| After the industrial revolution,human productivity had made considerable progress.However,the over-excavation of fossil energy that followed resulted in human beings facing new energy security problems.In order to alleviate the growing problem of energy security,humans have turned their attention to the sustainable development of clean energy such as solar energy.Bi-directional DC/DC converters play an important role in fully tapping the value of clean energy use.Therefore,it is particularly important to study the topology and control strategy of bidirectional DC/DC converters.The non-inverting Buck-Boost bidirectional converter has bi-directional multimode characteristics and has been applied to low-power electronic devices and medium-and low-power devices.Firstly,this paper analyzes its advantages and disadvantages in different modes.It has the Boost mode in both positive and negative directions.When the converter operates in Boost mode,it is equivalent to a Boost converter in circuit characteristics and is a non-minimum phase system.In order to offset the effect of the right half-plane zero,average current control was introduced.Secondly,using the average inductor current in combination with a constant voltage-constant current two-stage automatic switching charge-discharge strategy enables the converter to achieve energy bidirectional transmission.In the forward operation,the non-inverting Buck-Boost converter can convert a wide range of energy storage terminal voltage into a constant output voltage of the DC bus,greatly improving the power supply capacity of the energy storage unit.In the reverse operation,the control system implements a constant voltage-constant current two-stage automatic switching charging and discharging strategy to charge the energy storage unit according to the state of the energy storage unit.In addition,the converter shares a current regulator in both bidirectional modes,sharing a set of voltage and current compensator in unidirectional two modes for feasibility analysis and simulation verification.Finally,the peripheral control circuit of the non-inverting Buck-Boost bidirectional converter is designed and the program flow chart is developed based on the DSP controlchip.Build an experimental platform to verify the feasibility of the control strategy.Build an experimental platform and carry out preliminary experiments. |
