Robust 3IMPL Control Algorithm for Power Management of SyRG/PV/BES-Based Distributed Islanded Microgrid

In an islanded ac microgrid, a comprehensive algorithm of a three-phase, improved-magnitude, phaselocked-loop (3IMPL) control algorithm is developed in this paper to provide dc offset removal, steady-state error removal, and fast dynamic response. In addition, the control of the voltage-source converter (VSC) using the 3IMPL algorithm provides voltage and frequency control and elimination of harmonics of nonlinear loads. In the proposed microgrid, a solar photovoltaic (PV) array is connected to the dc link through a boost converter, and an incremental conductance technique is used for extraction of maximum power from a PV array. Due to intermittency of the PV array, a synchronous reluctance generator is used for pico-hydro generation because it is economical, ecologically sustainable, and extremely reliable and requires less maintenance. Moreover, a microgrid suffers from problems of variation in generation and continuous load fluctuations; therefore, for power balancing between the source and the load, a storage battery is connected across the dc link of the VSC through a bidirectional dc-dc converter. Test results on a prototype have verified the control strategy and are able to improve the power quality of the system at varying solar insolation and unbalance in the load.