Pontifícia Universidade Católica do Rio Grande do Sul
Laboratório de Eletrônica de Potência – LEPUC
ACTIVE SHUNT FILTER FOR
HARMONIC MITIGATION IN WIND
TURBINES GENERATORS
FILTRO ATIVO PARALELO PARA MITIGAÇÃO DE CORRENTES HARMÔNICAS EM GERADORES DE
TURBINAS EÓLICAS
Reinaldo Tonkoski Jr., Fernando Soares dos Reis,
Jorge Villar Alé and Fabiano Daher Adegas;
Syed Islam and Kelvin Tan,
sexta-feira, 7 de abril de 2006
1/24
Table of Contents
 INTRODUCTION
 OBJECTIVE
 WIND ENERGY CONVERSION SYSTEM
 ACTIVE SHUNT FILTER
 POWER LOSSES
 SIMULATION RESULTS
 CONCLUSIONS
sexta-feira, 7 de abril de 2006
2/24
INTRODUCTION
- Wind power is the most rapidlygrowing
means
of
electricity
generation at the turn of the 21st
century. Global installed capacity
has raised 20% in 2004;
- Direct-driven wind turbine: multipole
permanent
magnet
synchronous generator (PMSG) and
three-phase bridge rectifier with a
bulky capacitor;
sexta-feira, 7 de abril de 2006
3/24
INTRODUCTION
- Non-linear characteristic: harmonic
current content flows into the
PMSG;
- Increase
PMSG
temperature;
sexta-feira, 7 de abril de 2006
losses
and
4/24
OBJECTIVE
- Analysis and simulation of an
active shunt filter (ASF) for
harmonic mitigation in wind
turbines generators.
sexta-feira, 7 de abril de 2006
5/24
WIND ENERGY CONVERSION SYSTEM
(WECS)
Dynamic Model: Variable-speed, direct driven
wind turbine.
sexta-feira, 7 de abril de 2006
6/24
PMSG WAVEFORMS - BRIDGE RECTIFIER
WITH BULKY CAPACITOR (NO ASF)
WECS full load condition – 12 m/s
(20 kW resistive load, Clink=5000uF, RL=6.5 Ω, VL=360 V)
PMSG output currents and line to line voltage div. by 4.
sexta-feira, 7 de abril de 2006
7/24
PMSG HARMONICS - BRIDGE RECTIFIER
WITH BULKY CAPACITOR (NO ASF)
WECS full load condition – wind speed 12 m/s
(20 kW resistive load, Clink=5000uF, RL=6.5 Ω, VL=360 V)
Phase Current
Line Voltage
sexta-feira, 7 de abril de 2006
8/24
3-PHASE ACTIVE SHUNT FILTER
Control filter current to actively shape the
source current is into the sinusoid.
iF  iPMSG  iC  i NL
sexta-feira, 7 de abril de 2006
9/24
ASF CONTROL CIRCUITS
REFERENCE CURRENTS
• Calculate harmonic currents;
• Regulate voltage on the capacitor CDC.
d-q Synchronous
Reference Frame
sexta-feira, 7 de abril de 2006
10/24
ASF CONTROL CIRCUITS
REFERENCE CURRENTS
i 
i  

1
 1  i a 

2 1
2
2  i 
3

3
 b 
3 0
2
2  ic 

i * Fa  i NLa  iaf
i * Fb  i NLb  ibf
d-q Synchronous
Reference Frame
 SRF 
1P
m ( s )
s 2
θSRF by mechanical
angular speed ωm
id   cos( SRF ) sin( SRF )  i 
i   
 
 q   sin( SRF ) cos( SRF ) i 
i * Fc  i NLc  icf
G( s) 



1
0

 i 
2  1

3
  


2  i
3 2
 


1
 3 


2
 2
sexta-feira, 7 de abril de 2006
i af

ibf
i cf

Low-Pass
k
Filter
sk
if  cos( SRF )  sin( SRF ) id 
i   
 
 f   sin( SRF ) cos( SRF )  iq 
11/24
ASF CONTROL CIRCUITS
CURRENT CONTROL BY PWM CARRIER STRATEGY
•Control current iF in order to inject the calculated
reference currents.
sexta-feira, 7 de abril de 2006
12/24
ASF PASSIVE POWER COMPONENTES DESIGN
cutoff 
t
C DC 
max  i F (t )dt
0
v DC max
Maximum accepted
voltage ripple ΔvDCmax
1
LF C
LC filter cutoff
frequency
LF 
VDC  Vn
di (t )
max NLn
dt
Maximum slope of
load current iNL
LF, CDC and C can be adjusted based on simulation results.
sexta-feira, 7 de abril de 2006
13/24
POWER LOSSES CALCULATION
Power
Losses
PMSG
Losses
Bridge Rectifier
Copper
Diode
PCU  3RA
PBR  6 VD I D _ AVG  rD I D _ RMS 

I
i 1
Ai
Core
Passive
Ppc  I pcRMS ESR
IGBT
2
 Vi  1
Ph
   
Ph1 i 1  V1  i

ASF
Losses
PIGBT  VCE SAT I IGBT _ AVG
2

 Vi  1
Ph
   
Ph1 i 1  V1  i
sexta-feira, 7 de abril de 2006
14/24
SIMULATION PARAMETERS
WECS Dynamic Model Implemented on Software PSIM®
20 kW
Parameter
Description
Value
LF
Inductor Filter
1.5mH
C
Capacitor Filter
3.9mF
fPWM
PWM Carrier Frequency
CDC
ASF DC Capacitor
vDC
ASF DC Voltage
Clink
Rectifier Bridge Link Capacitor
Rload
Resistance Load
6.5 Ω
D
Turbine Rotor Diameter
10 m
J
Turbine Inertia
B
Friction Coefficient
Ld
PMSG d-axis Inductance
5.24 mH
Lq
PMSG q-axis Inductance
5.24 mH
RA
PMSG Stator Resistance
0.432 Ω
sexta-feira, 7 de abril de 2006
20 kHz
10000 mF
500 V
5000 mF
1500 kg.m2
20 N s/rad
15/24
SIMULATION RESULTS
WECS full load condition – 12 m/s wind speed
(20 kW resistive load, Clink=5000uF, RL=6.5 Ω, VL=360 V)
sexta-feira, 7 de abril de 2006
16/24
SIMULATION RESULTS
WECS full load condition – 12 m/s wind speed
(20 kW resistive load, Clink=5000uF, RL=6.5 Ω, VL=360 V)
sexta-feira, 7 de abril de 2006
17/24
SIMULATION RESULTS
WECS full load condition – 12 m/s wind speed
(20 kW resistive load, Clink=5000uF, RL=6.5 Ω, VL=360 V)
1,2
THD=2.60 %
1,0
0,8
Phase Current
% 0,6
0,4
0,2
0,0
2
7
12
17
22
27
32
37
42
47
52
57
Order
sexta-feira, 7 de abril de 2006
18/24
SIMULATION RESULTS
WECS full load condition – 12 m/s wind speed
(20 kW resistive load, Clink=5000uF, RL=6.5 Ω, VL=360 V)
14
13
12
11
10
9
8
% 7
6
5
4
3
2
1
0
THD=20.77 %
Line Voltage
2
7
12
17
22
27
32
37
42
47
52
57
Order
sexta-feira, 7 de abril de 2006
19/24
SIMULATION RESULTS
WECS full load condition – 12 m/s wind speed
(20 kW resistive load, Clink=5000uF, RL=6.5 Ω, VL=360 V)
PMSG Losses
Total
(W)
η
(%)
Copper Losses
(W)
Core Losses
(W)
Friction & Windage
(W)
BR
2318.93
180.82
120
2619.75 88.42
ASF
2790.24
150.73
120
3060.97 86.73
Topology
ASF Losses
IGBT Losses
(W)
199.44
sexta-feira, 7 de abril de 2006
LF Losses
(W)
C Losses
(W)
CDC Losses
(W)
Total
(W)
284.66
0.2166
116.00
600.33
20/24
SIMULATION RESULTS
WECS full load condition – 12 m/s wind speed
(20 kW resistive load, Clink=5000uF, RL=6.5 Ω, VL=360 V)
Electrical Losses
Topology
PMSG Total
(W)
ASF Total
(W)
Rectifier Total
(W)
Efficiency
(%)
BR
2619.75
0
95.16
88.05
ASF
3199.92
603.03
211.82
84.74
WECS Efficiency
Topology
Aerodynamical
(%)
Electrical
(%)
Overall
(%)
BR
43.26
88.05
38.09
ASF
43.88
84.74
37.18
sexta-feira, 7 de abril de 2006
21/24
CONCLUSIONS
 The use of active shunt filter in wind
energy generation systems for harmonic
mitigation
was
analyzed
and
computationally simulated.
The ASF is able to mitigate harmonic
content of current that flows on the
permanent
magnet
synchronous
generator.
A capacitor bank filter was used to
suppress
high-switching
frequency
voltage component generated by the
ASF on generator terminals.
sexta-feira, 7 de abril de 2006
22/24
CONCLUSIONS
 The d-q SRF synchronization using the
angular rotor speed had worked, and its
physical implementation using sensors
must be investigated.
The ASF could diminish voltage core
losses. Although, PMSG efficiency is
lower because copper losses are higher
when using ASF.
Overall wind energy conversion system
efficiency is lower as well, so the use of
ASF could be justified if only the PMSG
generator could have a larger life cycle.
sexta-feira, 7 de abril de 2006
23/24
Obrigado!
sexta-feira, 7 de abril de 2006
24/24