Research On The Control Strategy Of Dual Active Bridge DC-DC Converter

The exploitation and utilization of renewable energy has developed rapidly in recent years。 Energy storage power stations,DC microgrids and electric vehicles have been widely used to make sure the effective utilization of renewable energy.The high efficiency conversion of electric energy between these devices is conducive to the development of the renewable energy industry,and the bidirectional flow of energy is a new direction for the management of energy.Therefore,the bidirectional Dual Active Bridge(DAB)DC-DC converter has received widely attention and research in recent years,and it is also important for the development of renewable energy.Firstly,topology characteristics and working modes of DAB converter were discussed.The control characteristics of three typical control methods in DAB converter were also analysed,such as Single Phase Shift(SPS),Dual Phase Shift(DPS),and Triple Phase Shift(TPS).And the active power and backflow power were calculated in those three controls.As high backflow power will cause the large power loss in DAB converter,this paper proposed a minimum backflow power control method based on TPS control,which has the highest degree of control freedom in above three control methods.This method can minimize the backflow power while make sure the active power can match the output power,which can improve the transmission efficiency of DAB converter.Secondly,in order to overcome the problem of slow dynamic-response speed of DAB converter in existing control methods,this paper proposed a Dynamic Matrix Predictive Control(DMC)method which is apply to DAB converter.There are error feedback correction module,model prediction module and rolling optimization module in DMC control,and the prediction error and control variation are optimized to get a better dynamic response.The simulation platform was built with Simulink to verify the better control performance of DMC control method in overshooting suppression and steady-state error reduction.Finally,a DAB experimental prototype was built to verify the effectiveness of the above control methods in this paper,and the details of the hardware and software design were also presented.For instance,the high-frequency transformer,drive circuit,sampling circuit,and the realization of soft start program and closed-loop control system which are based on TMS320F28335 DSP platform.Combined with the simulation tests in Simulink,the performance of the minimum backflow power control and DMC control method described above was verified,and the prototype tests also proved the effectiveness of those control methods.