This document presents a novel approach called LV4MV that determines optimal voltage ranges at the medium voltage (MV) and low voltage (LV) levels of distribution grids. LV4MV sets admissible MV voltage ranges based on the available flexibility from distributed energy resources (DER) connected downstream at the LV level. The goal is to minimize network losses while satisfying grid codes by allowing larger MV voltage ranges where possible through controlled DER response. Test results on real MV and LV networks show how MV ranges can be increased by activating DER flexibility in steps as needed to ensure compliance of LV voltage profiles.

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Nodes
Voltage(pu)
Voltage profile along the LV network, h=1.30pm
Phase 1
Phase 2
Phase 3
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Voltage(pu)
Voltage profile in the MV network, h=1.30pm
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Voltage(pu)
Voltage profile along the LV network, h=1.30pm
Phase 1
Phase 2
Phase 3
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CIRED 2015 poster session – paper n° 1045 – session n° 3
LV4MV: A CONCEPT FOR OPTIMAL POWER FLOW MANAGEMENT
IN DISTRIBUTION GRIDS, USING DER FLEXIBILITY
A novel approach of MV voltage plan setting based on LV voltage deviation tolerance assessments
Emmanuelle VANET
Raphaël CAIRE
Nouredine HADJSAID
Univ. Grenoble Alpes, G2Elab – France
Gaspard LEBEL
Stéphane BEDIOU
Alain GLATIGNY
Schneider Electric – France
The large penetration of Distributed Generation among the distribution grids engenders voltage
deviations in both Medium and Low Voltage levels. To cope with it, Distribution System Operators
can either use network reinforcement, or voltage regulation through management of local active
and reactive powers of the Distributed Energy Resources. LV4MV aims to prepare the optimization
of MV network operation, determining the admissible voltage ranges at the critical MV/LV substations,
depending on the downstream LV networks and their available flexibility.
Constraint management, Distributed Energy resources (DER), Distributed
Operation, DSO ancillary services, Short-term local flexibility, Voltage regulation
KEY
WORDS
emmanuelle.vanet@g2elab.grenoble-inp.fr Emmanuelle-Vanet
PROCESSPROBLEMATIC
MV network
operation
optimization
LV voltage
constraints
?
MV voltage
constraints
ok • Or enlarge these admissible
MV ranges by activating DER
down the MV/LV substation
until the network satisfies the
Grid codes
• Perform a MV OPF to optimize network losses with these newly defined MV
voltage ranges
• Calculate at the critical MV/LV substations, the MV range that guarantee that the
occurrence of any MV voltage value contained within this range will not induce a LV
voltage deviation of more than ±10% at any point of the LV feeders supplied.
1
3
2
Network losses minimization on a real 2-feeders MV network
MV admissible voltage ranges determination on a real
unbalanced LV network
Step-by-step DER flexibility activation process
OR LV DER
ACTIVATION
TO INCREASE
MV RANGES?
3
Vadm=[0,91;1,035]
23 x 12kW residential consumers
65% GED
Vadm=[0,91;1,07]
23 x 12kW residential consumers
30% GED
ErDF profiles, S26,j4 (last week of June, 2011)
At MV/LV transformers…
Are voltage profiles
compliant down the LV
feeders?
0,91 pu
1,035 pu
1 ADMISSIBLE MV RANGES
0,91 pu
1,07 pu
CHANGE
OLTC
POSITION?
1,04 pu
-0.01 -0.005 0 0.005 0.01 0.015 0.02 0.025
0
10
20
30
MV admissible voltage ranges with respect to DER activation
Flexibility amount (pu)
BidPrice(c€)
0.9
1
0.9
0.92
0.94
0.96
0.98
1
1.02
1.04
0.9
0.92
0.94
0.96
0.98
1
1.02
1.04
0.9
0.92
0.94
0.96
0.98
1
1.02
1.04
0.9
0.95
1
1.05
MVadmissiblevoltagerange(pu)