| Under the background of the development of renewable resources and the interconnection of various kinds of energy resources,DC microgrid,photovoltaic system,electric vehicle,energy storage systems have received tremendous demand and development.As the key equipment of power conversion device,bidirectional DC-DC converters have great research value.Due to the high economic value of the non-isolated bidirectional DC-DC converter,it has received widespread concern.Traditional non-isolated bidirectional DC-DC converters have large switching current and voltage stresses,and the voltage conversion ratio of traditional bidirectional DC-DC coverter is limited by the circuit parasitic parameters.Especially when under heavy load,it cannot achieve a high convertion ratio.Although the traditional interleaved type bidirectional DC-DC converter can reduce the total inductor current ripple,the voltage conversion ratio of the converter is still limited.When the parasitic parameters of each phase are unbalanced,the inductor currents of the converter will be unequal.Therefore,the traditional interleaved DC-DC converter usually cannot operate under open loop control,because the converter needs a control method to balance the inductor currents.In order to solve the problems above,a novel three-phase interleaved parallel high gain bidirectional DC-DC converter is proposed,which can achieve tree times the voltage conversion ratio of the traditional three-phase interleaved DC-DC converter.Compared with the traditional three-phase interleaved converter,the proposed converter only adds two capacitors,which has high economic value.The proposed converter not only has low switching voltage stresses and current stresses,but also has the current shaing and voltage balancing abilities.Therefore,the proposed converter can operate under open loop control.The current sharing and voltage balancing abilities make the converter closed loop design only need to sample the total inductor current and output voltage,which simplifies the design of the closed loop system.Switching strategy,working mode,steady state analysis,closed loop design,simulation and experimental verification are analyzed in more detail. |
