04-06-2012, 02:24 PM
Design of a Robust Grid Interface System for
PMSG-Based Wind Turbine Generators
[attachment=24165]
Abstract
A robust and reliable grid power interface system
for wind turbines using a permanent-magnet synchronous generator
(PMSG) is proposed in this paper, where an integration
of a generator-side three-switch buck-type rectifier and a
grid-side Z-source inverter is employed as a bridge between the
generator and the grid.
INTRODUCTION
IN RECENT YEARS, wind energy has been regarded as
one of the significant renewable energy sources. Among
the existing wind power generation systems, their generators
can be categorized into four main types [1], [2]: 1) fixed-speed
squirrel-cage induction generator; 2) variable-speed wound rotor
induction generator that employs variable rotor resistance;
3) variable-speed doubly fed induction generator that employs
a frequency converter between the grid and its rotor windings;
and 4) variable-speed synchronous generator, which is either
a wound rotor synchronous generator or a permanent-magnet
synchronous generator (PMSG).
SYSTEM DESCRIPTION
Power Circuit Configuration
The configuration of the proposed system is shown in Fig. 2.
The wind power captured by the turbine is converted by the
PMSG and transferred to the grid via a three-phase three-switch
PWM buck-type rectifier in series with a Z-source inverter. The
detailed power circuit is shown in Fig. 3.
The main function of the generator-side PWM rectifier is to
regulate the power factor of the PMSG and to ensure sinusoidal
generator currents. A small LC input filter can be designed to
absorb the high frequency harmonics injected into the generator
by the rectifier switching action.
PMSG CONTROL SYSTEM
The control strategy for the generator-side converter (the
three-switch buck-type rectifier) is discussed based on the
equivalent circuit and phasor diagram of the PMSG shown in
Fig. 7. The machine terminal voltage serves as the input voltage
to the rectifier, termed as
V in, which is equal to the machine
back EMF
E
s minus the voltage drop in the machine impedance
(Rs + jXs).
CONCLUSION
In this paper, the design methodology, the simulation studies,
and the experimental validation of an integrated generatorside
buck-type rectifier and grid-side Z-source-inverter-based
PMSG wind generation system have been presented. The control
algorithms of the proposed topology have been developed
from Z-source and SVM principles.
PMSG-Based Wind Turbine Generators
[attachment=24165]
Abstract
A robust and reliable grid power interface system
for wind turbines using a permanent-magnet synchronous generator
(PMSG) is proposed in this paper, where an integration
of a generator-side three-switch buck-type rectifier and a
grid-side Z-source inverter is employed as a bridge between the
generator and the grid.
INTRODUCTION
IN RECENT YEARS, wind energy has been regarded as
one of the significant renewable energy sources. Among
the existing wind power generation systems, their generators
can be categorized into four main types [1], [2]: 1) fixed-speed
squirrel-cage induction generator; 2) variable-speed wound rotor
induction generator that employs variable rotor resistance;
3) variable-speed doubly fed induction generator that employs
a frequency converter between the grid and its rotor windings;
and 4) variable-speed synchronous generator, which is either
a wound rotor synchronous generator or a permanent-magnet
synchronous generator (PMSG).
SYSTEM DESCRIPTION
Power Circuit Configuration
The configuration of the proposed system is shown in Fig. 2.
The wind power captured by the turbine is converted by the
PMSG and transferred to the grid via a three-phase three-switch
PWM buck-type rectifier in series with a Z-source inverter. The
detailed power circuit is shown in Fig. 3.
The main function of the generator-side PWM rectifier is to
regulate the power factor of the PMSG and to ensure sinusoidal
generator currents. A small LC input filter can be designed to
absorb the high frequency harmonics injected into the generator
by the rectifier switching action.
PMSG CONTROL SYSTEM
The control strategy for the generator-side converter (the
three-switch buck-type rectifier) is discussed based on the
equivalent circuit and phasor diagram of the PMSG shown in
Fig. 7. The machine terminal voltage serves as the input voltage
to the rectifier, termed as
V in, which is equal to the machine
back EMF
E
s minus the voltage drop in the machine impedance
(Rs + jXs).
CONCLUSION
In this paper, the design methodology, the simulation studies,
and the experimental validation of an integrated generatorside
buck-type rectifier and grid-side Z-source-inverter-based
PMSG wind generation system have been presented. The control
algorithms of the proposed topology have been developed
from Z-source and SVM principles.