Compulsory Islanding Transition Strategy Based on Fuzzy Logic Control for a Renewable Microgrid System

Advantages of microgrid integrated with a renewable energy system have been acknowledged in more and applications. Operating steadily during different modes is great significance, transferring must be transient, seamless, reliable to maintain the continuous electricity supply for loads, especially sensitive ones. As semicontrolled switch that unable shut instantly until zero point its current, thyristors should forced turned off by certain strategies minimise influence brought delay transferring. In this paper, compulsory turn-off strategy based on fuzzy logic control converter output voltage proposed. With strategy, an alterable reverse applied across conducting thyristor dynamically adjusting reference instruction closed-loop parameters depending changing rate rather than detecting polarity or current. Constraints from acquisition analog data error digital calculation will eliminated. Finally, simulation experimental results verify effectiveness proposed strategy.