Research On The Stability Of Marine Power System

Compared to land power system, the capacity of the marine power system are becoming larger and larger, the automation level of the marine power system are becoming higher and higher. the marine power system is an independent power system with small size but very complicated structure, which has important effect in marine power system.The stability of marine power system is the fundamental for safe operation of the ship, the research of the transient stability of marine power system is always a very important subject.An excellent excitation control system can ensure the quality of the ship network voltage, which can improve the transient stability of the marine power system. The traditional excitation control method adopts PID controller, but the excitation system is a nonlinear and time-varying system, the traditional control method cannot change its controller parameters, the fuzzy PID controller can adjust its parameters with the control object. In this paper, we will research the excitation system with fuzzy PID controller and use MATLAB to simulate and test it.The frequency stability is another very important subject for the research of transient stability of the marine power system, and the ship network frequency depends on the speed of the prime motor, so the frequency stability can be obviously improved by improving the speed control system of the prime motor. Because the control object of the speed control system consists of pure time-delay part and its parameter is time-varying, in this paper we will research the speed control system of the diesel engine with fuzzy PID-Smith controller to improve the frequency stability of the marine power system and use MATLAB to simulate and test it.At last, the optimization design is given by the application of the fuzzy PID-Smith control theory in marine power system. Considering the influence of the coupling of the terminal voltage and speed, comprehensive controller is designed to improve the transient stability of the marine power system and we use MATLAB to simulate and test it. The simulation results show that, the fuzzy PID-Smith controller can improve the control accuracy of the terminal voltage and the speed of the prime motor, which has an excellent effect on the transient stability of the marine power system.