1 DECLERCQ Jan BE Alpha 4 – Block 2 Barcelona 12-15 May 2003 TRANSFORMERS FOR WIND TURBINES NEED FOR NEW DESIGNS OR BUSINESS AS USUAL Dr. Jan Declercq
Dec 17, 2015
1DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
TRANSFORMERS FOR WIND TURBINES NEED FOR NEW DESIGNS OR
BUSINESS AS USUAL
Dr. Jan Declercq
2DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
Grid developments … todayEHV transmission Generation
100 MW >220 kV
Transmission
Sub-transmission 110 – 70 kV
Distribution 0.5-4 MW 30 kV
3DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
Grid developments … todayEHV transmission Embedded
Generation 100 MW >220 kV
Transmission
Sub-transmission 110 – 70 kV
Distribution 0.5-4 MW 30 kV
Overloading, power quality, economics, environment, maintenance, reliability
4DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
Types of distribution transformers
• Mineral oil filled transformers
• Cast resin transformers
• SLIM® technologysilicon oil and aramid insulation
5DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
Distribution TransformersMineral oil Cast Resin SLIM®
– Power in MVA 0.5..10..500 0.5..10 1..10– High voltage kV 10..36..500 10..33 10..36..– Low voltage V 400..6300.. 400..3000 400..3000– Impedance 4..10..25 4..8 5..10
Same operating range of voltages and powerWhat about other specifications?
6DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
Distribution Transformers
– No load losses and load losses– Dimensions– High load, ambient temperature and harmonics– Environmental issues– Fire behavior– Enclosures and cable boxes– Vibrations
7DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
Fit the door
8DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
No load losses, load losses, Dimensions
• No load losses– Ex. 2 kW * 8760 h/y * 0.05 EUR/kWh
• Load losses– Ex. 18 kW*Load factor2* 0.05 EUR/kWh*duration
so important how long and load level– Heat dissipation in turbine or substation
• Dimensions– Mass for nacelle installation– Flexibility to install, “fits the door”– Option to replace
9DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
High load, ambient temperature and harmonics
• Maximum allowable temperatures depend on insulation material– Mineral oil, cellulose 100°C– Cast Resin 155°C– Silicon oil 150°C, aramid insulation 200°C
• Maximum operating temperature depend on– Ambient temperature for transformer !!– Load and duration– Harmonic content
• Transformer specification– Ex. 60 K rise at full load and 30°C leads to 90°C
10DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
High load, ambient temperature and harmonics
Load P
Current I
Losses RI2
Temperature
11DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
High load, ambient temperature and harmonics
Load P
Current I
Losses RI2
Temperature
Lifetime
Tins 100 C
12DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
On-site measurements of thermal performance of a 2 MVA SLIM
transformer in a windturbine
13DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
Results and discussionPower in period 1vermogen
-500
0
500
1,000
1,500
2,000
0 200 400 600 800 1000 1200 1400 1600
Series1
14DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
Results and discussionTemperatures in period 1
0
10
20
30
40
50
60
70
80
90
100
10
/23
/20
01
10
/23
/20
01
10
/24
/20
01
10
/24
/20
01
10
/24
/20
01
10
/25
/20
01
10
/25
/20
01
10
/26
/20
01
10
/26
/20
01
10
/26
/20
01
10
/27
/20
01
10
/27
/20
01
10
/27
/20
01
10
/28
/20
01
10
/28
/20
01
10
/28
/20
01
10
/29
/20
01
10
/29
/20
01
10
/30
/20
01
10
/30
/20
01
10
/30
/20
01
10
/31
/20
01
10
/31
/20
01
10
/31
/20
01
11-0
1-0
1
11-0
1-0
1
11-0
2-0
1
11-0
2-0
1
11-0
2-0
1
11-0
3-0
1
11-0
3-0
1
11-0
3-0
1
11-0
4-0
1
11-0
4-0
1
11-0
4-0
1
Time
Te
mp
C
TR - Top oil
AIR - in
TR - Bot oil
HV - cab
HV - con
LV- bus
LV - cab
LV - bar
LV - bcap
LV - tcap
AIR - out
AIR - bot
AIR - top
AIR - amb
15DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
Fire behavior
• Depend on standards, laws, policies, habitsno strict guidelines for windturbines
• Transformers not treated active to fire– Source : do not start fire themselves
good reputation – Victim : depends on material
Technical specifications• Mineral oil class O (fire point 150 C)• Silicon oil class K3 (fire point 360 C )• Cast resin classes F0, F1 (similar numbers)
16DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
Vibrations• Transformers designed for transport
accelerations up to 3 g
• Wind turbine specificationsaccelerations <1 g, continuous and <100 Hz
Point 12 tank long side
0
0.2
0.4
0.6
0.8
1
0 25 50 75 100 125 150 175 200
Hz
XF
Rfu
nc
Ma
g
17DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
Increased failures• Much more voltage fluctuations due to step up • Sharp load fluctuations (1 to 100 % in 1 minute)• Fast Transient overvoltages between CB and
transformer (increased number of failures in Scotland and Denmark. Cigre 12-15 WG)
• More than 50 switching events per year• Increased average loading and harmonics• Vibrations• Moisture• Remote locations, reduced maintenance
18DECLERCQ Jan BE Alpha 4 – Block 2
Barcelona 12-15 May 2003
Increased failures
• Multiple transformers went on fire, even dry type
• On average 30 % more failure rate
• No possibility for replacement
• Long time for restart