Transcript Intelligent distribution substation improves power quality

Frankfurt (Germany), 6-9 June 2011
Intelligent Distribution Substation
improves power quality
Irina Melnik – the Netherlands – Session S2 – 0665
Frankfurt (Germany), 6-9 June 2011
Need for new technologies
MV


LV

Load
Power
MV
Generation
Micro
CHP
Micro
CHP
Micro
CHP
Load
Power



PV
Fluctuating loads
Distributed generation
Changes in power flows
Larger voltage variations
Uncertainty for planning
Complex grid operation
LV
PV


Monitoring and control
New technologies
Frankfurt (Germany), 6-9 June 2011
Intelligent distribution substation (IntDS)
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Developed by a consortium of Dutch industries
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Installed and tested in the grid of DSO Alliander
Additional functions of the IntDS:
 Monitoring
 Control
 Improving Power Quality
Frankfurt (Germany), 6-9 June 2011
“Intelligent” components of IntDS
Smart
Transformer
Electricity storage system
with bidirectional inverter
Measurement system
Frankfurt (Germany), 6-9 June 2011
IntDS implementation
District with large amount of
micro Combined Heat Power
at customers
Frankfurt (Germany), 6-9 June 2011
Test program
Power Quality improvement by the IntDS:
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Voltage control
Reduction of harmonic distortion
Reduction of flicker
Mitigation of voltage dips
Frankfurt (Germany), 6-9 June 2011
Voltage control
Performed by Smart Transformer:

Electronic tap changer ensures
a constant voltage level on the LV rail
of the IntDS.
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The voltage control set-point
has to be determined to achieve
the optimal voltage level on PCC’s
of all LV customers.
Smart
Transformer
Frankfurt (Germany), 6-9 June 2011
Voltage control – test results
LV bus-bar
control
U avg
U max
U min
no control
LV customer
1
2
control
3
1
2
3
no control
Frankfurt (Germany), 6-9 June 2011
Harmonic distortion reduction
Performed by ESI
(Electricity storage inverter) :

Resistive harmonic damping

Passive harmonic damping
The filter capacitors of the ESI take
part in the filtering of harmonics.
Electricity storage system
with bidirectional inverter
Frankfurt (Germany), 6-9 June 2011
Harmonic distortion reduction – test results
LV bus-bar
no control
control
H03 max
H05 max
H07 max
THD max
no
LV customer
no control
control
no
Frankfurt (Germany), 6-9 June 2011
Voltage dips mitigation

Can be performed by:
the Smart Transformer
the ESI (Electricity storage inverter)
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Voltage dips occur only a few times per year
on an LV bus-bar of Dutch distribution substations.
That’s why this functionality is not actively tested.
Frankfurt (Germany), 6-9 June 2011
Flicker reduction (LV side)
Performed by:
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The electronic tap changer of the Smart Transformer
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The flicker reduction control of the bidirectional inverter (ESI)
of the storage system.
Frankfurt (Germany), 6-9 June 2011
Flicker reduction – test results
Plt avg
Pst avg
Plt max
Pst max
LV bus-bar
no
control
LV customer
no
control
Frankfurt (Germany), 6-9 June 2011
Conclusions
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The Intelligent substation has proved to be safe in operation.

The first field test results demonstrate a significant reduction
of voltage variations, harmonic and THD levels both at the
LV bus-bar of the IntDS and at the LV customers.

Further metering and test programs will be performed to set
optimal set-points for control equipments.

The proved principles can be used for area’s with high levels
of PQ distortions.
Irina Melnik – the Netherlands – Session S2 – 0665