Control of Three-phase Active Rectifier for Wind Turbine Applications

1
Control of Three-phase Active Rectifier for Wind
Turbine Applications
2
Contents

• Introduction
• System modeling and analysis
• LCL filter design
• Control design
• Simulation and implementation
• Conclusion

3
Introduction

• Types of Wind Turbines
• Horizontal axis
• Vertical axis
• Operation modes of WTG
• Constant Speed Constant Frequency
• Variable Speed Constant Frequency

4
Problem definition
Design and implementation of the control scheme
for the DC/AC converter in WTG in

• Grid connection
• Stand-alone

5
Hardware configuration
6
System overview
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Three-phase Active rectifier
RL-filter
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RL filter in rotating frame
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Grid mode controller design
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Active Rectifier control structure
Grid connected
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Model of the LCL filter
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LCL filter design
Qclt5 ZTlt10Zb ?reslt0.5?sw
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Current attenuation
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Current controller design
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Root locus
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DC-link controller design
CDCgtgt(Tei?0), optimal symmetry criterion
kDC0.7, Tet4.8ms
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Root locus
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Standalone control structure
Stand-alone
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Main voltage controller design
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Root locus
nominal load
1 load
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DC-link voltage limiter
Tet2.1ms, ?00.2ms
CDCgtgt(Tei?0), optimal symmetry criterion
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Root-locus
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DC-link choper operation
RDC

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Phase angle detection
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Simulation in grid mode
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Steady state simulation
Grid mode
Generating mode
Ideal phase voltage
2 5th 1 7th harmonics
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Simulation in stand-alone mode
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Steady state simulation
Stand-alone mode
phase voltages and current at nominal power using
resistive load
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Transient simulation
Stand-alone mode
System startup
Half of nominal load to nominal load
30
Implementation
dSPACE 1103 MPPC 604e at 633Mhz TMS320F240
16xADC-16 4?s 10V 4xADC-12 800 ns ? 10V
8xDAC-14 bit -6 µs ?10 7x IE interface
32xI/0 TDE software
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Combined control
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ControlDesk
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Steady state operation
Grid mode
Rectifying mode
Generating mode
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Transient operation
Grid mode
Nominal load system startup
Disturbance rejection
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Steady state operation
Stand-alone mode
Resistive load
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Steady state operation
Stand-alone mode
3-phase diode bridge
37
Transient operation
Stand-alone mode
Full load applied on the half of produced power
38
Transient operation
Stand-alone mode
Short-circuit startup
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Automatic mode switch
Idle mode
I-SA
I-GM
GM-I
SA-I
Stand-alone mode
Grid mode
GM-SA
I-GMUG and /PLLe and /TRIP and START I-SA/UG
and /TRIP and START GM-I TRIP or STOP SA-I TRIP
or STOP or PLLe GM-SA PLLe
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Grid mode to Stand-alone mode transition
nominal load
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Stand-alone mode to Grid mode transition
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Conclusion

• Vector based control of DC/AC converter with near
  unity power factor was succesfully designed,
  simulated, implemented and verified.
• LCL filter was designed, implemented and tested
• Two different control strategies were implemented
  according to the operating modes
• A common controller design procedure is used to
  tune controller parameters
• PLL is designed to detect phase angle
• Two different control strategies are implemented
  and tested in dSPACE.
• Automatic mode detection and switching betwen
  modes can be implemented