Grid synchronization control for an autonomous PV-wind-battery based microgrid

Abstract

This paper deals with the control of PWB (Photovoltaic-Wind-Battery) based MG (Micro-Grid) in standalone and grid-connected modes. The proposed MG works in standalone mode, and during peak load condition of the utility it is able to synchronize with the grid, and it operates in the grid-connected mode. In WECS (Wind Energy Conversion System), a SCIG (Squirrel Cage Induction Generator) is used to convert the wind energy into electrical energy. An INC (Incremental Conductance) based MPPT (Maximum Power Point Tracking) approach is used to extract maximum power from solar PV (Photovoltaic) array. The battery is connected at the DC-link of load/grid side VSC (Voltage Source Converter) for balancing the power flow in dynamic conditions of the system. In grid-connected mode, PL-EPLL (Pseudo-Linear-Enhanced Phase Locked Loop) based grid control algorithm is proposed to extract fundamental components of load currents. Along with grid synchronization and desynchronization, some ancillary services are also provided by the grid/load side VSC such as harmonics mitigation, load balancing and regulation of PCI (Point of Common Interconnection) voltages. The proposed MG is modeled, and its performance is simulated in MATLAB/ SIMULINK to verify the features of PWB based MG.