Current Feed-forward Based Transfer Scheme for Grid-Tied Inverters Considering Islanding Detection
The growth of distributed generation (DG) has reshaped distribution networks on a global scale. DGs operating at the distribution level have the flexibility to function either as grid-following or grid-forming systems, depending on grid power availability. A robust islanding detection and control transfer mechanism is imperative to ensure a seamless transition between these modes during unintended islanding events. A unified control scheme (UCS) is proposed to facilitate dual-mode operation for 3-phase grid-tied DGs. Rapid and smooth transfer is achieved between operating modes based on a proposed grid-current feed-forward (GCFF). The proposed control structure elegantly combines state feedback-based active islanding detection with transfer of control logic (TCL), requiring minimal alterations to conventional power converter control architectures for DG. The GCFF is engineered to optimize both islanding detection and transfer speed while mitigating voltage transients during the process. It is specifically designed for DG systems equipped with swift active islanding detection capabilities. The integrated controller structure and GCFF enable the detection and control transfer within a single fundamental operational cycle. This capability holds true even in scenarios involving considerable mismatch between local loads and generation, as validated by comprehensive simulations and rigorous hardware testing in the laboratory.
History
Email Address of Submitting Author
sugotomaulik@iisc.ac.inSubmitting Author's Institution
Indian Institute of Science, BangaloreSubmitting Author's Country
- India