A Fractional Order Model Predictive Control Method for Electric-Hydrogen Hybrid Energy Storage System

A Fractional order model predictive control (FO-MPC) method for electric-hydrogen combined hybrid energy storage system is proposed in this paper. This method can help the converter of HESS to smooth the fluctuations of DG’s output better, improve the control accuracy of the converter output current and improve the stability of DC microgrid. Firstly, the structure of electric-hydrogen combined HESS is illustrated and DC microgrid system is described. Secondly, the concept of fractional calculus is introduced and the predictive model of DC Converter based on fractional order differential equation is established. According to the predictive model, the next current state of bidirectional converter of battery-ultracapacitor and converter of electrolyzer and fuel cell is predicted precisely. Finally, the fractional order model predictive control approach is experimentally verified in Buck/Boost circuit and significantly reduce the current ripple on the DC bus of the microgrid.