Research On Interleaved Parallel Technology And Sliding Mode Variable Structure Control Algorithm For Fuel Cell Hybrid Energy System

As the serious environment pollution and the shortage of oil energy,a new renewable green energy is necessary to replace oil and mitigate environmental pollution.Proton exchange membrane fuel cell(PEMFC)is a pollution-free renewable green energy,with low operating temperature,low operating pressure,low emissions and high energy conversion.But slow dynamic response of the fuel cell is its critical shortcoming.The new hybrid system combinate the advantages of fuel cells and the high power density of supercapacitor,there are wide application prospect.The system requires auxiliary energy to make up for this shortcoming,which can give full play to the advantages of fuel cells.For the hybrid system,as its core component,the DC converter plays a vital role and it can even be said that its performance largely determines the overall hybrid system performance.In this paper,fuel cell hybrid energy system research object,divided into three research parts.1)Based on the fuel cell and supercapacitor hybrid energy system the simulation platform was setup,the Simulink simulation model of fuel cell,supercapacitor,Buck and bidirectional Buck-Boost converter based on three-phase interleaved parallel technology is established.2)In this paper,an interleaved parallel technique is used to design a three-phase interleaved Buck-Boost bidirectional DC/DC converter.The overall structure of the system is given,and the basic working principle of Buck-Boost bi-directional DC/DC is analyzed.It is proved by theory and the simulation that the interleaved parallel technique is beneficial to reduce the output voltage and current ripple of the DC/DC converter,and it is helpful to improve the response speed of the system.3)The variable structure sliding mode control method is applied to the energy management controller,which can improve the system robustness.A Boost sliding mode controller is designed to eliminate the buffeting,which can speed up the system response speed,and reduce the ripple.Through the analysis of the Buck converter,the sliding mode controller of the buck converter is obtained.Simulation results show that the use of sliding mode controller can make the system output faster to follow its reference value,maintaining the stability of the bus voltage.Simultaneously the ripple is reduced and the system response quickly.