Research On The Stability Of Marine Electric Power System

This paper treats low-voltage shipboard AC power system as the research object. Based on the characteristics of shipboard AC power system, this paper researches its stability combined with the mature theories of land power system.Firstly, three-phase models which include generator, transformer, transmission and distribution lines and load are researched according to the features of shipboard AC power system. Based on this, the power flow algorithm named U-I-MEPS which is fit for shipboard AC power system is established, combined with the similar characteristics between marine electric power system and land distribution system.Secondly, after making a research on the features of short-circuit current, this paper proposes a new method which is the combined programming for VB and MATLAB to research short-circuit current of shipboard AC power system based on China Classification Society's "Rules for the Steel Ships". Based on this method, the software used for short-circuit current of shipboard AC power system is developed and validated by the calculation example of Appendix A to Appendix One of title IV "Electrical Devices" in "Rules for the Steel Ships".The simulation model is built by MATLAB/SIMULINK to research the stability of shipboard AC power system. The simulation model includes models of the synchronous generator, excitation system, marine diesel engine and speed regulator system, and loads. Using these models, this paper researches the stability of shipboard AC power system, the simulation conditions include:load suddenly increased or decreased when one single generator is running, generators's running in parallel, load suddenly increased or decreased when two generators are running in parallel. The results show that the model which meets the "Rules for the Steel Ships" is correct, and the conclusion is credible.Finally, based on the research, some effective measures are proposed to improve transient stability and static stability of shipboard AC power system.