Study On Maximum Power Point Tracking Of Hydrokinetic Energy Conversion Systems Using Sliding Mode Variable Structure

With the growing depletion of fossil fuels and the increasing pollution of fossil fuels,the search for clean,alternative green energy is imminent.Due to the large storage capacity,strong law,high energy density and a series of excellent characteristics,the research of Hydrokinetic Energy Conversion Systems attracted the attention of scholars from all over the world following the solar energy,wind energy after a large area of development.Hydrokinetic Energy Conversion Systems consists mainly of turbine and generator.However,If you don't control it,the system cannot get all the energy from the wave.And then,the system will be difficult to keep running at the best power point.This issue is the technical difficulties of the exploit of tidal current energy.This paper first introduces several commonly used maximum power point tracking(MPPT)control algorithms,and compares the advantages and disadvantages of these algorithms.Base on the horizontal axis tidal current energy system,the paper introduces the components of the system,including horizontal axis turbine,permanent magnet synchronous generator(PMSG),uncontrolled rectifier and Boost-Buck circuit.According to the existing wind power generation technology and tidal power generation technology,combined with the tip speed ratio algorithm,a maximum power point tracking control algorithm based on Sliding Mode Variable Structure(SMVS)is proposed.This paper carries out a simulation experiment based on this models with MATLAB.In this paper,the issue of MPPT have been converted to the problem of controlling tip speed ratio which equivalent of controlling the speed of system.At last,stable motor output,improve the impeller water capture coefficient,reduce the system shock and other control purposes come ture.The tidal power generation system which using the sliding mode variable structure be compared with the system without using MPPT or using the tip speed ratio algorithm.