READ AND DELETE

For best results with this template, use PowerPoint 2003

Volt VAR OptimizationUse of Smart Inverters on High DG Penetration Circuits

Presenters: Andrija Sadikovic, Rustom Dessai

Jul 19, 2016

2

PG&E Company Overview

Service

Territory

Distribution

System

• Regulated investor-owned utility

• 5.5 million electric customers

• 70,000 sq. mile service territory

• Total Distributed Generation1 = 2,716 MW

• PG&E System Peak Load2 = 21,062 MW

(1) As of 6/14/2016 (2) From 7/13/2013

3

Agenda

1. Background on PG&E’s Volt VAR Optimization Smart

Grid Pilot Project

2. Exploration of how Smart Inverters can enhance VVO

3. VVO in support of DG hosting capacity

4

PG&E is 2 years into a 3 year VVO Pilot

• Objective - evaluate VVO’s ability to:

1. Enhance grid monitoring & control

2. Accommodate growing distributed generation

3. Improve grid efficiency and reduce energy demand

• Scope – lab test then field trial on 14 feeders

• Varying DG penetration (ranging from 0% – 35%: nameplate / peak)

• Four feeders with > 25%

• Preliminary* energy reduction results to date from 12 feeders:

• Summer/Fall 2015 Cumulative CVRf: 0.9

Summer 2015 Fall 2015 Winter

2015/2016

Spring 2016 Cumulative

0.2% 1.4% 1.6% 0.7% 1.1%

* Results will be refined through course of pilot as new data and analysis methods are introduced

5

• Original VVO feeder selection analysis done near end of 2013

• Observed significant increases in DG penetration on VVO feeders in short

span (<3 years) of pilot

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

A-1101 A-1102 A-1103 P-2101 P-2102 P-2103 B-1114 B-1115 B-1116 W-2104 W-2105 W-2106 D-1102 D-1104

VVO Feeder DG Penetration Increases

DG / Peak Load 2013 DG / Peak Load 2016

DG Penetration Increases on VVO Circuits: 2013-2016

6

No strategy

Disable VVO for any

reverse power seen at LTC or

regs

Ride-through reverse power only for regsset to co-gen

mode; Disable otherwise

Vendors not

allowed out

of test

phase

Caused

certain

systems to

trip regularly

around

midday

Works well

for PG&E’s

VVO circuits

so far

Reverse power VVO vendor strategy progression

Fe

ed

er

Head

MW

Lin

e R

eg

ula

tor

MW

0 MW

0 MW

7

Impact of Solar Generation on VVO M&V

Hour of Day

Rea

l P

ow

er

(MW

)

• When overlaying VVO on/off

days, significant duck curves

found from variations in solar

generation

• Revised regression algorithm to

include solar irradiance, as

impact was significant compared

to the amount of change trying to

be measured by VVO (1-2%)

• Resulted in 7 substation periods

having lower energy savings,

and 5 substation periods having

higher energy savings than

previous analysis

• One bank’s results went from

negative to positive energy

savings after including solar

irradiance effects

Real Power VVO On/Off Overlay

8

• Found existing voltage unbalance on feeders during summer severely

limited VVO functionality

• New visibility through frequent AMI voltage readings can help weed out

feeders that may have existing issues with voltage or voltage unbalance

• As part of the VVO pilot, PG&E enabled 15 min / hourly voltage reads

on 1 million meters to help inform future VVO feeder selection

Aug 25 Aug 26 Aug 27 Aug 28

VVO On

VVO Disables

VVO On

VVO Disables

126

120

114

Sept 29 Sept 30 Oct 1 Oct 2

126

120

114

VVO Off

VVO On

VVO Off

VVO On

Sum

mer

2015

Fall

2015

Lessons Learned: Feeder Screening

9

Agenda

1. Background on PG&E’s Volt Var Optimization Smart Grid

Pilot Project

2. Exploration of how Smart Inverters can enhance VVO

3. VVO in support of DG hosting capacity

10

Exploring value of Smart Inverters in support of VVO

• Modeling

• How can VVO control of Smart Inverters improve VVO performance?

• What value could VVO extract from “VARs at night”?

• Lab Testing (in progress)

• What “VVO friendly” power factor and Volt-VAR settings deliver safe

“no fight” conditions in the field

• Field Trial (starts in August 2016)

• Collaborate with 3rd party installers to:

Sign up customers to participate in the pilot and install Smart Inverters by

Q3 2016

Remote Smart Inverter control by adjusting Fixed Power Factor and Volt-

VAR settings in accordance to VVO use cases

11

Large DG

Dinuba Sub

Dinuba 1104 studied due to challenging voltage control conditions

Complex with concentrated DG

• > 100 circuit miles

• 5 line voltage regulators

• 23% DG penetration1

• Three large DGs: 2 x 1 MW, 1 x 0.7 MW

VVO Go Live in Jan 2016 drove

interest in predicting performance

(1) Measured as DG capacity / feeder peak load. At time study began, additional DG connection has raised penetration to 40% as of June 2016

Dinuba

12

Explored different control methods and DG levels

• Case 1: No VVO

• Case 2: VVO controls VRs and Caps, PV-DG operates at constant power

factor (typically unity)

• Case 3: VVO controls VRs, Caps, and DG smart inverter power factor

(either 0.95 leading, zero, 0.95 lagging)

Modeled Sunny through Cloudy Conditions

Cloud index 0

Cloud index 4

Cloud index 8

Modeled Existing to 4x DG Penetration

No DG

Existing

2x

3x

4x

6 AM – 9 PM

13

0%

2%

4%

6%

8%

10%

23% 47% 70% 94%

DG Penetration

Dinuba 1104: Quasi Time Series Analysis Results

Daytime (8 am – 6 pm)

VARs at Night

0%

2%

4%

6%

8%

10%

23% 45% 68% 91%

0%

3%

6%

9%

12%

15%

23% 47% 70% 94%

0%

3%

6%

9%

12%

15%

23% 45% 68% 91%

Energy Delivery Savings Line Loss Reduction

Case 2: Traditional VVO

Case 3: VVO plus SI p.f. control

Charts below show comparison of VVO savings metrics

Case 1 (No VVO) at varying DG penetration levels

Energy Reduction (MWh)

0.0

1.0

2.0

3.0

4.0

23% 47% 70% 94%

0.0

1.0

2.0

3.0

4.0

23% 45% 68% 91%

*Results should be deemed as preliminary regarding potential VVO benefits and specific to the feeder studied. It is recommended that further

analyses be conducted for a larger sample of feeders with varying topologies, voltage levels, customer densities, customer types, etc.

14

DG as Part of VVO – Technical Analysis Results

Case 3 (with control of SI) delivers better voltage control

15

Agenda

1. Background on PG&E’s Volt Var Optimization Smart Grid

Pilot Project

2. Exploration of how Smart Inverters can enhance VVO

3. VVO in support of DG hosting capacity

16

DG as Part of VVO – Technical Analysis Results

VVO (no control of SI) could increase the hosting capacity

17

Next Steps

VVO Pilot Smart Inverter Field Trial

• Adjust Smart Inverter p.f. and Volt-Var settings to evaluate impact

to VVO performance

Follow technology and

regulatory development to

automate use of Smart Inverters

• DERMS pilot in late 2016

• Follow ADMS / VVO / DERMS

technology developments

• California Distributed Resources

Plan – locational value of Smart

Inverters

GRID of

THINGS

18

READ AND DELETE

For best results with this template, use PowerPoint 2003

Volt VAR OptimizationUse of Smart Inverters on High DG Penetration Circuits

Andrija Sadikovic a7sw@pge.com

Rustom Dessai, PEr1dp@pge.com

19

Questions?