Optimal Design of Phase-Shift Algorithm for Anti-islanding Protections in Inverter-based DG Systems

Islanding of photovoltaic (PV) systems may cause a variety of problems and must be avoided. Phase shift techniques is a good solution because it has high effective and costless in implementation. Optimal design of Phase shift techniques to certify the required anti-islanding Standard and grid quality is a challenge problem. This paper analysed the frequency deviation of PV systems after grid is disconnected. The non-detection zones (NDZs) are mapped into a load parameter space and the ability of anti-islanding can be evaluated properly. Based on it the parameters in phase-shift algorithm can be chosen wisely and least distortion of PV output current is achieved.