EPRI & Sandia Microgrid Symposium Utility Microgrids: Integrations and Implementation Challenges

  Andrew A. Reid Research & Development Con Edison of New York, Inc.

Con Edison Electric Distribution System

As of 2015:• Covers 604 square miles• Est. Population of approx. 9 million • Distribution system provided electric service to

~ 3.4 million customers• 64 (N-2) & 19 (N-1) Networks• ~ 2,200 distribution feeders• Total Distribution Transformer Capacity

29,698 MVA• 87% of the capacity is underground• 13% of the capacity is overhead

• All-time record peak 13,322 MW on 7/19/2013

3

Electric Distribution System

CHP

DRDR

CHP

PV

PV PV

PVPV

PV

Animated illustration of network load changes over 24 hours of a peak day

Outstanding issues to consider with Community Microgrids– DG Utilization (Operations Standpoint)

• Location, location, location

• Incentivize the right operation profile

– Conductor Reliability & Grid Reinforcement

– DER Controls & Communications

– Cost/Benefit Analysis

– Protection and Analysis • Reverse power flow through network protectors

5

DER Output Profile

6

Hypothesis Active management of DER output to match system conditions may lead to more efficient use of DER

Real-time Hosting capacity

DER power output

System hosting capacity varies according to load conditions

Rather than limit DER capacity to trough threshold, or incur system

cost to accommodate DER, control DER output according to

system conditions

Hosting capacity @ trough

time

PVL Model OpenDSS translation

Hourly Annual Time Series Analysis

7

♦Ridgewood network – MESHED!♦ ~5800 load objects

♦To control DER according to system conditions, entire circuit must be considered with annual generation and load time series profiles

Modeling approach

• When does DER output cause system issues? What are those impacts?

• How does active management strategy compare to traditional approaches?

• What enhancements to modeling tools are needed to analyze off-peak power flows? What types of data are required?

8

Key questions and use case

Example configuration: Carved-out network pocket in Ridgewood network

3 CHP scenarios

(1) Peak summer (905 kW)

(2) Peak winter (595 kW)

(3) No curtailment - Trough (340 kW)

• Network protectors open for majority of winter season– 75% to 85% (~91 days/ season = ~2180 hours total)

• In transition season, network protectors open mostly over night

9

9

Network Protector Interaction with 905kW

• Switch actions occur in same pattern for each season:– Open during night time hours with over production

– Close during the day when heat load subsides and/ or demand picks up

10

10

Network Protector Interaction with 905kW

11

Post Curtailment GenerationPre Curtailment Generation

DG Output Profile – Thermal Load Following CHP (905 kW) + PV (160 kW)

Natural Load Profile Load Profile with DG

12

DER Effect on Microgrid Load profile

• Lessons Learned – Annual time series data is important!

• Construction of load profiles and subsequent validation essential

– Pre-modeling of DER arrangements can offer significant benefits due to potentially vast differences in hosting capacity across neighboring nodes

– DER should have a positive effect on normal network operation regional specific incentives required

– Location, location, location

• Next Steps – Post island protection and short circuit analysis

13

Moving forward …

EPRI & Sandia Microgrid Symposium Utility Microgrids: Integrations and Implementation Challenges

  Andrew A. Reid Research & Development Con Edison of New York, Inc.