Optimized Fractional Order Based Droop Control with Improving the Flexibility of a Microgrid

This work presents an improved four-levels hierarchical control strategy for flexible microgrid based on three-phase voltage source inverters (VSIs) connected in parallel. In the proposed strategy, zero-level is required to handle current and of VSIs. The primary-level that consists a decentralized controller modified universal droop by introducing fractional-order derivative. It used enhance power sharing quality during islanded mode desired generation grid-connected mode. secondary centralized control, frequency deviations caused primary-control are restored. Also, this level includes synchronization loop enables seamless transition between both operation modes. order improve flexibility microgrid, sequential logic approach tertiary level. exploited manage restoration loops at each transition, as well static switch (SS) which connect/disconnect to/from main grid. parameters optimized using self-learning particle swarm optimizer (SLPSO) algorithm. Simulations were performed highlight performances compared with well-known three-levels scheme.