Utility Microgrids: Integration and Implementation Challenges

Utility-owned Public Purpose Microgrids

August 2016

Contents

• ComEd Microgrid Pilot Program• Microgrid Controller• Microgrid-Integrated Solar-Storage Technology (MISST)

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In May 2016, ComEd proposed the Next Generation Energy Plan to the Illinois General Assembly which would allow the company to invest up to $250 million in the development of five public purpose microgrids within its service territory

Illinois Medical District (IMD) • Cluster of major hospitals

within a small footprint in the City of Chicago.

• Supports the major health care facilities that provide services to a large number of people within ComEd service territory.

Bronzeville Community • Provides a representative

cross-section of the City of Chicago

• Includes a diverse mixture of facilities and critical loads: Chicago Police Headquarters, health care facilities educational facilities, and private residences.

Chicago Heights Water • Resilient supply to water

pumping and treatment facilities in a small footprint

• Supports water infrastructure for the southern suburbs of Chicago including Chicago Heights, Ford Heights, Homewood, Park Forest, South Chicago Heights, Steger and Crete

DuPage County Complex• Includes administrative

buildings, youth home, county health department, judicial building, sheriff department, highway department, county jail, and emergency management offices

• Provides resilient power supply to support critical operations of a major county

Rockford International Airport

• Support critical facilities for cargo and transportation.

• Rockford airport is a major hub for air cargo and disruption to its operations could have an impact on the economy in Northern Illinois.

ComEd utilized a holistic data driven approach and developed a resiliency metric to evaluate its entire service territory for microgrid pilot installation locations.

For analysis, the service territory was divided into one-mile by one-mile sections outside the city of Chicago and into half-mile by half-mile sections inside the city of Chicago. Each section was then analyzed with a resiliency metric

ComEd Microgrid Pilot Program 3

Bronzeville Pilot AreaThe Bronzeville Community:

• Bronzeville provides a representative cross-section of different customers within the City of Chicago

• Supplied by 9 feeders from 4 different substations.

• Includes a diverse mixture of facilities and critical loads

• Opportunity to cluster the proposed microgrid with Illinois Tech existing microgrid through a Microgrid Controller

• Opportunity to integrate Solar generation and storage through MISST solution.

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Bronzeville Community Microgrid (BCM)Specifications: • Two new UG 12 kV feeders • 2 Substations • >10 MW of Generation and Battery Storage • Distribution Automation • Fiber Optic Network • PMUs • >1,000 customers • 10 MW of load • Interconnection to IIT 12 MW Microgrid

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PC-L#1 PC-L#2 PC-L#3 PC-L#4CB-F11

PC-T#1

Substation 1

CB-IIT

ComEd’s Grid

Gen

Relay

Feeder 11

Bronzeville Community Microgrid IIT Microgrid

VISTA 1

Vista Switch

Switch PC-L

Switch PC-T

Circuit Breaker

Red: Normally Close

Green: Normally Open

VISTA 3

VISTA 4

PC-L#8 PC-L#9PC-L#7PC-L#6PC-L#5

VISTA 2

CB-F9

Substation 2

Relay

Feeder9

New Feeder

29A 324 CUST

9A 155 CUST

96A 91 CUST

24A 255 CUST

50A 251 CUST

PMU-CB11 20A 4 CUST

PMU-V1

PMU T1 (2 modules)

PMU-CB9

Relay

43A 1 CUST

281A 2 CUST

21A 1 CUST

PMU-V2

PMU-V3

PMU-V4

12KV

CHP

5 MW

PV ES

ES

1 MW

1 MW

1.5

MW

Diesel

2 MW

CHP

Diesel

PV

ES

Generation (CHP)

Generation (Diesel)

Generation (PV)

Generation (Energy Storage)

Connection to ComEd

Connection to IIT

ComEd’s Grid Bronzeville Community Microgrid IIT Microgrid

Microgrid Controller Architecture

The BCM Master Controller applies a hierarchical control strategy to ensure reliable and economic operation of the microgrid, and coordinates the operation of switch controllers, distributed generation and storage controllers. A description of the hierarchy is given below:

Distributed ControlCentralized Control

Grid-forming Components Non-Grid-Forming Components

Tertiary Control

Bronzeville Community Microgrid (BCM) Control Architecture

Economic Operation Short-Term Reliability

Economic Demand Response

Unit Commitment and Economic

Dispatch

Islanding and

Resynchronization

Emergency Demand Response

Self-Healing

Primary Control

Secondary Control

Dispatchable Generation

Battery Storage

PV Arrays

Meters and

PMUs

Coupling Switch at

PCC

Vista Switches

Set Point Values

Control Commands

Monitoring Signals

SQL Database

SQL Database

OSIsoft PI System

OSIsoft PI System

SQL Database

SQL Database

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Ope

ratio

nal C

ontro

l Fun

ctio

ns

Disconnection:Capability for disconnection from the main grid due to

disturbances or outages

Re-synchronization and reconnection:Capability for resynchronization and reconnection to the

main grid after the main grid restorationPower quality control:

Providing required responses to PQ issues during ride-through transients and/or after stabilizing in islanded

modeProtection:

Applying basic protection schemes for detection and clearing internal and external faults

Generation dispatch:Adequate dispatch of all generation resources to maintain power and energy balances at all times

7Microgrid Controller FunctionalityThe BCM Master Controller will go through three stages of testing centered around the following operational control functions:

8Microgrid-Integrated Solar-Storage Technology

The MISST solution will have the following features:1. Be grid-connected2. Consist of solar PV plant and

energy storage3. Utilize smart inverters4. Be capable of operating in

conjunction with smart loads5. Enable demand response6. Incorporate solar and load

forecasting into decisions7. Be interoperable internally and

externally using standard protocols

Microgrid-Integrated Solar-Storage Technology (MISST) – will use smart inverters for solar PV/battery storage to achieve better economic, resiliency and reliability outcomes in the context of a microgrid.

9MISST MilestonesPerformance metrics are quantified for at least one year after deployment of MISST solution, lessons learned and scaling up methodologies, processes and considerations are documented and disseminated via conference presentations and online publication of technical report and paper.

Metric Definition (From Field Testing) Success Value Assessment Tool

Solar PV Power Level ≥ 0.75 MW Review by DOE or a third-party designated by DOEBESS Power Level ≥ 0.5 MW

Submitted technical paper from subtask efforts 1 Peer reviewSolar Frequency Control Deviation +/-0.5 Hz

A statistical method to confirm that success value has been

met with an acceptable level of certainty. (e.g. covering 2

standard deviations) 

Review by DOE or a third-party designated by DOE

Solar Voltage Control Deviation +/- 5%BESS Frequency Control Deviation +/-0.5 Hz

BESS Voltage Control Deviation +/- 5%Solar Forecasting Accuracy (Daily MAPE) +/- 10%

Increased solar penetration level in the microgrid attributable MISST 20% to 35%

BESS Cycle Efficiency >= 90%Hours of BESS Operating at Full Capacity 4 hours

BESS Internal Energy Loss (in a fully charged state) <= 5%