The CVRC Based Grid-Forming Inverter State Feedback Optimal Control Design

As the key interface for distributed power generation grid connection, inverters have become increasingly prominent in traditional power distribution systems due to their voltage and frequency supportabilities, with the increasing penetration of the renewable energy sources. This paper focuses on the voltage control of inverters, and proposes a closed-loop system with a reduced-order state space model established through feeding the state variables to the reference voltage control input using a complex variable resonant controller (CVRC). The optimal state feedback law is designed based on the linear quadratic (LQ) optimal control method, which ensures the global stability of the system. Compared with conventional methods, this control method has the advantages of lower model order, smaller computational complexity, and simpler control calculation, and has good reference-tracking and disturbance-suppression performances.