© 2015 Electric Power Research Institute, Inc. All rights reserved.

Matthew RylanderEPRI

April 20, 2015

Streamlined Method for Determining

Distribution System Hosting Capacity

2© 2015 Electric Power Research Institute, Inc. All rights reserved.

Overview

Streamlined Method to Analyze Feeder Hosting Capacity for Distributed Generation–Why do we need it?–How does it work?

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Why do we need a Streamlined Method? PV Growth

U.S. Annual PV Additions

Growth fueled by falling economics, Renewable Portfolio Standards (RPS), financing schemes, net energy metering,

greenhouse gas (GHG) emissions reduction initiatives

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Why do we need a Streamlined Method? Analysis

Feeders

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Why do we need a Streamlined Method? Analysis

Voltage

Protection

Loading

Control

Feeders Issues

Imp

act

Total DER Penetration

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Why do we need a Streamlined Method? Analysis

Feeders Issues Scenarios Hosting Capacity

Imp

act

Total DER Penetration

UncontrolledDER Deployment

Impact Threshold

Optimal DER Deployment

Impact Below

Threshold

Impact Depends

Impact Above

Threshold

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Why do we need a Streamlined Method? Analysis

Feeders Issues Scenarios Hosting Capacity

Feeders with Similar

Characteristics

Impact Below

Threshold

Impact Depends

Impact Above

Threshold

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Load Screens

0

0.5

1

1.5

2

2.5

3

3.5

J1 R1 R2 R3 R4 T1 T2 G1 G2 G3 P1 P2 P3 P4 P5 D1 D2 D3

MW

Feeder

Minimum Hosting Capacity15% of Maximum Load

Too Conservative

Why do we need a Streamlined Method? Screens

Not Conservative Enough

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What type of Streamlined Method is needed?

• Capture unique feeder-specific responsesGranular

• As distribution feeders changeRepeatable

• System-wide assessmentScalable

• Clear and open methods for analysisTransparent

• Validated techniquesProven

• Utilize readily available utility data and toolsAvailable

EPRI’s Streamlined Hosting Capacity

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Evolution of Streamlined Hosting Capacity

Streamlined Hosting Capacity– Analysis performed in the Utility’s

distribution software tool– Minutes compared to weeks– Entire system analyzed

Detailed Hosting Capacity

Correlation Assessment

Streamlined Hosting Capacity

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What does the Streamlined Method look like?

Interface with utility model in the utility platform to attain:– Voltage Profiles– Currents/Loading– Impedances– Topology

Streamlined Hosting Capacity currently performed external to commercial software

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How does the Streamlined Method work on a feeder?

Single System

Resistance from Source

SubstationH

ost

ing

Ca

pac

ity

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How does the Streamlined Method work on a feeder?

Multiple Systems and Topology

Resistance from Source

SubstationH

ost

ing

Ca

pac

ity

Must Account for Feeder Topology

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How does the Streamlined Method work on a feeder?

Distributed Systems

Resistance from Source

Substation

Ho

stin

g C

ap

acity

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Feeder-Level Hosting Capacity

Resistance from Source

Hos

ting

Cap

acity

Optimal PV Deployment

Hosting Capacity Range

Non-Optimal PV Deployment

Max HC

Min HC

Impact Below

Threshold

Impact Depends

Impact Above

Threshold

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What does Feeder-Level hosting capacity look like?

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Outcomes of the Streamlined Hosting Capacity Analysis

This is not a replacement for detailed studies but it does provide guidance to when detailed studies are necessary

Questions Answered– Where is the “optimal” location for DER?– How much aggregate DER can a feeder

host?– When my feeder changes, how is

hosting capacity impacted?– What is the aggregate level of DER that

can be accommodated at the substation level?

– What amount of DER can be accommodated across my entire system?

– What are the range of issues for accommodating DER across the entire distribution system?

=

Feeder Level

Feeder Level

Feeder Level

Substation Level

Overvoltage

ThermalLoading

RelayCoordination

VoltageFluctuations

RelayDesensitization

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Final Thoughts…

PV is comingNeed efficient methods to plan for it

Methods will continue to evolve– Consideration of existing distributed energy resources– Inclusion of other types of distributed energy resources– Advanced inverter capabilities

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Together…Shaping the Future of Electricity

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Minimum Hosting Capacity ComparisonMultiple Issues for One Feeder

Utility Class DER

Residential/Commercial DER

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Minimum Hosting Capacity ComparisonOne Issue for Multiple Feeders

Utility Class DER Residential/Commercial DER

Preliminary Findings

+ Effectively identifies when lower hosting capacity values are found

+ Close match at low hosting capacity

+ More conservative result at higher hosting capacity

+ Comparable results for all potential issues

+ Effective for small-scale (customer-based) and large-scale (utility-sized) systems

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What about Distributed Residential/Commercial PV?

Location from Substation

Cur

rent

D

istr

ibut

ion

Location from Substation

DE

R

Dis

trib

utio

n

Location from Substation

Impa

ct

0.5 MW

1.0 MW

1.5 MW

0.5 MW

1.0 MW

1.5 MWImpact Threshold

0.5 MW

1.0 MW

1.5 MW

Location from Substation

Hos

ting

Cap

acity

DER Center 2DER Center 1 DER Center 3

1.5 MW 1.5 MW

1.5 MW

1.5 MW

DER Center 2DER Center 1 DER Center 3

Notes+ The streamlined method is not a stochastic analysis but the impacts from different possible DER deployments on the feeder are incorporated under the thousands of analyzed DER distributions. + The impact is not typically linear. Only illustrated here for visualization purposes. + Impact threshold for each issue is adjustable.

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Every Potential Issue has a Hosting Capacity that also Depends on…

Location from Substation

Pow

er

Extreme Boundary of Possible DER Distribution Characteristics

Hosting Capacity

Hosting Capacity with Lateral Diversity

More Probable Boundary of Possible DER

Distribution Characteristics

Con

serv

ativ

e

Hosting Capacity Range

Opt

imis

tic

Rea

listic

Notes+ Extreme bounds only possible with large pockets of DER either at the feeder head or end. + Probable bounds incorporate randomness in DER location across feeder. + Lateral diversity indicates higher hosting capacity based on DER distributed across parallel laterals on the feeder.

No IssuesPotential Issues

Issues