Comprehensive design method of controller parameters for three-phase LCL-type grid-connected inverter based on D-partition

Abstract

The LCL-type inverter is a core component in grid-connected renewable energy systems, with its performance heavily influenced by the controller. Conventional design methods of controller parameters generally rely on approximation or trial and error, making it difficult to optimize parameters for multiple performance indices. This paper proposes a comprehensive design method of controller parameters for a three-phase LCL-type grid-connected inverter based on the D-partition method, obtaining a multi-objective parameter stability domain of controller parameters that simultaneously satisfies multiple performance indices, such as gain margin, phase margin, and current loop bandwidth. The stability domain can be visually presented, which can avoid repetitive adjustments. Additionally, the variation trend of the stability domain when there are deviations in the LCL filter parameters is analyzed. Finally, the accuracy and effectiveness of the proposed design method are validated through simulations and experiments, achieving precise parameter design for the controller of LCL grid-connected inverters even in the presence of deviations in filter parameters.