that the overall structure of the virtual synchronous generator is raised.On this basis,the simulation analysis of ship-micro-source inverter is described.Through virtual impedance links,the overall output impedance of the inverter was improved.To improve the dynamic performance of the parallel system,the improved droop methord has been proposed by adding differential equations in the conventional droop function,the dynamic response of the parallel system was improved.Finally,according to the theory and methods introduced above,simulation model based on the Matlab/Simulink simulation platform was built.And simulation of diesel synchronous generator running in parallel with the ship-micro-source inverter to build a ship-microgrid under different conditions has been taken,the simulation results demonstrate the effectiveness of the proposed model.