Reactive Power Control of
Permanent-Magnet Synchronous Wind Generator with Matrix Converter
ABSTRACT:
In this paper, the reactive power control of a
variable speed permanent-magnet synchronous wind generator with a matrix converter
at the grid side is improved. A generalized modulation technique based on
singular value decomposition of the modulation matrix is used to model
different modulation techniques and investigate their corresponding input
reactive power capability. Based on this modulation technique, a new control
method is proposed for the matrix converter which uses active and reactive
parts of the generator current to increase the control capability of the grid-side
reactive current compared to conventional modulation methods. A new control
structure is also proposed which can control the matrix converter and generator
reactive current to improve the grid-side maximum achievable reactive power for
all wind speeds and power conditions. Simulation results prove the performance
of the proposed system for different generator output powers.
KEYWORDS:
1.
Matrix
converter
2.
Permanent-magnet synchronous generator (PMSG)
3.
Reactive power control
4.
Singular value decomposition (SVD) modulation
5.
Variable-speed wind generator
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Fig.1.
Simplified control block diagram of a PMSG.
CONCLUSION:
In
this paper, a new control strategy is proposed to increase the maximum
achievable grid-side reactive power of a matrix converter-fed PMS wind
generator. Different methods for controlling a matrix converter input reactive
power are investigated. It is shown that in some modulation methods, the
grid-side reactive current is made from the reactive part of the generator-side
current. In other modulation techniques, the grid-side reactive current is made
from the active part of the generator-side current. In the proposed method, which
is based on a generalized SVD modulation method, the grid-side reactive current
is made from both active and reactive parts of the generator-side current. In
existing strategies, a decrease in the generator speed and output active and
reactive power, will decrease the grid-side reactive power capability. A new
control structure is proposed which uses the free capacity of the generator
reactive power to increase the maximum achievable grid-side reactive power. Simulation
results for a case study show an increase in the grid side reactive power at
all wind speeds if the proposed method is employed.
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