Frankfurt (Germany), 6-9 June 2011 W. Niederhuemer – Austria – RIF Session 4 – Paper 1100 1...

1

Frankfurt (Germany), 6-9 June 2011

W. Niederhuemer – Austria – RIF Session 4 – Paper 1100

PROBABILISTIC PLANNING FOR A HIGHER INTEGRATION OF

WIND TURBINES TO MV DISTRIBUTION NETWORKS

Walter Niederhuemer

Karl Derler

Linz Strom Netz GmbH

2



Introduction

Feed in by onshore wind turbines into MV-grids is a particular challenge for the DSO Requests for connections primarily for several wind turbines or

small wind farms Power range of a few MW Connections distributed across the same part of the MV-

distribution network

To enable the feed in and guarantee the power quality Reduction of the installed feed in power is necessary Extending the distribution network

3



Introduction

Producer and DSO with different optimum Producer

Deliver full feed in power at any time Increase the energy output and thus to optimize the return Low direct grid connection costs

DSO Keep the network cost as low as possible

To support the objectives of the EU and to enable more feeding in, it is necessary To find an overall economic optimum To find a compromise between network investments and

produces energy quantity

4



Method of calculation Probabilistic calculation Taking into account the

statistical behavior of Output voltage in the substation Current in the branch Feed in power of the wind turbine

5



Result of the conventional assessment

Reduction of installed feed in power to 2,2 MW is necessary Alternatively, 0,5Mio€ investment to the grid for a 3km long MV cable

Selected network 1,2MW wind turbine +

250kW biogas plant connected

New 2MW wind turbine is planned

Connection via 17,5km overhead line 95mm² Aldrey

Conventional assessment Peak load with and

without feeding Off-peak load with and

without feeding

6



Result of the probabilistic calculation

Installed wind turbine power 3,2MW

Voltage exceeds the voltage limit only for a few hours.

Theoretically generated annual amount of energy about 3.000 MWh

With active power control 0,03% not feed in energy Reduction of active power

up to max. 1370kW

Cumulated relative frequency distributionvoltage at PCC

26,1

8 26,4

1

26,9

0

25,9

6

27,4

5

25,0

25,5

26,0

26,5

27,0

27,5

28,0

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Cumulated relative frequency

Vo

ltag

e [k

V]

Maximum acceptable voltage in the MV-network

feed in power at PCC: 3,2 MW wind turbine

Annual revenue loss is less than 100€ (with feed-in tariff of 9,6ct/kWh)

7



Result of the probabilistic calculation

Theoretically generated annual amount of energy about 7.000 MWh

With active power control 5% not feed in energy Real feed in energy

6.650 MWh Reduction of active power

up to max. 3,8MW (50% of installed feed in power)

2 times higher energy yield without additional grid investments

If a not feed in energy amount of 5% is acceptable for producers 7,5MW wind turbine power could be installed at the PCC

Yearly earning of energy of on-shore wind turbines and loss because of control or switch off if voltage level is too high

2.000

3.000

4.000

5.000

6.000

7.000

8.000

3000 4000 5000 6000 7000 8000 9000

installed wind generation power [kW]

fee

d i

n e

ne

rgy

[M

Wh

]

theoreticaly feed in energy [kWh] real feed in energy [kWh] (active power control)real feed in energy [kWh] (switch off)

~5% of not feed in energy

8



Conclusion

Probabilistic planning allows a better simulation of real network conditions

More than 2 times higher generation capacity by minimal network costs

Acceptance by producers of a certain amount of not feed in energy is necessary

Need of construction cost contribution for future grid investments

Need of suitable legal frameworks

Frankfurt (Germany), 6-9 June 2011 W. Niederhuemer – Austria – RIF Session 4 – Paper 1100 1...

Documents

Transcript of Frankfurt (Germany), 6-9 June 2011 W. Niederhuemer – Austria – RIF Session 4 – Paper 1100 1...