Research On Nonlinear Characteristics And Coordinated Control Of MCFC-GT Hybrid System

The high temperature fuel cell-gas turbine hybrid system is an advanced efficiency and ecological power system, which rose at the end of last century and the beginning of this century. It has a wide application prospect in the field of electric power. However, the problem of the nonlinear characteristics and the coordinated control on hybrid system is a worldwide difficult problem for its compound and complex conversion process of energy. This paper presents a molten carbonate fuel cell -gas turbine (MCFC-GT) hybrid system as the study object to research the method of the coordinated control based on nonlinear characteristics of MCFC-GT hybrid system. The details are listed as below:(1) Model building of MCFC-GT hybrid systemBased on the mechanism modeling method, a lumped parameter model of MCFC-GT hybrid system is presented. The stable operating and the dynamic response performance of the hybrid system are discussed in this paper.(2) Research on characteristics of MCFC-GT hybrid system based on total energy conceptThis paper discusses the working performance of MCFC-GT hybrid system at diffirent work conditions. The results show that the hybrid system is high efficiency but the change range of work conditions is narrow. The work condition can be extended by a variable-speed gas turbine. However, this method of operation weakens the action of bottoming cycle. The advantage of hybrid system can't been good use fully.(3) Research on dynamic performance of MCFC-GT hybrid systemThis paper deeply studies the dynamic characteristics of MCFC. Based on the distribution of the temperature dynamic characteristics of MCFC, the dynamic performance of MCFC-GT hybrid system is presented. The results show the best working performance of hybrid system appears at design working condition. The hybrid system need longer time to stabilization for external disturbance. (4) ExperimentThis paper presents the performance experiments of MCFC, compressor and turbine to proof the simulation model of MCFC-GT hybrid system partially. The simulation result and the experimental result inosculate very well.(5) Research on coordinated control of MCFC-GT hybrid systemThe controlled performance of MCFC-GT hybrid system is very complicated. According to the nonlinear characteristic of hybrid system, three coordinated control strategies are presented and a fuzzy coordinated controller is built. The simulation of control performance of hybrid system results show the control method is great stable. The dynamic performance brings smaller overshoot and shorter adjusting time.