Load sharing of Multiple DFIGs in islanded mode Microgrid

Abstract

Now a day’s wind power energy is playing a major role in power industry. Among the different form of variable speed
fixed frequency topologies DFIG is most popular form due to its efficiency and ability to allow wide range of speed variation at
reduced converter size. When wind power penetration is high, the available generation may be more than needed, especially for windpowered micro grids working autonomously. Because the maximum peak power tracking algorithm may result in a supply-demand
imbalance, an alternative algorithm is needed for load sharing. Here fully distributed control scheme is presented to coordinate the
operations of multiple doubly-fed induction generators (DFIGs) in a micro grid. According to the proposed control strategy, each bus
in a micro grid has an associated bus agent that may have two function modules. The global information discovery module discovers
the total available wind generation and total demand. The load sharing control module calculates the generation reference of a DFIG.
By controlling the utilization level of DFIGs to common value, the supply demand balance can be maintained. The generated control
references are tracked by coordinating converter controls and pitch angle control. Simulation results with a 5-DFIG micro grid
demonstrate the effectiveness of the proposed control scheme.