DIRECT POWER CONTROL OF A DOUBLY FED INDUCTION GENERATOR BASED WIND ENERGY CONVERSION SYSTEMS INCLUDING A STORAGE UNIT

Abstract

To solve intermittent availability of popular renewable energy source based on wind energy, this paper deals with the design, analysis and simulation of a wind turbine associated with a storage unit to generate a constant active power through the grid for all wind conditions. A Doubly Fed Induction Generator (DFIG) allowing a large speed variation and so a large range of wind is employed. The incorporation of a battery or other energy storage device in the DC-link enables temporary storage of energy. Traditionally, control of DFIG is achieved by Flux Oriented Control (FOC), this technique decouples the rotor currents into active and reactive components; control of the active and reactive powers is achieved indirectly by controlling the input currents by using of classical Proportional-Integral (PI) controllers. However this controller depends highly on parameter variations of the DFIG. Direct Power Control (DPC), without inner current control loops, produces a fast and robust power response. Simulation results on a 1.5 MW DFIG system are provided to demonstrate the control strategy and the large interest of energy storage in such wind energy conversion systems (WECS)