A Microgrid Based on Wind Driven DFIG, DG and Solar PV Array for Optimal Fuel Consumption

This paper presents a green energy solution to a microgrid for a location dependent on a diesel generator (DG) to meet its electricity requirement. The proposed microgrid is powered by two renewable energy sources such as wind energy conversion system (WECS) using doubly fed induction generator (DFIG) and solar photovoltaic (PV) system. The solar PV array is directly connected to common DC bus of back-back voltage source converters (VSCs), which are connected in the rotor side of DFIG. Moreover, a battery energy storage (BES) is connected at the same DC bus through a buck-boost DC-DC converter to provide path for excess stator power of DFIG. The extraction of maximum power both from wind and solar is achieved through rotor side converter (RSC) control and buck-boost DC-DC converter control, respectively. A modified perturb and observe (P&O) algorithm is presented to extract maximum power from the solar PV array. Moreover, the control of load side converter (LSC), is designed to optimize the fuel consumption of DG. A novel generalized concept is proposed to compute the reference DG power output for optimal fuel consumption. The microgrid is modelled and simulated using SimPowerSystems tool box of MATLAB, for various scenarios such as varying wind speeds, varying insolation, effect of load variation on bidirectional converter and unbalanced nonlinear load connected at point of common coupling (PCC). The DFIG stator currents and DG currents, are found balanced and sinusoidal. Finally, an experimental prototype is developed in the laboratory to validate the proposed scheme.