ABB FACTS Grid connection of Wind Farms

Transcription

1 Christian PAYERL ABB FACTS Grid connection of Wind Farms May 28, 2010 Slide 1

2 ABB Power of Wind May 28, 2010 Slide 2

3 ABB FACTS 300 engineers, highly skilled in the following disciplines: Development Marketing and Sales System studies and design Project management Quality control Testing and commissioning After sales May 28, 2010 Slide 3

4 FACTS Applications Flexible AC Transmission Systems May 28, 2010 Slide 4

5 FACTS Business structure and development Static Var Compensation - Utilities Series Compensation May 28, 2010 Slide 5 TCSC

6 FACTS Business structure and development SVC Light (STATCOM) SVC for Power Quality May 28, 2010 Slide 6

7 ABB SVC Installations 450 SVC installations (more than 310 for Power Quality) May 28, 2010 Slide 8

8 SVC - Static Var Compensator SC Serial Compensations Start of research First commercial installation Installed power Number of installations Mvar Mvar May 28, 2010 Slide 9

9 Generator Size Background May 28, 2010 Slide 10

10 System Studies - Grid Codes Background Many markets are currently installing or discussing installing large amounts of renewable generation Of all the renewable energy sources, wind is currently the most viable technology In the past wind farms were generally small (ten s of MWs) and connected mainly to distribution systems Today most of the wind farms planned are +100 MWs many are being connected to sub-transmission and transmission level Why shall large wind plants NOT match the same demands as other large traditional power plants? This prompts the need for systems analysis in the early stages of wind farm development to ensure proper integration into the transmission system and May 28, 2010 Slide 11

11 Grid Connection Background Offshore On-shore S/S Sub-Sea Export Cable transmission Collection grid Off-shore HV Substation AC network Onshore Reactive Power Compensation May 28, 2010 Slide 12

12 Critical aspect, Grid compliance - wind power General PICTURE JPG-FORMAT WEB OPTIMIZED RESOLUTION Reactive Power Balance Voltage Stability Frequency Control Fault Ride-Through Power flow May 28, 2010 Slide 13

13 Other Advantages with an SVC at the GCP General PICTURE Voltage & Transient Stability Power Oscillation Damping Load Balancing Power quality issues JPG-FORMAT WEB OPTIMIZED RESOLUTION Harmonic Mitigation Flicker Mitigation Voltage Transient Issues Resonance Issues May 28, 2010 Slide 14

14 System Design Studies Static analysis To define apparatus data and reactive power demand Load flow Short circuit Dynamic analysis To verify system design Harmonics Transient Stability Transient overvoltage Relay coordination Power quality analysis Harmonics Flicker May 28, 2010 Slide 15

15 European Wind Integration Study - EWIS General EWIS Report Page 22, page 24, page 47f May 28, 2010 Slide 16

16 Large Wind Farm Grid Connection Reactive Power Balance Source: National Grid May 28, 2010 Slide 17

17 Reactive Power Reactive Power Balance Reactive Power is a local phenomenon and cannot be transmitted effectively across large distances. The German power factor requirements for Prated above 100MW May 28, 2010 Slide 18

18 Reaktive power balance Reactive Power Balance MVar Leading Lagging MW IG DFIG FPC Grid Connection Point Lagging MVar Leading +.95pf MW -.95pf Pgen Qgen SVC P=Pgen-losses Q=Qgen+Qcabel-I 2 X Lagging MVar Leading MW Important impedance May 28, 2010 Slide 19

19 Reactive power balance Reactive Power Balance Generators giving local reactive power support are being retired, this disturbs reactive power balance. Load sensitivity regarding both fundamental frequency and harmonic voltages is increased. Customers are more sensitive to outages. Changed and often reversed power flow calls for studies and actions. May 28, 2010 Slide 20

20 Typical Requirement at the Connection Point (NGT) Rated Power output (MW) 100% P (MW) Reactive Power Balance 20% A C D B Q (MVAr) May 28, 2010 Slide 21 Point A is equivalent to: 0.95 leading Power Factor at Rated MW output Point B is equivalent to: 0.95 lagging Power Factor at Rated MW output Point C is equivalent to: -5% of Rated MW output Point D is equivalent to: +5% of Rated MW output

21 Possible FACTS Application Reactive Power Balance An SVC at the Connection Point can be used to control the entire, or part of, the reactive power. An SVC at the Connection Point makes it possible to minimize the losses within the wind farm and mitigates the risk for over voltages as well as reduce resonance problems. May 28, 2010 Slide 22

22 Voltage Stability, Introduction Voltage Stability Historically, wind farms have been excluded from the demand that generating devices should contribute to voltage stability. They cannot, however, expect to enjoy this favorable treatment forever. PICTURE Many regulatory authorities adapt the requirement that the wind parks should be able to vary there reactive power output depending on the grid voltage level. JPG-FORMAT WEB OPTIMIZED RESOLUTION May 28, 2010 Slide 23

23 Possible FACTS Applications Voltage Stability An centrally placed SVC stabilizes the grid. A solution with an SVC at PCC contribute to voltage stability independent of the active power production. May 28, 2010 Slide 24

24 Frequency control Frequency Control As well as for the voltage stability, new wind generation units are requested to contribute to frequency stability. PICTURE JPG-FORMAT WEB OPTIMIZED RESOLUTION May 28, 2010 Slide 25

25 Frequency control Frequency Control May 28, 2010 Slide 26

26 Possible FACTS Applications Frequency Control Active power needed. A FACTS device equipped with an energy storage is a possible solution. Clustering of smaller wind farms into larger production units makes it easier to apply solutions. May 28, 2010 Slide 27

27 Fault ride through Fault Ride-Through Minimum fault the system is required to survive. Symmetric and asymmetric faults. Depending on voltage level at Connection Point. Post fault behavior. Minimum active power as compared to before event. Reactive power and voltage control. May 28, 2010 Slide 28

28 Fault ride through Fault Ride-Through May 28, 2010 Slide 29

29 Advantages with an SVC at Connection Point Fault Ride-Through Fault Ride-Through is first and foremost a question for the Wind turbine generator manufacturers. An SVC can have a significant impact on the system after clearance of the fault. May 28, 2010 Slide 30

30 Wind Turbine Concepts General Fixed speed Induction generator (SCIG - fixed speed) Danish concept (2 Induction generator with variable slip (WRIG) Variable speed ASG with Inverter system (SCIG) Double feed induction generator with PWM inverter (WRIG) SG with Inverter system May 28, 2010 Slide 32

31 Induction generator direct connected to the grid Reactive power, voltage control Voltage stability, fault ride through May 28, 2010 Slide 33

32 Danish concept Reactive power, voltage control Voltage stability, fault ride through May 28, 2010 Slide 35

33 Induction generator with variable slip Reactive power, voltage control Voltage stability, fault ride through May 28, 2010 Slide 36

34 Wind turbine with inverter in main power circuit Reactive power, voltage control Voltage stability, fault ride through May 28, 2010 Slide 37

35 Synchronous generator wind SG G AC AC transformer Power Converter grid/stand alone Pitch control wind turbine Variable Speed Multi-Pole Synchronous Generator direct driven Rectifier + Inverter May 28, 2010 Slide 38

36 Double feed induction generator with PWM-inverter Reactive power, voltage control Voltage stability, fault ride through May 28, 2010 Slide 39

37 Background Other aspects Modelling aspects Aspect Model level Time scale Tool Wind turbines mechanical loads RMS 10-1 s 10 3 s Wind turbines power quality RMS 10-1 s 10 3 s Wind turbine control system RMS/EMT 10-3 s 10 2 s Wind turbine switchings EMT 10-3 s 10 1 s Grid faults EMT 10-6 s Power electronic control and design EMT 10-9 s s s HAWC DigSilent Matlab DigSilent/SABER PSCAD, EMTDC, SIMPOW, DigSilent SABER May 28, 2010 Slide 42

38 Network study Network study Harmonic Requirements Harmonic emission Background emission onshore grid WTG:s System resonance Harmonic Filter Design Type of filter, S-filter, C-filter, etc. 6,00 5,00 50,0 40, NODE PL33-W5B U POS. p.u / SQRT[3] kv NODE PL33-W6A U POS. p.u / SQRT[3] kv NODE PL33-W4A U POS. p.u / SQRT[3] kv NODE PL33-W3A U POS. p.u / SQRT[3] kv Resistor for increased damping Resistor => Heating => Losses => Forced Ventilation 4,00 30, ,00 2,00 20, ,00 10, ,00 0, FREQUENCY HZ May 28, 2010 Slide 43

39 Reasons Power Line (T or D) for bad power quality IG DFIG FPC Power quality NODE PL33-W5B U POS. p.u / SQRT[3] kv NODE PL33-W6A U POS. p.u / SQRT[3] kv NODE PL33-W4A U POS. p.u / SQRT[3] kv NODE PL33-W3A U POS. p.u / SQRT[3] kv 6,00 50, ,00 40, , , , , ,00 1,00 10, ,00 0, FREQUENCY HZ P, Q May 28, 2010 Slide 44

40 What is flicker? Flicker IEC , IEC UK, P28 China, GB/T Definition A group exposed to a flicker dose of Pst(99%) = 1.0, 50 % of them can observe the light flicker. May 28, 2010 Slide 45

41 Network Tower shadow In/out switching Flicker Background flicker May 28, 2010 Slide 46 Power electronic failure

42 Continouse operation Flicker Switching operation May 28, 2010 Slide 47

43 Can harmonics create problems? Harmonics IEC , THD < 3.0%, Odd.. Even.. IEC China, GB/T IEEE, THD < 1.5 %, Odd, even, current.. Communication systems and modern remote metering devices (Turtle) Overheating of power transformers May 28, 2010 Slide 48

44 Harmonics Network DFIG FPC NODE PL33-W5B U POS. p.u / SQRT[3] kv NODE PL33-W6A U POS. p.u / SQRT[3] kv NODE PL33-W4A U POS. p.u / SQRT[3] kv NODE PL33-W3A U POS. p.u / SQRT[3] kv 6,00 50, ,00 40, , , , , ,00 1,00 10, ,00 0, FREQUENCY HZ May 28, 2010 Slide 49

45 ABB Smart Grid Wind power integration in networks ABB Solutions Shunt banks Small SVC Full rated SVC SVC Light (STATCOM) SVC Light Energy Storage Hybrid solutions May 28, 2010 Slide 50

46 Mechanical switched capacitors from ABB ABB Solutions Q-bank - open capacitor bank SIKAP - enclosed capacitor bank ABBACUS containerized capacitor bank kv EMPAC- enclosed capacitor bank 36 kv May 28, 2010 Slide 52 CHARM filter banks

47 SVC Light with energi storage - applications ABB Solutions ABB Group February May 28, , 2010 Slide Slide 53 53

48 SVC Light Energy Storage ABB Solutions Energy storage connected on DC-side of converter (SVC Light) Size depends on power level and duration Charge energy equal to load energy Focus on dynamic, manages: High number charge and discharge cycles High Power at medium duration Chosen high performance battery as energy storage May 28, 2010 Slide 54

49 SVC Light Energy Storage ABB Solutions SVC Light First project in 1999 for flicker mitigation of electric arc furnace In total 12 project for both industry and utility applications Power range up 164 Mvar, direct connected without transformer up to 35kV grid SVC Light Energy Storage First project in 2009 Energy Company in UK System Voltage 11 kv Reactive Power: 600 kvar inductive 600 kvar capacitive Active Power: 200 kw during 1 hour 600 kw (short time) Picture of the new Li-ion battery after testing, October 2008 May 28, 2010 Slide 55

50 SVC Light med energilager ABB Solutions Cell Module Room String Storage ABB Group February May 28, , 2010 Slide Slide 56 56

51 SVC Light med energilager ABB Solutions 50 m 65 m Typisk layout för 20 MW under 15 mininuter och +/-30 Mvar kontinuerlig ABB Group February May 28, , 2010 Slide Slide 57 57

52 AC Offshore system issues Lightning Bergeron study, n*d Power Electronics ABB Off-shore Solutions Thermal Cyclic rating Grounding? EMTDC model from SANDYS Gearbox BLASIG Booster PQ working area Platform Xk Weight Fault current d d Redundancy PCC Compensation (Localization?!) -Static -Dynamic -SVC vz STATCOM -SVC Light/DynaPow -MINICOMP Ride through Cable parameters Cable cost -Laying/burying -Trench width Harmonics Energization Shield overvoltage Separate 600 V auxiliary grid? Grounding -System -Equivpotential Aux. Power -Diesel -Energy Storage Fault detection -Ground faults -Short Circuit Currents -Need for further protection? Protective capacitor Circuit Breaker -Vaccum Surge arresters Collection Grid Switchboard -Energizing -Normal Operation Voltage level RMU 36 kv Vt and ferroresonance ABB do not have a voltage divider above 24 kv Protective capacitor Type, ratio RC-protection Cable Shielding May 28, 2010 Slide 62

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