A Modified Lyapunov-based Control Strategy for a Single-Phase VSI with a Load Estimator

This paper proposed a modified Lyapunov-based control scheme for a single-phase stand-alone voltage source inverter (VSI) with a real-time load estimator in natural frame. Proposed load estimator was friendly for digital realization on a microprocessor without any differentiators and coordinate transformation. Load uncertainties and nonlinearities were dynamically compensated online via load estimator, instead of using one real-world current sensor. Routh-Hurwitz stability criterion was further used to prove small-signal stability of the system regulated by proposed approach. Controller parameter got tuned with fully consideration of damping ratio, convergence time as well as optimal output rated active power. Robustness analysis of proposed approach against parametric variations were conducted based on root-loci technique. Finally, experimental results validated the superiority of proposed control scheme via control hardware in the loop system (HIL).