Integrating Multiple Microgrids into an
Active Network Management System
Presented By: Colin Gault, Smarter Grid Solutions
Co-Authors:
Joe Schatz, Southern Company
George Gao, Southern Company
George Simard, SIMARD SG
Bob Currie, Smarter Grid Solutions
February 3rd 2015
The “Project”
• Regional Microgrid Control: Research and
Development
• Multi-year project between Southern Company and
Smarter Grid Solutions
• Develop microgrid control platform using Active
Network Management technology
• Phased Approach
– Phase 1: Use Case Definition and Simulation of Active
Network Management (Complete February 2015)
– Phase 2: Trial deployment of Active Network
Management at test site (Summer 2015)
– Future Phases: Phased implementation of microgrid
functionality (2016)
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Active Network Management
• End-to-end autonomous control solutions
• Real-time operating system providing deterministic control
over distributed energy resources
• Safe, secure and reliable method to increase hosting
capacity of electricity grid
• Complements existing SCADA and Protection systems
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Active Network Management
Reliable - Deterministic - Repeatable
Scalable - Open Standards
Data Historian
DMS
DERMS
Generator
Generator
Energy
Storage
System
Energy
Storage
System 4
Active Network Management
• Applied active network management to the following use cases in live
deployments
– Management of power flow constraints
– Management of voltage constraints
– Management of distributed generation contributing to transmission system
constraints
– Smart electric vehicle charging
– Demand Response (domestic / commercial)
– Day ahead scheduling of controllable demand to coincide with renewable
energy production to support frequency stability
• Interfacing with range of Distributed Energy Resources
– Wind | Solar | CHP |Building Management System | Electrical Energy Storage
Thermal Energy Storage | Electric Vehicle Charging Equipment
• Future development could include interoperability with automatic
restoration and volt-var control solutions leveraging DER control
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Adaptation to Incorporate Microgrids
New layer of control: Microgrid Controller
Data Historian
ANM Application
DMS
DERMS
Microgrid Controller
Microgrid Controller
Microgrid Controller
Generator
Facility Microgrid
Generator
Energy
Storage
System
Circuit Microgrid
Energy
Storage
System
Substation Microgrid
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Layers of Microgrid Control
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Use Case Definition
• Create use cases across
three modes of operation
– Interconnected
• Microgrids interconnected
with area power system
– Transition Management
• Microgrid transitioning into
and out of islanded operation
– Islanded
• Microgrid operating as an
island
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Interconnected
Regional
Microgrid
Constraint
Constraint
Management Management
Ancillary
Services
Energy
Management
DER
Controller
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Transition Management
Planned
Islanding
Regional
Microgrid
Unplanned
Islanding
Regional
Microgrid
Reconnection
Regional
Microgrid
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Islanded
Frequency /
Voltage
Control
Energy
Management
Black Start
DER
Controller
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Modelling and Simulation
• Model of 12.47 kV Feeder with
existing Solar PV: Peak demand
8MW
• Large proportion of feeder load
is a single industrial customer
• Battery Energy Storage System
to be installed later this year
1 MW Solar PV
1MW, 2MWh ESS
• Steady State Load Flow
simulations using CYMDIST
• Interconnected and Islanded
Microgrid Use Cases Explored
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Feeder Demand
Measured at Substation
• Interconnected
– Use of the Energy
Storage to minimize total
feeder maximum
demand
1 MW Solar PV
1MW, 2MWh ESS
– Use of the energy
Storage to minimize
ratio between total
feeder maximum and
minimum demand
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• Islanded
Microgrid Isolation
Points
– Use ESS profile
generated during
simulation of
interconnected use case
– Maintain balance
between load and
generation on section of
feeder
– Loads chosen are nonindustrial customers
25 kVA
1 MW Solar PV
1MW, 2MWh ESS
500 kVA
25 kVA
Microgrid
Loads
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• Extended Island
Microgrid Isolation
Points
– Extend microgrid
boundary
1500 kVA
25 kVA
1 MW Solar PV
– Include additional
load to stretch
capability of
microgrid resources
1MW, 2MWh ESS
500 kVA
25 kVA
Microgrid
Loads
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Method: Interconnected
• Input Data
– One year (2014) of hourly data for feeder
measured at substation
• Calculate “average day” profile for feeder
• Generate a 24 hour schedule for battery to
reduce peaks and troughs and apply to 365
days
• Apply upper and lower thresholds that trigger
unscheduled charge/discharge of battery
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Method: Islanded
• Starting position uses results from interconnected
study
• For every hour in the year calculate the maximum
duration that an island could be sustained if an
“event” was to occur
– Match Battery and PV to load on section of feeder
– Excess energy from PV charges battery
– Shortfall in PV discharges battery
• Assumes battery inverter has capability to
maintain frequency and voltage stability
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Results
• Interconnected
– Yearly peak demand reduced by 200 kW
– Yearly minimum demand increased by 150 kW
• Islanded: Peak load 500 kW
– Islanding achievable 6888 hours out of 8760
– Average duration: 30 hours
• Extended Island: Peak load 2,000 kW
– Islanding achievable 1584 hours out of 8760
– Average duration : 7.6 hours
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Battery Profile
Final SOC (MWh)
Final Power Profile (MW)
0.3
2
1.5
0.2
1
0.1
0.5
0
0
0
2
4
6
8
10
12
14
16
18
20
22
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-0.5
-0.1
-1
-0.2
-1.5
-0.3
Typical Day
-2
Original Profle (MW)
With Battery (MW)
7
6.5
6
5.5
5
4.5
4
0
2
4
6
8
10
12
14
16
18
20
22
24
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Conclusions
• Shape of profile with long peaks and deep troughs
makes it difficult for battery to reduce peak and
increase trough significantly during interconnected
mode when following a daily schedule
• May be more appropriate to use battery during
instantaneous events using triggers as opposed to
implementing daily schedule
• Islanding results show promise in being able to sustain
a microgrid for significant period of time to reduce
interruptions to non-industrial customers on feeder
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Project Next Steps
• Deploy Active Network Management solution
to perform field trial of use cases and compare
results
• Phased roll-out of microgrid functionality at
pilot site and/or other appropriate sites and
development of inter microgrid control
philosophies
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Proposed architecture
for trial deployment
MP
MP
1 MW Solar PV
1MW, 2MWh ESS
MP
Power Flow
Measurement Point
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Presented by: Colin Gault,
Principal Consultant,
Smarter Grid Solutions
E-mail:
cgault@smartergridsolutions.com
Phone:
+1 (718) 260 3603
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