18-07-2012, 11:02 AM
Modeling and Control of a Variable Speed Wind Energy Conversion
System Based on an Induction Machine
Modeling and Control.PDF (Size: 441.47 KB / Downloads: 65)
Abstract
This paper deals with the study of a
Wind Energy Conversion System (WECS) based
on a squirrel cage induction machine connected to
an infinite power grid through two double side
pulse width modulated converter systems. After
modeling of all components of the conversion
system, we develop a new approach to control the
electrical and mechanical variables. This
approach is based on the PI controller of the DC
link voltage, pitch control of the wind turbine and
a hysteresis controller for the grid side converter.
Then, a study of the performance of our system
under grid disturbances such as dip in the grid
voltage will be presented. This study justifies,
under specific conditions, bidirectional transfer of
power between the induction machine and the
grid, which confirms its application in the WECS.
Simulation results are carried out to show the
feasibility of the proposed approach.
Control of IMSC converter
The structure of the speed controller is shown in
Figure 4. Such a structure is to compare the actual
speed of the machine ( ) wr
to a reference speed( ) r w
The reference speed is reached so as to optimize (l ).
According to the characteristic (l ,b ) p C , for b = 0
the maximum value of p C is obtained when l = l opt .
Attachl to its optimal value with the measurement of
wind speed .
Control of the GSC converter
The aim of the GSC is to regulate the DC link
voltage and maintain the balance between the dc link
power and the injected powers to the grid. Several
approaches are used in literature. In this paper, we
use a hysteresis current controller to compare the
reference current ( ) k _ ref i and the actual current ( ) k i
This controller maintains the grid currents in a
hysteresis band.
Application and Simulation Results
To validate our proposed approaches, we performed
simulations of the WECS with nominal data and
parameters provided in Appendix. The simulations
are carried out with Matlab / Simulink.
Simulation of Wind Turbine and IMSC
converter
In Figure 7 we present the simulation results of the
IMSC converter with a scalar control, MPPT
algorithm control and the aerodynamic control «
Pitch Control ». We simulate the performance of the
proposed control strategy in case of a turbulent wind
speed. The profile is illustrated by Figure 6,
simulation results give the behavior of electrical and
mechanical variables.
Conclusion
In this paper, a control strategy of the WECS was
proposed. The control has permitted to regulate the
DC link voltage and the active and reactive power
injected to the grid.
The proposed control strategy was therefore
implemented for three cases that are first a wind
turbulent speed, second the bidirectionality of the
GSC converter and finally the behavior of the WECS
during a fault of the grid voltage dip. Simulation
results show the effectiveness of the proposed
techniques.
System Based on an Induction Machine
Modeling and Control.PDF (Size: 441.47 KB / Downloads: 65)
Abstract
This paper deals with the study of a
Wind Energy Conversion System (WECS) based
on a squirrel cage induction machine connected to
an infinite power grid through two double side
pulse width modulated converter systems. After
modeling of all components of the conversion
system, we develop a new approach to control the
electrical and mechanical variables. This
approach is based on the PI controller of the DC
link voltage, pitch control of the wind turbine and
a hysteresis controller for the grid side converter.
Then, a study of the performance of our system
under grid disturbances such as dip in the grid
voltage will be presented. This study justifies,
under specific conditions, bidirectional transfer of
power between the induction machine and the
grid, which confirms its application in the WECS.
Simulation results are carried out to show the
feasibility of the proposed approach.
Control of IMSC converter
The structure of the speed controller is shown in
Figure 4. Such a structure is to compare the actual
speed of the machine ( ) wr
to a reference speed( ) r w
The reference speed is reached so as to optimize (l ).
According to the characteristic (l ,b ) p C , for b = 0
the maximum value of p C is obtained when l = l opt .
Attachl to its optimal value with the measurement of
wind speed .
Control of the GSC converter
The aim of the GSC is to regulate the DC link
voltage and maintain the balance between the dc link
power and the injected powers to the grid. Several
approaches are used in literature. In this paper, we
use a hysteresis current controller to compare the
reference current ( ) k _ ref i and the actual current ( ) k i
This controller maintains the grid currents in a
hysteresis band.
Application and Simulation Results
To validate our proposed approaches, we performed
simulations of the WECS with nominal data and
parameters provided in Appendix. The simulations
are carried out with Matlab / Simulink.
Simulation of Wind Turbine and IMSC
converter
In Figure 7 we present the simulation results of the
IMSC converter with a scalar control, MPPT
algorithm control and the aerodynamic control «
Pitch Control ». We simulate the performance of the
proposed control strategy in case of a turbulent wind
speed. The profile is illustrated by Figure 6,
simulation results give the behavior of electrical and
mechanical variables.
Conclusion
In this paper, a control strategy of the WECS was
proposed. The control has permitted to regulate the
DC link voltage and the active and reactive power
injected to the grid.
The proposed control strategy was therefore
implemented for three cases that are first a wind
turbulent speed, second the bidirectionality of the
GSC converter and finally the behavior of the WECS
during a fault of the grid voltage dip. Simulation
results show the effectiveness of the proposed
techniques.