Research On DAB Converter Based On Phase Shift Control

With the rapid economic development,the demand for electricity is increasing,and the clean new energy represented by solar energy,wind energy and tidal energy gradually leaps into people’s vision.However,at the same time,how to solve the unreliability of new energy power generation has become a big problem.Dual Active Bridge(DAB)converter can realize bidirectional energy flow between DC voltage sources.It has been widely used in the field of new energy.In this paper,the basic principle of DAB converter and the current research status of control strategy are introduced firstly,and the circuit transmission characteristics of DAB converter under single phase shift,extended phase shift and triple phase shift control are analyzed respectively.Because the excessive current stress in the inductor will lead to the large loss of the device,and the power loss during the hard opening process of the switching device will lead to the decrease of efficiency,the inductor current stress is optimized under the control of triple phase shift with the highest degree of freedom.In order to calculate the shift comparison which can not only realize soft switching but also minimize current stress,modeling and calculation were carried out for different operating modes under triple phase shift control.The extreme value of conditions was obtained to compute the shift comparison which minimized current stress under different modes,and the operating range of different modes was summarized.The optimal control strategy of current stress under full power is obtained,which ensures the soft switching and minimizes the inductor current stress.Followed by direct power method to modeling of power output,the output voltage difference after PI controller compensation currents,and the sampling to get multiplied by the sum of the load current of the output voltage,output power,make the output power is equal to the transmission power,while ensuring the steady state characteristics at the same time,reduce system to adjust time,enhance its dynamic response speed.Finally,The experimental platform is built to test several control metheods including single phase shift,extended phase shift and triple phase shift modes,experimental results shows that triple phase shift direct power control method with current stress optimization has minimum current stress and fast dynamic response time...