Harmonic Profile Injection-Based Hybrid Active Islanding Detection Technique for PV-VSC-Based Microgrid System

In this paper, a new investigation on islanding detection method is presented for PV-based VSC system. The proposed PV-VSC is represented as one of the distributed energy resource (DER) for a microgrid environment. A new multivariable dynamic model is presented in terms of two stage conversion with a dc-dc converter for the proposed PV-VSC system. The proposed VSC system is controlled primarily by a positive sequence P-Q loop, at the PCC. A new backstepping fast sliding mode control (BFSMC) is proposed for primary PWM control of VSC system. During sudden grid disconnection an islanding protection loop based on rate of change in voltage harmonic profile injection is proposed. A binary tree (BT) threshold filter is designed for the proposed hybrid islanding protection loop, to avoid false detection during other grid operational issues. UL 1741 (section 46) standard is followed for the PV-VSC system to consider the worst-case scenario. Performance of the proposed hybrid islanding protection scheme is investigated for IEEE 9 bus system with multiple DERs, implemented in MATLAB/Simulink environment. The effectiveness of the proposed scheme is determined by result analysis, where no significant effect on power quality is recorded during nominal grid operation.