Research on fractional order PID controller applied to PEMFC pre-stage power conversion

The soft electrical properties are limiting Proton Exchange Membrane Fuel Cell (PEMFC) to be directly applied. To overcome such shortcoming, the high efficiency structure Four Switch Buck-Boost (FSBB) converter, which combines with Fractional Order PID (FOPID) controller, is used as pre-stage power converter of PEMFC to achieve regulated output. Also, Particle Swarm Optimization (PSO) based on the optimization of similar ITAE performance index is used to optimize FOPID controller parameters. And in order to reduce the probability of PSO falling into local optimum prematurely, the fitness variance is introduced to adjust the inertia weight change rule. Finally, compared with the traditional PID controller, the FOPID controller can make FSBB converter have a more excellent dynamic and steady performance, especially in the system parameters even the structural change, which shows a stronger robustness.