Dr. Longya Xu
The Ohio State University
Dec., 2008
1. Introduction
� Major Wind Power System Configurations
� Challenges to Remain in Power Grid
� HVDC - Promising in Wind Power
2. What and Why DEBRM2. What and Why DEBRM
� System Configuration
� Features of Magnetic Structure
� DEBRM in Wind Power Generation
3. Conclusions
MW
New Installation
Cumulative Inst.
MW
2q Stator windings2p Stator windings GearsGears
Bi-Directional Inverters
Dual Stator Windings
No windings, No Slip Rings and Brushes, No Magnets on Rotor!!
Segmental Reluctance Rotor
[ ] [ ] [ ][ ]{ }
[ ] [ ] [ ] [ ] [ ]
[ ] [ ] [ ] [ ] [ ]r
r
dV i r L i
dt
d di r L i L i
dt dt
d di r L i L i
d dtω
θ
= +
= + +
= + +
α
θ
Sample 2-Phase
AC Machine
[ ]
0 0 sin cos
0 0 cos sin
sin cos 0 0
cos sin 0 0
sr r sr r
sr r sr r
r
sr r sr r
sr r sr r
K K
K KL
K K
K K
θ θθ θ
θθ θθ θ
− − − ∂ = +
∂ − − −
�
�
� � � �
�
�
rd dtθ α
β
θr
� All windings - magnetically coupled
� Lmutual - rotor position dependent
� Speed (motion induced) voltage exists
[ ] [ ]speed r
r
dV L i
dω
θ
=
� Electromagnetic torque
Electromechanical power
[ ] [ ] [ ]0 1
2
Tce
r r
LWT i i
θ θ∂∂
= =∂ ∂
EM m eP Tω=
2x 10
-4 2p=2 airgap flux
0 1 2 3 4 5 6 7-2
-1
0
1
Rotor angle
0 1 2 3 4 5 6 7-2
-1
0
1
2x 10
-4 2p=2 airgap flux
Rotor angle
0 1 2 3 4 5 6-2
-1.5
-1
-0.5
0
0.5
1
1.5
2x 10
-4 2p=2 airgap flux
0.02
0.04
0.062p=2 excited 2p=4 mutual inductance lAa-red lAb-blue lAc-green
Air gap Flux
Variation With
Rotor Rotating
Mutual
Inductance (Flux
0 50 100 150 200 250 300 350-0.06
-0.04
-0.02
0
0 50 100 150 200 250 300 350-0.06
-0.04
-0.02
0
0.02
0.04
0.06
Rotor angle
2p=2 excited 2p=6 mutual inductance lAa-red lAb-blue lAc-green
Inductance (Flux
Linkage)
Variation
Mutual
Inductance (Flux
Linkage)
Variation
p + q = prWith the above equation , the rotor speed
nr of the machine will be determined bynr of the machine will be determined by
60 ( )p q
r
f fn
p q
±=
+
Can Be Made Very Low Speed without Severe Size Penalty!!
Design Requirements:Design Requirements:Design Requirements:Design Requirements:Design Requirements:Design Requirements:Design Requirements:Design Requirements:
DirectDirectDirectDirectDirectDirectDirectDirect--------Driven:Driven:Driven:Driven:Driven:Driven:Driven:Driven: No gear boxNo gear boxNo gear boxNo gear boxNo gear boxNo gear boxNo gear boxNo gear box
Power Rating: Power Rating: Power Rating: Power Rating: Power Rating: Power Rating: Power Rating: Power Rating: 2,000,000w2,000,000w2,000,000w2,000,000w2,000,000w2,000,000w2,000,000w2,000,000wPower Rating: Power Rating: Power Rating: Power Rating: Power Rating: Power Rating: Power Rating: Power Rating: 2,000,000w2,000,000w2,000,000w2,000,000w2,000,000w2,000,000w2,000,000w2,000,000w
SpeedSpeedSpeedSpeedSpeedSpeedSpeedSpeed RangeRangeRangeRangeRangeRangeRangeRange: : : : : : : : 1010101010101010--------30rpm30rpm30rpm30rpm30rpm30rpm30rpm30rpm
Max. Torque: Max. Torque: Max. Torque: Max. Torque: Max. Torque: Max. Torque: Max. Torque: Max. Torque: 750,000 Nm750,000 Nm750,000 Nm750,000 Nm750,000 Nm750,000 Nm750,000 Nm750,000 Nm
Voltage:Voltage:Voltage:Voltage:Voltage:Voltage:Voltage:Voltage: 690 volts690 volts690 volts690 volts690 volts690 volts690 volts690 volts
Current: Current: Current: Current: Current: Current: Current: Current: 1,700 amps1,700 amps1,700 amps1,700 amps1,700 amps1,700 amps1,700 amps1,700 amps
Rotating PartStationary Part
Rotor Pole Number:2pr=240
Dual Stator Pole Numbers:2p=60 2q=180
Stator OD:3698.4mm Stator ID:3200mm
Rotor OD:3850mm Rotor ID:3700mmRotor OD:3850mm Rotor ID:3700mm
Effective L:1300mm
Estimated Weight of Copper:7.3T
Estimated Weight of iron :25T
Estimated Weight of Total :35T
-100.00
0.00
100.00
200.00
Y1 [Wb]
Ansoft Corporation Maxwell2DDesign1XY Plot 4
Curve Info
FluxLinkage(Winding2A)
Setup1 : Transient
FluxLinkage(Winding2B)
Setup1 : Transient
FluxLinkage(Winding2C)
Setup1 : Transient
0.00 50.00 100.00 150.00 200.00Time [ms]
-100.00
-50.00
0.00
50.00
100.00
Y1 [Wb]
Ansoft Corporation Maxwell2DDesign1XY Plot 5
Curve Info
FluxLinkage(Winding6A)
Setup1 : Transient
FluxLinkage(Winding6B)
Setup1 : Transient
FluxLinkage(Winding6C)
Setup1 : Transient
10.00 20.00 30.00 40.00 50.00Time [ms]
-200.00
转矩-功角曲线
200
400
600
800
1000
kNm)
Torque-Power Angle
-1000
-800
-600
-400
-200
0
200
0 100 200 300 400 500
功率角(°)
转矩(kNm
Power Angle
Torque
Machine
Performance
Doubly Fed IMG Direct-Driven PMG DEBRM Generator
Gear Box Required No No/Flexible
Size and Weight Small Very Big Big/Small
Inverter Capacity 30% 100% 100-30%
Brushes -Slip Rings Required No No
Permanent Magnets No Required No
Control Complexity Complex Less Complex Complex
Manufacturing Conventional Conventional Rotor-New
HVDC Compatibility No Yes Yes
Costs Less Heavy Less
• Wind power technologies are growing in fast-pace. Advanced wind
power generation system demands new technologies to enhance
system reliability and reduce costs;
• DEBRM has no windings, no brushes and slip rings on the rotor,with a rugged structure、and easy maintenance, showing high
potentials;
• It is possible to build doubly excited, directly driven wind power • It is possible to build doubly excited, directly driven wind power
generating system using DEBRM. Compared to PM direct-driven
systems, DEBRM direct-driven system needs no permanent magnets
and has a controllable field;
• Operated in the doubly excited mode, the capacity of the inverter in
DEBRM wind system is only a fraction of the total system capacity;
• DEBRM based wind power generation system is suitable for HVDC
power transmission for off-shore wind farm.