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Contents
Distribution grid - utility of Ulm High penetration of PV in low voltage grid Grid operators point of view Test site
Definition Measurements Potential
Measured effects of a high PV penetration to a communal low voltage - - PowerPoint PPT Presentation
Measured effects of a high PV penetration to a communal low voltage - - PowerPoint PPT Presentation
T 2nd Inverter and PV System Technology Forum 2012 Measured effects of a high PV penetration to a communal low voltage grid of Ulm Holger Ruf Gerd Heilscher Florian Meier 1 Contents Distribution grid - utility of Ulm High
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City of Ulm
Highest church tower in the
world
Number One in the
German Solar Bundes League
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ULM
Source: www.wolframalpha.com tourismus.ulm.de
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Key Figures of the Distribution Grid
Utility of ULM, Germany
Low voltage grid
252 km aerial line 1446 km cable 5523 transformers 49,771 loads 332 km² grid area > 200 000 inhabitants
Load
110 MW on
summer Sundays
220 MW maximum
Source: www.swu.de, EEG Anlagenregister, October 2011
86 MW complete, 42 MWp PV in low voltage
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Feed in to Grid greater than Load
Utility of Ulm, Germany
20.000 40.000 60.000 80.000 100.000 120.000 140.000 160.000 180.000 200.000 220.000
1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020
Grid Load kW
Solar Power (EEG) Biomass (EEG) Hydro Power (EEG)
Real Estimate
Max Load
Max Load Sunday Feed in greater than load
Source: www.swu.de, EEG Anlagenregister, August 2011, own calculation 5
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Grid Operators Point of View
Solar power is driving day to day grid upgrades Forward looking planning impossible today Drafted budget for transformer exchange
already used in first half of the year
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First test site
7 ZSW-BMU_Quer 7
- > 130 houses
- 17 PV, total ~200kWp
- 1 transformer (630kVA)
- 0,2 km²
Holger Ruf
Only 17 PV Systems on the 130 Roofs up to now
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First test site grid measurement
Voltage and
Power
1 s resolution 10 channels Large memory
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+ =
0.176 km² area 630 kVA
transformer
8 outgoing lines > 130 Loads 17 PVs (~200kWp)
Real time
measurements
Since 30th March
2011
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Active Power
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Voltage
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Active Power
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Voltage
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Solar Potential of Test Site – Today and Tomorrow
Maximum development
Today:
133 Houses 200 kWp / 17 PV = ~12kWp/House
Tomorrow:
133 Houses conservative (5kWp/House) 650 kWp actual (12kWp/House) 1560 kWp
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Solar Potential of Test Site – Tomorrow Effects
Problems without grid development Violation of voltage tolarance according to EN
60038 (± 10% Vn)
Violation of fast voltage transient according to
VDE-AR-N 4105 (≤ 3% Vn)
Reduced life time of transformers caused of
thermal overload
Increase of power electronics
electromagnetic compatibility (EMC) problems
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PV influence on the grid (1)
Voltage tolerance
violation
Reversal load flow
Source: TU München, Prof. Witzmann 15
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PV influence on the grid (2)
Thermal
- verload
transformer and cable possible
PPV/STr >1,5
increase ageing
Source: TU München, Prof. Witzmann 16
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ENDORSE - Local solar power forecast
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Consumption Generation 1h predicted Generation 122 kW 250 kW 5 kW 5 minutes 3x5 km/pixel Clouds detected
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Next Steps to Smart Solar Grid
- Determination
- f solar potential
for every roof / grid access point
- Calculation of
energy flow
- Evaluation of
influences to the grid
- Detailed plan/cost
for grid upgrade
- Smart Metering
- Solar power forecast
- Load management
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Contact
Florian Meier SWU Netze GmbH
- Karlstr. 1
D-89075 Ulm florian.meier@swu.de
- Prof. Gerd Heilscher, Holger Ruf
Ulm University of Applied Sciences Eberhard Finckh Str. 11 D-89075 Ulm heilscher@hs-ulm.de ruf@hs-ulm.de
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