Design and Implementation of a Bidirectional DC-DC Power Converter for Energy-storage Systems of a DC Microgrid Using a Digital Controller

This paper presents the design and development of a four-switch synchronous buck-boost converter-based bidirectional DC-DC power converter controlled by using a microcontroller. The designed power converter joins with various components including an auxiliary power-supply circuit, a gate-driving circuit, a voltage-feedback circuit, a current-feedback circuit, etc. The adoption of the digital control scheme enhances the control flexibility and accuracy of the power converter by ensuring precise regulation and dynamic responses. Laboratory experimental results demonstrate that the developed power converter can effectively maintain stable operation under different load-change conditions, thereby verifying its operating stability and effectiveness. Finally, an experimental prototype of the bidirectional DC-DC power converter of rated 400 W is constructed, enabling bidirectional power transmission between its the high-voltage side of 72 V and the low-voltage side of 48 V.