Switching Control of Sliding Mode and Passive Control for DC-Link Voltage of Isolated Shoot-Through Z-Source Inverter

摘要

To solved the direct current (DC) link voltage fluctuation in Isolated shoot-through Z-source inverter (IST-ZSI). A switching controller based on sliding mode control and passivity-based control (PBC) for DC-link voltage of IST-ZSI is proposed. The IST-ZSI is assumed working in continuous conduction mode. At first, a DC link voltage sliding mode controller is designed, which uses inductor current error and DC link voltage error as state variables. The sliding mode control law is deduced, and the range of sliding coefficients is determined, which satisfy the existence and stable conditions. Secondly, the passivity based controller is designed by the dynamic equation of the IST-ZSI. In addition, a right switching function is selected to achieve the dynamic switching between the sliding mode controller and the passivity-based controller. This control method overcomes the chattering problem of sliding mode controller in steady state and accelerate the response speed of the system. And the system has strong robustness. Finally, the simulation results verify the effectiveness of the DC link voltage sliding mode controller.