Research On Dual Phase Shift Control Strategy For Current Stress Optimization Of Dual Active Bridge Converter

Equipped with a certain capacity of energy storage is an effective way to solve the random fluctuation of renewable energy power generation.Bidirectional DC-DC converter is the key equipment in the energy storage system,and DAB converter is one of the Bidirectional DC-DC converter topologies suitable for the energy storage system.In this paper,the Dual hase Shift control strategy for optimizing the current stress of DAB converter is studied.Aiming at the shortage that the current stress of DAB converter is still large under light load under EPS control,the dps-rcs control strategy is proposed,Experimental verification is carried out.The main work of this paper is as follows:1.By analyzing the working principle,working process and basic working characteristics of DAB converter under single phase shift（SPS）control,the relationship model among current stress,return power and shift ratio of DAB converter under SPS control is established.Combined with the relationship between shift ratio and transmission power,the equations of current stress and reactive power with transmission power are further established.The closed-loop controller of DAB converter is designed,and the theoretical analysis is verified by simulation..2.The working principle,working process and basic working characteristics of DAB converter under the control of traditional Dual Phase Shift（DPS）and Eextended Phase Shift（EPS）are analyzed;The relationship model among current stress,return power and shift ratio of DAB converter controlled by DPS and EPS is established;The Lagrange equation with the objective of minimizing the peak value of inductance current is established;The optimal shift ratio combination of DPS and EPS control is obtained by solving the equation.Combined with the relationship between the optimal shift ratio and transmission power,the equations of current stress,reactive power and transmission power under DPS and EPS control are further established.The relationship between current stress and return power of converters under DPS,EPS and SPS control is compared and analyzed,and verified by simulation.3.Based on the above analysis,in order to further optimize the current stress of the converter,the Dual Phase Shift for Reduce Current Stress（DPS-RCS）control strategy is proposed by changing the phase shift mode,and the working principle,working process and basic working characteristics of DAB converter in DPS-RCS control are analyzed.The relationship model among current stress,return power and shift ratio of DAB converter under dps-rcs control is established.Combined with Lagrange equation,the optimal shift ratio combination of dps-rcs control is obtained,Combined with the relationship between optimal shift ratio and transmission power,the equations of current stress,reactive power and transmission power under the control of DPS and EPS are further established;The relationship between current stress and reactive power of converter under the control of DPS,EPS and DPS-RCS is compared and analyzed,and verified by simulation.4.The experimental prototype of 1k W DAB converter is designed,and the SPS,DPS,EPS and the proposed DPS-RCS control strategy are verified by experiments.Figure[100] table[1] reference[55]...