A new normalized Deadbeat control for grid connected distributed generation systems

This paper proposes a newly designed Real Time Digital Feedback Controller for a grid connected PV system. A multilevel Flying Capacitors Inverter (FCI) along with inductor and step-up transformer is used as an interface between the Distributed Generation system and grid. The proposed controller is Deadbeat type controlling simultaneously the grid current and capacitor voltages variables using a weighting factor to ensure a proper balancing among the controlled variables. Furthermore, the proposed approach is offering the possibility of duty cycles normalization when the reference is not achievable within the sampling period. The newly designed controller transfers the power to the grid even under voltage fluctuations resulting from grid faults. This Voltage Ride Through (VRT) capability is made possible without any noticeable current overshoot, while maintaining unity power factor and low harmonic distortion.