Performance enhancement of a stand-alone induction generator-based wind energy system using neural network controller

ABSTRACT

The limitation of self-excited induction generator (SEIG) when used in the stand-alone wind energy system (WES) is poor voltage regulation at variable speed. The indirect vector control (IVC) technique is employed for both the generator-side converter (GSC) and load-side converter (LSC) to regulate the variation of SEIG speed, DC link voltage, and electromagnetic torque independently. Further performance of the proposed IVC technique has been analyzed independently with neural network controller (NNC) and fuzzy logic controller (FLC) as its components. The FLC is replaced by an NNC to improve the performance of the proposed system. IVC of SEIG-based WES has been simulated in MATLAB/SIMULINK software, and the prototype model of the proposed WES is developed to experimentally validate the performance using dSPACE DS-1104 R&D controller board.

KEYWORDS:

• Wind energy system
• IVC
• neural network controller and fuzzy logic controller

Nomenclature

$\rho$	=	Air density
$R$	=	Radius of blade
$V_w$	=	Velocity of wind
${\omega }_t$	=	Prime mover speed
$\beta$	=	Pitch angle
$s$	=	Laplace operator
${\omega }_r$	=	Generator speed
$p$	=	Pole pairs
$T_e$	=	Electromagnetic torque
${\omega }_{sl}$	=	Slip speed
$v_{sd}$, $v_{sq}$	=	Stator voltages
$i_{sd}$, $i_{sq}$	=	Stator currents
$i_{rd}$, $i_{rq}$	=	Rotor currents
$i_{sm}$	=	Magnetizing stator current
$R_r$,$R_s$	=	Resistances of rotor and stator
$L_r$,$L_s$	=	Self-inductances of machine
$L_m$	=	Magnetizing inductance
${\lambda }_{sd},{\lambda }_{sq},{\lambda }_{rd},{\lambda }_{rq}$	=	Stator and rotor fluxes in direct-quadrature axis
$i_{ed}$, $i_{eq}$	=	Excitation capacitor currents for direct-quadrature axes component
$C_{ed}$, $C_{eq}$	=	Excitation capacitor in direct-quadrature axis
$\theta$	=	Transformation angle
$\sigma$	=	Leakage factor
${\tau }_r$	=	Rotor time constant

Acknowledgments

The current work is supported by the Ministry of Human Resource Development, Government of India through a Ph.D. scholarship grant.