Research On Control Method Of Marine Power System Stability

Ship electric power system is an islanded system, includes generation, distribution, transmission, and use of electricity, it provides electricity for the whole ship. At present, it is a development direction that the tonnage of ships is changing larger and the electrical capacity of ships have been increased a lot. Meanwhile, with the ships’ degree of automation becomes higher, more equipments need to be driven and controlled by electricity, people’s demand for supply quality and stability of power system is higher. Therefore, studies on the stability of ship electric power system is an important subject.In this paper, the principle and characteristics of ship electric power system are analyzed firstly, the mathematical model of synchronous generator with its excitation system and diesel engine with its speed regulating system are estabilished, on this basis, synchronous generator with its excitation system and diesel engine with its speed regulating system are modeling by simulation software, and the necessary loads are added to make ship electric power system completed. As the excitation control system is a nonlinear time-varying system, the fuzzy PID controller is designed to optimize it, considering the delay component of diesel engine with its speed regulating system, the fuzzy PID-Smith controller is designed to optimize it. The main working conditions of the system are simulated, and the stability of the system witout controller and the system with controller is compared and analyzed.The simulation results show that: the ship electric power system model can reflect the actual situation accurately when ship is sailing. When the working condition changes or the system has a fault, the controller can significantly reduce the overshoot and time to restore stability of generator terminal voltage and speed, and effectively improve the stability of ship electric power system.