ABSTRACT:
A novel control strategy for the
operation of a permanent magnet synchronous generator (PMSG) based stand alone
variable speed wind turbine is presented in this paper,. The direct drive PMSG is
connected to the load through a switch mode rectifier and a vector controlled
pulse width modulated (PWM) IGBT-inverter. The generator side switch mode
rectifier is controlled to achieve maximum power from the wind. The load side
PWM inverter is using a relatively complex vector control scheme to control the
amplitude and frequency of the inverter output voltage. As there is no grid in
a stand-alone system, the output voltage has to be controlled in terms of
amplitude and frequency. The stand alone control is featured with output
voltage and frequency controller capable of handling variable load. A damp resistor
controller is used to dissipate excess power during fault or over-generation.
The potential excess of power will be dissipated in the damp resistor with the
chopper control and the dc link voltage will be maintained. Extensive
simulations have been performed using Matlab/Simpower. Simulation results show
that the controllers can extract maximum power and regulate the voltage and
frequency under varying load condition. The controller performs very well
during dynamic and steady state condition.
KEYWORDS:
1.
Permanent magnet synchronous generator
2.
Maximum power extraction
3.
Switch-mode rectifier
4.
Stand alone variable speed wind turbine
5.
Voltage and frequency control
SOFTWARE: MATLAB/SIMULINK
CONCLUSION:
Control strategy for a stand alone
variable speed wind turbine with a PMSG is presented in this paper. A simple control
strategy for the generator side converter to extract maximum power is discussed
and implemented using Simpower dynamic system simulation software. The controller
is capable to maximize output of the variable speed wind turbine under
fluctuating wind. The load side PWM inverter is controlled using vector control
scheme to maintain the amplitude and frequency of the inverter out put voltage.
It is seen that the controller can maintain the load voltage and frequency
quite well at constant load and under varying load condition. The generating
system with the proposed control strategy is suitable for a small scale
standalone variable speed wind turbine installation for remote area power
supply. The simulation results demonstrate that the controller works very well
and shows very good dynamic and steady state performance
REFERENCES:
[1] Müller, S., Deicke, M., and De
Doncker, Rik W.: ‘Doubly fed induction genertaor system for wind turbines’,
IEEE Industry Applications Magazine, May/June, 2002, pp. 26-33.
[2] H. Polinder, F. F. A. van der Pijl,
G. J. de Vilder, P. J. Tavner, "Comparison of direct-drive and geared generator
concepts for wind turbines," IEEE Trans. On energy conversion, vol
. 21, no. 3, pp. 725-733, Sept. 2006.
[3] T. F. Chan, L. L. Lai,
"Permanenet-magnet machines for distributed generation: a review," in
proc. 2007 IEEE power engineering annual meeting, pp. 1-6.
[4] M. De Broe, S. Drouilhet, and V.
Gevorgian, “A peak power tracker for small wind turbines in battery charging applications,”
IEEE Trans. Energy Convers., vol. 14, no. 4, pp. 1630–1635, Dec. 1999.
[5] R. Datta and V. T. Ranganathan, “A
method of tracking the peak power points for a variable speed wind energy conversion
system,” IEEE Trans. Energy Convers., vol. 18, no 1, pp. 163–168, Mar.
1999.
