A Compound Control Strategy for Quasi-Z-Source T-Type Three-Level Inverter Based on Sliding Mode Control

In this paper, an adaptive weighted control strategy is introduced to enhance the stability of the inverter output voltage. This strategy integrates sliding mode control (SMC) with repetitive proportional control (RPC), leveraging the rapid attainment of steady state provided by SMC and the lower steadystate error characteristics of repetitive control (RC) under stable conditions. Initially, the state-space model of the inverter was established, and a sliding mode controller was devised. By incorporating variable exponential terms into the exponential convergence rate, the system swiftly approaches the sliding surface. Subsequently, a weighted controller (WC) that dynamically adjusts the weighting between the two control modes based on the instantaneous voltage error was utilized. This adjustment enhances system response speed while ensuring stability and robustness. Finally, comparative verification through simulation and experimental results demonstrates that the weighted composite control (WCC) strategy achieves faster transient response and superior robustness.