A Dual-loop Lyapunov-Function-Based Approach for Three-phase Stand-alone Inverter in d-q Frame

This paper proposed a dual-loop strategy to control three-phase stand-alone inverter in d-q synchronous rotating frame based on Lyapunov's second method, where the Lyapunov function was designed to signify the energy stored in filter inductor and filter capacitor. This approach successfully solved the inherent steady-state error problem in standard Lyapunov-function based method, with the information of inductive current and capacitive voltage. By analyzing root loci of characteristic equations, controller parameters were accordingly tuned with fully consideration of convergence time as well as damping ratio. Subsequently, simulation in SIMULINK verified the superiority of proposed approach over standard Lyapunov-function based both in steady state and transient scenario. Control hardware in the loop (HIL) system via OPAL-RT and dSPACE was further conducted to validate the efficiency and effectiveness of proposed approach.