Optimal Tracking and Resonance Damping Design of Cascaded Modular Model Predictive Control for a Common-Mode Stabilized Grid-Tied $LCL$ Inverter

Abstract

A cascaded modular model predictive control (MMPC) method is designed for a modified nonisolated <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$LCL$</tex-math></inline-formula> grid-connected inverters to provide resonance damping, improved dynamic performance, and leakage current attenuation capabilities. The continuous control set model predictive control strategy is applied for the proposed method. The active damping function of the inner loop MMPC is analyzed in detail to illustrate the mechanism of improving the system dynamic performance. The cascaded MMPC method is compared with the conventional proportional-integral (PI) control methods with/without a notch filter to show the merits in resonance damping and dynamic response. The optimal control parameters design procedure is elucidated with the tuning mechanism of the MMPC weighing factor and PI gain. With the proposed optimal MMPC design method, the dynamic performance of rising time and overshoot are improved compared to the conventional PI control methods with/without the notch filter. The simulation and experimental results verified the proposed control design method.