improvements in power electronic converters in wind energy system

1. A PAPER PRESENTATION
ON
IMPEDANCE SOURCE CONVERTER BASED
WIND ENERGY SYSTEMS
By
Althaf hussaisn Shaik(K L university)
Nadendla Srikanth(K L University)

2. THEME
• To improve the utilization of wind energy system using
efficient generator and suitable converter.
2221

3. OBJECTIVES
 The different generators used in wind energy
system.
 Why a PE converter needed in wind energy system.
 How the z source converter different from other
converters.
3
2

4. WIND ENERGY CONVERSION SYSTEM
 Fig: Block diagram
• Fixed speed wind turbines
• Partially Variable speed wind turbines
• Fully Variable speed wind turbines
Electrical
Generator
Wind
turbine
Power
electronic
interface
Gird
4
3

5. VARIABLE SPEED WIND ENERGY
CONVERSION SYSTEM
DFIG Transformer
Wind
gear external
box grid
partial-rating power converter
Fig: variable speed wind energy conversion system
G
DC
AC
AC
5
4

6. FULLY VARIABLE WIND ENERGY CONVERSION
SYSTEM
AC-DC
convert
er
DC-AC
convert
er
DC
AC
Grid
Gear
box
Syn generator
DC-Link
Fig: Fully-variable system 6
5

7. WHY DFIG ?
• DFIG provides more operating range compared to other
• It provides -40% to +30% speed range.
• The power flows in both rotor and stator
7
6

8. WHY A P.E CONVERTER IS NEEDED IN WIND
ENERGY CONVERSION ?
• The wind flows may not be fully controlled and can
cause variances in the frequency at which the power is
generated.
• Power electronic devices are utilized in these systems to
convert the generated ac voltages into HVDC.
• Through these devices, the power delivered by these
systems is cleaner and has a higher P.F .
8
7

9. COMPARISON OF WIND ENERGY CONVERSION
SYSTEMS
Sno:
WEC
Based on Generator
Grid
integration
1 Fixed speed
System
Induction
generator
Direct
2
Partially variable
System DFIG VSC
3 Fully-variable
system
Induction or
synchronous VSC or ZSC
9
8

10. WIND ENERGY CONVERSION SYSTEM
Fig: fully variable system
10
9

11. BOOST CONVERTER + INVERTER
Fig: WEC system with boost converter and inverter
11
10

12. Z-SOURCE INVERTER
Fig: WEC system with Z-source converter
12
11

13. SINGLE PHASE ZSC
v
z s a s
t
z s a s
Fig: single phase z-source converter
13
12

14. ACTIVE STATE
Fig: Active state 14
13

15. SHOOT THROUGH STATE
Fig: Shoot through state
15
14

16. SWITCHING SEQUENCE
S.no S1 S2 S3 S4 STATE
1 1 1 0 0 Zero
2 1 1 0 1 Shoot through
3 1 0 1 0 Active
4 1 1 1 0 Shoot through
5 0 0 1 1 Zero
6 0 1 1 1 Shoot through
7 0 1 1 0 Active
8 1 0 1 1 Shoot through 16
15

17. 4
Fig: MATLAB simulation
17
16

18. RESULTS
Fig: Active and shoot through states
18
17

19. ZSI SHOOT THROUGH STAGE
Fig: shoot through state
19
18

20. CONCLUSION:
• By using both DFIG and ZSI in wind energy systems we
can get more efficiency and control over the active and
reactive powers. The proposed system has high
performance, minimal count, increased efficiency and
reduced cost.
20
19

21. Any queries ???
21
20

22. Thank You
22
21