An uncertainty and disturbance estimator (UDE)-based robust power flow control for grid-tied DC/AC converters was reported in the literature to achieve accurate power delivery in the presence of various types of model uncertainties and external disturbances. In this paper, a bounded-voltage power flow control is proposed for grid-tied PV systems with the improvement of the existing UDE-based robust power flow control to provide AC voltage protection. With the bounded-voltage design, the output voltage of the DC/AC converter always stays within the given range, which avoids the integrator windup caused by the saturation unit with the inappropriate setting of reactive power reference. Both simulation and experimental results are provided to demonstrate the effectiveness the proposed strategies.
- AC voltage protection
- Bounded-voltage power flow control
- Grid-tied PV systems
- Integrator windup