European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Wind Energy...

European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens

Wind Energy Penetration in Islands: Limitations and Prospects

N. Hatziargyriou S. Papathanassiou, T. Chaviaropoulos, I. Tsipouridis

NTUA CRES PPC


Island Systems


Installed Wind Power(ΜW)

Small Hydro (MW)

Biomass(MW)

PV(kW)

Hellenic Interconnected system

341 61 20.6 105

Crete 87 0.6 0.4 442

Cyclades 5.4 0 0 182

Dodecanesse 9.9 0 0 37.5

Rest Aegean Islands

26 .1 0 0 73

Total islands 128.4 0.6 0.4 735

Total 469.4 61.6 21 840

RES in GreeceRES in Greece (1) (1)


With authorization

Wind Power(ΜW)

Small Hydro (MW)

Biomass+Geothermal

(MW)

PV(kW)

Hellenic Interconnected system

3039.4 348.59 40.5 760

Crete 132.3 0 0 650

Cyclades 33.25 0 0 0

Dodecanesse 68.5 0 0.5 0

Rest Aegean Islands 17.15 3.8 8 100

Total islands 251.2 352.39 8.5 750

Total 3290.6 352.39 49 1510

RES in GreeceRES in Greece (2) (2)


– Small isolated Power system –2MW.

– 11% Annual RES penetration –Wind & PV

– Up to 100% instantaneous RES Penetration

Kythnos Island


Number Type of Unit Capacity

5 Diesel units 5*400=2000kW /2500kVA

1 Wind Turbine 500kW

5 Wind Turbines 5*33=165kW

1 PV Power station 100kW

1 Battery Bank 400kWh/500kW

1 Phase Shifter 600kVA

1 Compensation bank 8*100=800kVAr

Kythnos Power System-todayKythnos Power System-today


Crete Island

Largest isolated power system in GreeceLargest isolated power system in Greece3 Power Stations (Chania,Linoperamata,Atherinolakos)-3 Power Stations (Chania,Linoperamata,Atherinolakos)-26 thermal units, Peak 540 MW(2004), 26 thermal units, Peak 540 MW(2004), 87.1MW Wind capacity-Wind power penetration 10%87.1MW Wind capacity-Wind power penetration 10%


Crete System Single-Line Diagram


W/F Production 1993-2000 [KWh]

0

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100.000.000

150.000.000

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1993 1994 1995 1996 1997 1998 1999 2000

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all

ed

W/P

Ca

pa

city

[M

W]

W/F Production[MWh]

Installed W/F Capacity[MW]

Ye

arl

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rod

uc

tio

n [

KW

h]

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2%

5%

10%


Penetration during the day of max. inst. output ( Dec.28.2000)

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MW

]

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Load W/P Penetration

Time


Rokas W/F output (13 May 1998)

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Rokas W/F output ( 20 May 1998 )

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Frequency and production due to Gas Turbine Outage

.


Summary of Experience from Wind Power Penetration in Crete

High efficiencies (Capacity Factor in 2000:37,33%)

Stable output but with serious exceptions

Normal Voltage fluctuation at connecting W/F bus

Higher yields during summer months but lower,or zero, at evening peaks

No problem for Flicker or Harmonics

Economical considerations.


Large Scale Penetration of Increased Wind Power in Island Systems

• Wind Power - Intermittent Power Source• Wind Power – partly non-controllable

Effects→ Operation with increased uncertainty, requirements for

reliable short-term forecasts of renewable source production.

→ Effects on power system security both steady-state and dynamic, inability of conventional directly coupled Wind Turbines to provide ancillary services, requirements for on-line security assessment.

→ Effects on economic operation → Power Quality ???


Fault Ride-Through Capability• Modern WG are

required to remain connected during a fault

• Various standards for voltage dips to be sustained

Frequency Requirements?


CARE&MORE CARE EC Projects: Advanced Control Advice for Power Systems with

Large-Scale Integration of RESJOULE JOR3-CT96-0119 & ENERGIE ERK5-CT1999-00019

• Minimise production costs through unit commitment and on-line economic dispatch of both conventional and RES also considering market and increased security.

• Provide short-term forecasts of load and wind for short-term (0-8 hr) and medium-term horizon (4-48 hrs).

• Maximise power system security by on-line security assessment modules, that supervise scheduling of the power units and monitor the system security margin. Also provide corrective control actions.


OPERATOR

SCADA system

DATA-BASE

SCHEDULER

SECURITYASSESSMENT

RENEWABLESFORECASTING

MAN-MACHINEINTERFACE

SECURITYMONITORING

ECONOMICDISPATCH

UNIT COMMITMENT

LOAD FORECASTING

The CARE System Architecture


Execution Cycles of MORE CARE

For Crete

H=48 hrs, h=4 hrs,

t1=1 hr, t2=20 min

START

Load & renewable power forecasts ( H

D hours ahead)

Unit Commitment ( H1

hours ahead)

Dynamic Security Assessment

Economic Dispatch

Set-Points of Power Units

Ev

ery t1 h

ou

rs

Ev

ery t2 m

inu

tes

Load & renewable power forecasts (h hours ahead)

Dynamic Security Monitoring

Unit Commitment ( hD

hours ahead)


Current System Operation and Economic DispatchCurrent System Operation and Economic Dispatch

Wind ParksWind ParksLoadsLoads

Current ProductionCurrent ProductionEconomic DispatchEconomic Dispatch


• Off-line execution of Economic Scheduling functions assuming:– Spinning Reserve at least equal to wind power – no wind

power forecasting– Spinning reserve at least equal to 50% of wind power – 50%

maximum forecasting error – Spinning reserve at least equal to 20% of wind power to face

very short wind fluctuations – very advanced WF with 20% maximum forecasting error.

– Evaluation of economic impacts

Economic Appraisal of Wind Power Forecasting


More accurate wind power forecasting reduces operating costs as follows:

• Monthly cost savings with thermal spinning reserve equal to 50% of wind power

1.8-3.5% (163-480 kEuro)• Monthly cost savings with thermal spinning reserve equal to

20% of wind power 2.3-5.3% (217-758 kEuro)

Economic Appraisal of Wind Power Forecasting - Results


• Unit Commitment Average gain 3.1%

• Economic Dispatch Average gain 1.7%

Economic Scheduling EvaluationEconomic Scheduling Evaluation


Relative gain provided by GA Economic

Scheduling Functions

ED OPF UC A UC B August 2001 1.7 1.67 2.2 3.15 September 2001 1.3 1 1.1 2.75 October 2001 0.6 1.02 3.85 3.5 November 2001 0.1 0.58 3.44 5.73 January 2002 2.35 2.73 3.76 3.22 February 2002 0.95 1.30 5.2 6

Economic Scheduling EvaluationEconomic Scheduling Evaluation


Actual Operation Proposed Operation

Dynamic Security EvaluationDynamic Security Evaluation


Short term flicker (Pst) at W/P bus of Sitia S/S ( 12 Aug. 1998 )

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Long term flicker (Plt) at W/F bus of Sitia S/S ( 12 aug. 1998 )

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PROJECT: Integration of Wind Turbines into Electricity Supply Networks with Limited Power Transportation Capacity –Wiring (JOR3-CT98-0245)

Electrical network of the Greek island Samos

VESTASWINDMATICNEG MICONNEG MICON


Frequency behaviour of the island grid of Samos during one week


Diesel generator production during 13 days


The measurement campaign gave some unexpected results:

Most important is the fact that the voltages are highly distorted in

the flicker producing frequency region, due to firing harmonics of

the power station diesel engines. This background distortion is large

enough to completely mask the effect of the flicker emitted by the

WTs. The connection of the WTs leaves more or less unaffected the

overall flicker levels, and in certain cases even reduces them.

The effect of the Vestas wind turbines on the frequency spectrum

of voltage and power at the diesel power station was investigated.

The same spectrum of voltages occurs with and without the wind

turbines.


Voltage PSD before cut-in of WTs

Voltage PSD after cut-in of WTs

Firing of diesel engines


CONCLUSIONS

Wind power installations in islands provide economical benefits compared to diesel

Increased requirements for robust Wind Turbines equipped with Low Voltage Ride Through capabilities and able to withstand frequency varaitions

Need for advanced control systems to deal with optimal operation and management of power systems with large integration from wind power.

Application of the MORE CARE control software on Crete has shown clear economic gains and timely warning for more secure operation.

Flicker levels do not seem to be affected by the operation of WTs.

European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Wind Energy...

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Transcript of European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Wind Energy...