an overview of grid requirements in denmark and … overview of grid requirements in ... oltc comp...

An Overview of Grid Requirements in Denmark and the DTU Advanced Grid Test Facility at Østerild

Tom Cronin

DTU Wind Energy

Technical University of Denmark

DTU Wind Energy, Technical University of Denmark

DTU Wind Energy

2 14 June 2013

Composites and Materials Mechanics

Materials Science and Characterisation

Fluid Mechanics

Test and Measurements

Wind Turbines Structures

Aerolastic Design

Meteorology

Wind Energy Systems

Fluid Dynamics

Composite Mechanics

Materials Research Division

Wind Energy Division

Wind Energy Division

> 230 staff members


DTU Wind Energy

3 14 June 2013


DTU – Excellence since 1829

4

MISSION DTU will develop and create value using the natural sciences and the

technical sciences to benefit society

14 June 2013


Overview of this presentation

• DTU Wind Energy

• What’s the reason for me being at this workshop?

• The Danish grid requirements

– Who, what and how?

• The DTU Advanced Grid Test Facility

– Why, what, where and when?

5 14 June 2013


Danish grid codes

• ”Technical regulation 3.2.5 for wind power plants with power output greater than 11kW”

• Issued by the Transmission System Operator: Energinet.dk

• Website: www.energinet.dk

• Due to history of Danish wind power, the Danish grid codes have been at the forefront

• Comprehensive grid codes are needed if have high penetration

• Occasions in Western Denmark when wind power exceeds consumption

• National annual average around 25%

• Average wind production to increase to meet the goal of 50% by 2025.

• Grid codes need to keep in front of this development.

6 14 June 2013

http://www.energinet.dk/

DTU Wind Energy, Technical University of Denmark 14 June 2013 7

• Tolerance of voltage and frequency deviations

– Normal operation

– Abnormal operation

• Electricity quality

• Control and monitoring

• Protection

• Data communication and exchange of signals

The Danish Grid Codes - structure

All diagrams courtesy of Energinet.dk


“A wind power plant must be able to withstand frequency and voltage deviations in the point of connection under normal and abnormal operating conditions while reducing the active power as little as possible.”

Tolerance of frequency & voltage deviations

Normal Operation


Tolerance of frequency & voltage deviations

Abnormal Operation


The grid codes consider:

• Voltage fluctuations

– Rapid voltage changes

– Flicker (continuous and switching)

• High frequency currents and voltages

– Harmonics

– Inter-harmonics

– Disturbances greater than 2 kHz

Electricity quality


Control & Monitoring: Active power control

• Frequency control

– Remotely set droop curves dictate active power vs. frequency

11 14 June 2013


Control & Monitoring: Active power control

• Absolute production constraint

– Used to prevent overload of system/power lines

• Delta production constraint (spinning reserve)

– To create a reserve in preparation of frequency control

• Power gradient constraint

– To prevent system instability dues to fast and large changes in wind speed

12 14 June 2013


Active power control: example

13 14 June 2013

Deactivation of delta and

activation of gradient

production constraint


Active power control limits

• Must be able to down-regulate from 100% to 20% of power plant capacity

• Near cut-out wind speed: additional control

14 14 June 2013


Control & Monitoring: Reactive power control

• Q control

– Reactive power is independent of active power

• Power factor control

– Reactive power is proportional to active power

• Voltage control

– Controls the voltage at the voltage reference point , wrt reactive power output

15 14 June 2013


Reactive power control limits

16 14 June 2013


Grid codes and the DTU Grid Test Facility

• In 2011, our feasibility study looked at

– Global grid codes

– Manufacturers’ requirements

– Developers’ needs

– Research areas

– Equipment alternatives

• Conclusion

Optimum facility combines a converter-based unit and an impedance-based unit

• The DTU Advanced Grid Test Facility

– 10MW, upgradable to 16MW

– Grid codes – verification of compliance esp. frequency control

– Wind turbine testing/development/proving

– Development of future standards and grid codes

– Simulation models – validation

– Wind farm testing

18 14 June 2013

Vestas Siemens Wind Power DONG Energy Vattenfall ABB Siemens DTU Aalborg University


Wind Farm Performance Requirements

BLADE

DT

GEN

CONV

XFR

SG

CO

N

CO

N

WTG

CO

N

MV ARRAY CABLES

Wind Farm TSO Interface. Grid code requirements apply HERE

Set-points

SUBSTATION MV SG

HV GRID (TSO)

Wind BLADE

DT

GEN

CONV

XFR

SG

CO

N

CO

N

WTG

CO

N

Wind BLADE

DT

GEN

CONV

XFR

SG

CO

N

CO

N

WTG

CO

N

Wind

SUBSTATION TRANSFORMER

SUBSTATION HV SG

OLTC

COMP

SS

CO

NTR

OL

SC

AD

A

WTG

CO

NTR

OL

WTG feedback

CON

CON

14 June 2013 19


Contract structures…

BLADE

DT

GEN

CONV

XFR

SG

CO

N

CO

N

WTG

CO

N

MV ARRAY CABLES

Set-points

SUBSTATION MV SG

HV GRID

Wind BLADE

DT

GEN

CONV

XFR

SG

CO

N

CO

N

WTG

CO

N

Wind BLADE

DT

GEN

CONV

XFR

SG

CO

N

CO

N

WTG

CO

N

Wind


SUBSTATION HV SG

OLTC

COMP

SS

CO

NTR

OL

SC

AD

A

WTG

CO

NTR

OL

WTG feedback

CON

CON

Grid Code

14 June 2013 20


Wind Farm Test - scope

BLADE

DT

GEN

CONV

XFR

SG

CO

N

CO

N

WTG

CO

N

MV ARRAY CABLES

Set-points

SUBSTATION MV SG

HV GRID

Wind BLADE

DT

GEN

CONV

XFR

SG

CO

N

CO

N

WTG

CO

N

Wind BLADE

DT

GEN

CONV

XFR

SG

CO

N

CO

N

WTG

CO

N

Wind


SUBSTATION HV SG

OLTC

COMP

SS

CO

NTR

OL

SC

AD

A

WTG

CO

NTR

OL

WTG feedback

CON

CON

Physical Hardware Real Time Simulation Grid Emulation

Legend:

14 June 2013 21


Overall schematic

TEST STAND 3, etc…

22 14 June 2013

GRID EMULATOR

MAIN TRANSFORMER

TEST STAND 1

TEST STAND 2

MV SWITCHGEAR

TO PUBLIC GRID

Test Centre switchgear allows

turbines to be connected to the grid

either directly or through the Test

Facility

The Test Facility grid emulation equipment allows

tests to be performed without disturbing the main public

grid

SHORT CIRCUIT TEST UNIT

The Test Facility short circuit

equipment can also be coupled in and out to

individual turbines

TEST CENTRE

TEST FACILITY


To be located at the Danish National Test Centre for Large Wind Turbines, Østerild

23 14 June 2013

Courtesy of Siemens Wind Power

Test Centre: •Opened Oct 2012 •For turbines up to 250m height •Up to 16MW Grid Facility: •€4M secured •Further funding negotiations •Transportable •Ready ‘mid 2015’

an overview of grid requirements in denmark and … overview of grid requirements in ... oltc comp...

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