Third-order sliding mode controller for Buck inverter

A novel third-order sliding mode control strategy for Buck inverter is proposed based on Lie derivative method in this paper. The geometry associated with the sliding mode control is presented for the analysis and design of the control scheme. The inverter is composed of two symmetrical current bi-directional Buck converters controlled by two independent sliding mode controllers. Base on the equivalent circuit of Buck inverter, the design procedures of the third-order sliding mode controller are given in detail. The sliding domain and sliding motion are described by phase trajectory vividly. To simplify the analysis, three-dimensional trajectory transforms into the two-dimensional one through the mapping transformation. Finally, experimental results are included to validate the proposed control strategy can ensure the system with improved tracking precision and well dynamic performances.