Modified Sandia voltage shift anti‐islanding scheme for distributed power generator systems

Abstract

This study presents an active anti-islanding technique for distributed power generator systems. The proposed scheme is based on the Sandia voltage shift (SVS) technique, which is characterised by a small non-detection zone (NDZ) and by an acceptable solution to the trade-off between the output power quality and the effectiveness of islanding detection. The proposed technique has the advantage to improve the NDZ and to reduce the anti-islanding detection times. This is due to the exponential-product modification made in the positive feedback to inject current, thereby making the response faster than SVS. Additionally, a self-adaptive gain is considered to achieve a low total harmonic distortion at different power levels. Moreover, the proposed scheme has been validated with theoretical and numerical analysis and experimental results. Finally, the behaviour and performance of the proposed technique are compared with other recent techniques.