Wind energy conversion system based on dual stator induction generator controlled by nonlinear backstepping and pi controllers

Abstract

To capture wind energy and to produce electrical power, many conversion systems have been proposed. This work treats also the modeling and the control of dual stator induction generator DSIG integrated in wind energy conversion system. In order to increase the flow of the power to the grid and to ensure an optimum operating point, it is very important to act on the generator side controllers and the conversion system output variables. The Proportional integral PI controllers have been widely used to control alternative machines. In this case, the inverters, which fed the DSIG, are controlled simultaneously with a displaced angle of 30°. So, the synthesis PI gains still difficult. To solve this problem, a nonlinear backstepping control is proposed. For that, the suggested study presents the comparison of the performances of the two strategies. Different simulation tests are conducted to evaluate the efficiency and the validity of the proposed control strategies. We notice that in the steady state, the two controls allow the same performance (tracking). In transient mode, the backstepping command is better in terms of response time and overshoot.

Appendix: Parameters

Radius of the turbine:

R = 36 m

Gear box gain:

G = 90

Maximum power coefficient:

${\text{C}}_{\text{pmax}} = 0.44$

Optimal relative wind speed:

${\lambda }_{\text{opt}} = 7.05$

DSIG nominal power:

${\text{P}}_{\text{n}} = 1.5\;{\text{MW}}$

RMS voltage value:

U = 400 V

Frequency:

F = 50 Hz

Number of pole pairs:

${\text{p}}$ = 2

Stator resistance:

${\text{R}}_{{{\text{s}}1}}$ = ${\text{R}}_{{{\text{s}}2}}$ = 0.008 Ω

Stator inductance:

${\text{L}}_{{{\text{s}}1}}$ = ${\text{L}}_{{{\text{s}}2}}$ = 0.134 ${\text{mH}}$

Magnetizing inductance:

${\text{L}}_{\text{m}}$ = 0.0045 H

Rotor resistance:

${\text{R}}_{\text{r}}$ = 0.007 Ω

Rotor inductance:

${\text{L}}_{\text{r}}$ = 0.067 ${\text{mH}}$

Inertia:

J = 10 kg.m²

Viscous coefficient:

f = 2.5 Nm s/rd

Filter inductance:

${\text{L}}_{\text{f}} = 0.001 \;{\text{H}}$

Filter resistance:

${\text{R}}_{\text{f}} = 0.01 \;\varOmega$

Capacitance of the DC link voltage:

${\text{C}} = 0.072 \;{\text{F}}$