Modeling and dynamic feedback linearization of a 5-switch tri-state buck-boost bidirectional DC-DC converter

Abstract

Energy storage devices are frequently employed for dynamic voltage regulation in DC nano and microgrids. For that, the power electronic interface should allow fast and accurate control of the bidirectional power flow. This requires an appropriate set of power electronics topology and control strategy. This paper focuses on a novel 5-switch DC-DC converter capable of reversing the power flow direction without changing the current direction in the intermediate inductor. A tri-state buck-boost plus free-wheeling modulation scheme is discussed. One issue with conventional PI-type controllers designed for converter models linearized around a typical operating point is their performance deteriorates as the operating point changes. In such cases, advanced control methods based on non-linear control theory can be beneficial. This paper discusses an approach for the modelling and control by dynamic feedback linearization of a 5-switch bidirectional DC-DC converter. The performance is verified by means of simulation results.