Fuzzy Control Strategy Feasibility Analysis For ITER PF Power Supply Ac/Dc Converter

The International Thermonuclear Experimental Reactor(ITER)is one of the ultimate attractive solutions to sort the energy crisis by generating large amount of carbon-free energy.The Poloidal Field(PF)converter,as a significant part of the ITER device,plays essential role in the plasma shape and position control in vertical and horizontal direction.The AC/DC PF converter power supply is very complex,highly nonlinear and time varying in nature.Its physical model has a growing interest to realize the performance of the control system.However qualitative analysis of the control strategy needs a robust solution and still open to explore.The novel approach based on fuzzy control strategy has an excessive ability to addresses the issues of the complex nonlinear and inherent uncertainties.In order to develop the control strategy within the ITER PF converter and existing conventional controller is modified.In this thesis,the feasibility analysis and design of three kinds of fuzzy controllers have been deliberated for ITER PF converter system.The high reliability of their fuzzy controllers can provide a higher control performance than the conventional controller for the PF converter system.Firstly,the mamdani fuzzy strategy was investigated to analyze the dynamic behavior and uncertainties by assessment with the conventional and PI controller.Human knowledge and experience based control strategy of the existing behaviors of the power converter analyze mamdani fuzzy controller.Three basic operational topologies as single,parallel and circulation are provided using mamdani fuzzy controller simplify and design optimizing the controllers.Secondly,the Takagi Sugeno(TS)fuzzy controller shows its ability,performance,stability,analysis,and design for nonlinear complex ITER PF system.The advantages of the TS fuzzy modeling highlighted their simplify structure,properties,solved by modern optimized technique,which does not need mathematical modeling.Thirdly,the novel type 2 controller fuzzy is the design membership functions(MFs)and rules.The uncertainties always happen to design the membership function in actual applications.The type 1 fuzzy controller has limitations and cannot handle the uncertainties.The ITER PF converter is complex system and it requires high degree of accuracy to satisfy requirements.Lastly,generally this work elaborates the performance of fuzzy controller instead of the conventional PI controller.It indicates that different fuzzy controller is more attractive robust approach handle dynamics and uncertainties compared with PI controller.