solar canada 2015 technical transformation breakout stream · pdf filesolar canada 2015...

Presented by:

Solar Canada 2015 Technical Transformation Breakout Stream

Smart Inverters and System Benefits11:30am-12:45pm, December 8th, Room 204

Moderator:

Andrew Swingler, Associate Professor, University of Prince Edward Island

Speakers:

Roland Bründlinger, Senior Engineer, Austrian Institute of Technology

Tom Key, Technical Executive, Electric Power Research Institute

Eric Tate, Product Manager – Grid Tie Inverters, Eaton

Advanced smart inverter and DER functions

Requirements in latest European Grid Codes

and future trends

Roland Bründlinger

IEA-PVPS Task 14

AIT Austrian Institute of Technology

Solar Canada 2015 Conference, December 7th – 8th, 2015

Metro Toronto Convention Centre, Toronto, Ontario, Canada

Contents

Overview of today’s Grid connection

requirements for DER in Europe

Advanced functional requirements for DER in

European codes

Summary & recommendations

33

Contents




European codes


44

As of today there is still no formal EU wide directive on DER grid interconnection

Country specific grid codes, standards, guidelines, laws

Different legal and administrative levels

Fundamental differences between the countries

Issues for manufacturers and project developers

Specific product settings for each country/market

Complex and time consuming certification schemes

Increased costs and reduced competiveness

Critical issues for power system operation

Lack of coordination and compatibility

Risk of losing system security during wide-scale events due to undefined behaviour of DER (example 50.2 Hz issue)

Framework for DER interconnection in Europe

Country specific grid codes and standards

512/10/2015

Current requirements for advanced grid support in Europe

DER connected to MV distribution grids

612/10/2015

2008: DE

P/Q, P(f), remote

P, LVRT, FRR…2008: FR

P/Q, LVRT

>5MW2009/13: AT P/Q, P(f), LVRT...

2015: AT Q(U), extended Q,

P(U)

2011/13: IT

P/Q, P(f), Q(U),

remote P L/HVRT…

2010/14: ES

P/Q, P(f),

LVRT

>2/10MW

2007/13: DK

P/Q, P(f),

LVRT…

Current requirements for advanced grid support in Europe

DER connected to LV distribution grids

712/10/2015

2011/12: DE

P/Q, P(f), remote P,

…

2013: FR

Var. over-f trip

2013: AT P/Q, P(f),…

2015: AT Q(U),

extended Q, P(U)

2012: IT - P/Q, P(f),

Q(U), remote P, LVRT…

2014: IT – specific

requirements for ESS

2012/14: DK

P/Q, P(f), …

Selected European Country Requirements – LV Connection

Country Europe

(≤16 A)

Germany Italy Austria France Spain Europe

(≤16 A)

Europe

(>16 A)

Function 2007 2011 2012 2013 2013 11/14 2013 2014

P at low f No Yes (all) Yes (all) Yes No No Yes Yes

P(f) No Yes (all) Yes (all) Yes Yes* No Yes Yes

Q/cosφ No >3.68kVA >3 kVA >3.68kVA No No Yes Yes

Q(U) No No >6 kVA Yes* No No Yes Yes

P(U) No No Optional Yes* No No No Optional

Remote P No >100kW >3 kVA >100kW No No No Yes

Rem. trip No No Yes (all) No No No No Yes

LVRT No No >6 kVA No No No No Yes

HVRT No N/A No No No No No Yes

Reference EN 50438 2007

(superseded by

EN 50438

2013)

VDE AR N

4105: 2011

CEI 0-21:2014 *TOR D4:2015

(to be

published)

* ERDF-NOI-

RES_13E

Version 5 -

30/06/2013

RD 1699/2011

206007-1

IN:2013

EN 50438 2013 CLC/TS 50549-

1:2015

812/10/2015

Selected European Country Requirements – MV Connection

Country Germany Italy Austria France Spain Europe NC RfG

Function 2008 2012 2013 2013 2010 2014 2013

P at low f Yes Yes Yes >5MW No Yes Yes (ABCD)

P(f) Yes Yes Yes No >2/10MW Yes Yes (ABCD)

Q/cosφ Yes Yes Yes Yes >2/10MW Yes Yes (BCD)

Q(U) optional Yes Yes No No Yes Yes (BCD)

Remote P >100kW Yes >100kW No >2/10MW Yes Yes (BCD)

P(U) No Optional Yes* No No Optional No

Rem. trip optional Yes No No No Yes Yes (ABCD)

LVRT Yes Yes Yes >5MW >2MW Yes Yes (BCD)

HVRT No Yes No No No Yes No

Reference BDEW MV

Guideline (2008)

CEI 0-16:2014 *TOR D4:2015

(not yet

published)

Arrêté du 23 avril

2008

P.O.12.3:2006;

P.O.12.2:

RD1565:2010;

UNE 206007-2

IN:2014

CLC/TS 50549-2 Final Version

RfG 2013

910.12.2015

Contents




European codes


1010

Advanced grid support features of DER

Requirements in European codes

• On demand, schedule or characteristics

• cos(phi) = f(P)

• cos(phi) = f(U) (optional)Voltage support

• Reduction of active power at over frequency

• Active power feed-in at under frequencyFrequency support

• Temporary limitation of active power output at congestion in the grid

• Controlled on demand by grid operatorGrid management

• LVRT (Low Voltage Ride Through)

• Contribution to short-circuit current

Dynamic grid support


Reactive power capabilities

1310.12.2015

CLC/TS 50549-1:2015 Requirements for the connection of generators above 16 A per phase

Connection to LV grids


Reactive power: Operational requirements

CL

C/T

S 5

05

49

-1:2

01

5

Re

qu

ire

me

nts

fo

r th

e c

on

ne

ctio

n o

f g

en

era

tors

ab

ove

16

A p

er

ph

ase

Co

nn

ectio

n to

LV

grid

s


Reactive power control modes

Autonomous reactive power control modes

Q / cos = constant

Q / cos = f(U)

Q / cos = f(P)

Q priority

Coordinated control (with communication)

cos = remote setpoint

Selection criteria

Characteristics of the electric grid (impedance, angle...)

Grid losses

Available control and communications infrastructure


Reactive power control strategies: Q(U)

Example characteristics for Q respectively cosφ control

mode according to CLC/TS 50549-1:2015 for

Connection to the LV distribution system

CL

C/T

S 5

05

49

-1:2

01

5

Re

qu

ire

me

nts

fo

r th

e c

on

ne

ctio

n o

f g

en

era

tors

ab

ove

16

A p

er

ph

ase

Co

nn

ectio

n to

LV

grid

s




• cos(phi) = f(P)










Active power control/frequency control: Standard functions

Reduction of active power at over-frequency (Limited Frequency Sensitive Mode Overfrequency)

Source: ENTSO-E RfG 2015

Parameter Range Default setting

Threshold

frequency f1

50,2 Hz to 52 Hz 50,2 Hz

Droop 2 % to 12 % 2,4%

Intentional delay 0 s to 2 s 0 s

CL

C/T

S 5

05

49

-1:2

01

5

Re

qu

ire

me

nts

fo

r th

e c

on

ne

ctio

n o

f g

en

era

tors

ab

ove

16

A p

er

ph

ase

Co

nn

ectio

n to

LV

grid

s


Additional requirements for frequency support

Behavior at under-frequency

Some national codes (e.g. DE, IT, AT…) already require

continued operation down to underfrequency limit (typ.

47.5 Hz)

EU Network Code RfG will provide extensive requirements for

all generator types

Operating ranges (Hz/time)

Rate of change of frequency (ROCOF) immunity

CLC/TS 50549-1/2 also specifies Rate Of Change Of

Frequency (ROCOF) immunity requirement

>2.5 Hz/s

1912/10/2015

So

urc

e: E

NT

SO

-E R

fG 2

01

5




• cos(phi) = f(P)



• Active power feed-in at under frequency

Active power control







Grid management

Possibility for DSO to send setpoint values to generators

Reduce the active power output or change the cos(phi).

Guarantee grid stability in case of emergency situations or congestion

~

=

DSO

Control Centre

Control signals

(e.g. Power Limitation)

Grid State

Distribution Grid

TSO

Control Centre

Transmission Grid

Demand for

power limitation




• cos(phi) = f(P)







• HVRT (High Voltage Ride Through)




Dynamic grid support: Low/High Voltage Ride Through

Requirement 1 (LV+MV): Remain connected to grid

• CLC/TS 50549-1/2 HVRT requirements

• up to 120 % Un for 100 ms and

• up to 115 % Un for up to 1 s.

CL

C/T

S 5

05

49

-2:2

01

5

Re

qu

ire

me

nts

fo

r th

e c

on

ne

ctio

n o

f g

en

era

tors

ab

ove

16

A p

er

ph

ase

Co

nn

ectio

n to

MV

grid

s


Dynamic grid support: Low/High Voltage Ride Through

Requirement 2 (MV only): Provide reactive current

CL

C/T

S 5

05

49

-2:2

01

5

Re

qu

ire

me

nts

fo

r th

e c

on

ne

ctio

n o

f g

en

era

tors

ab

ove

16

A p

er

ph

ase

Co

nn

ectio

n to

MV

grid

s

Specific requirements for ESS

• Similar as for non-ESS type DER

• During charging and discharging modeVoltage support

• Reduction of active power generation at over frequency

• Activate charging storage at over frequency

• Activate discharging storage at under frequencyFrequency support



• Similar as for non-ESS type DERDynamic grid

support

Specific requirements for ESS - Operational concepts

Example: Storage system connected together with load

Defined in German ESS guideline:

Operational concepts:

Storage may not be charged when

active power is flowing in the direction of

the generator/ storage unit/consumer

(Z1 P+ > 0)

Storage unit may not be discharged

when active power is flowing into the

grid (Z1 P- > 0)

Active power limitation

Based on measurements of meter Z1/S1

2612/10/2015

FN

N G

uid

elin

e C

on

ne

ctin

g a

nd

op

era

tin

g s

tora

ge

un

its in

low

vo

lta

ge

ne

two

rks. 2

01

4

Boundary of property

PV System

Local loads

Specific requirements for ESS – Extended control functions

Voltage support

Defined in Italian Grid Interconnection Standard (CEI 0-21 V1:2014-12):

2710.12.2015

„rectangular“ capability (for plants > 6 kVA)

„triangular“ capability (for plants <= 6 kVA)

CE

I 0

-21

V1

:20

14

Re

fere

nce

te

ch

nic

al ru

les fo

r th

e c

on

ne

ctio

n

of a

ctive

an

d p

assiv

e u

se

rs to

th

e L

V e

lectr

ica

l u

tilit

ies

charging mode

discharging mode

Specific requirements for ESS – Extended control functions

Frequency support

Defined in Italian Grid Interconnection Standard (CEI 0-21 V1:2014-12):

2810.12.2015

CE

I 0

-21

V1

:20

14

Re

fere

nce

te

ch

nic

al ru

les fo

r th

e c

on

ne

ctio

n

of a

ctive

an

d p

assiv

e u

se

rs to

th

e L

V e

lectr

ica

l u

tilit

ies

Active charging from

grid @ over frequency

Active discharging to

grid @ under frequency

Contents




European codes


2929

Summary and recommendations from a

European Perspective 1/2

In Europe the role of DER – particularly PV and Wind has changed from a marginal technology to a

visible player in the electricity market

PV and grid parity further massive deployment in short and near term

In particular Germany and Italy act as show-case for high-penetration PV and provision of grid

support (voltage, frequency…) by decentralized PV and DER

Numerous countries already implemented advanced functionalities of DER in their national grid codes

and require DER to provide

Steady state and dynamic voltage support

• Q control…

Frequency control capabilities

• P control during frequency variations

On-demand response via remote control and communication

3012/10/2015

Summary and recommendations from a

European Perspective 2/2

Coordinated requirements needed for safe and reliable grid integration of high shares of DER

Harmonization of European national grid codes with upcoming Network Code RfG

Taking into account the technical capabilities of modern inverter based DER

Standardized procedures for DER certification and testing currently under development.

Providing access to these capabilities will be the key to improve system reliability and efficiency with

large share of DER

Appropriate grid codes and interconnection standards are the key to enable further deployment of

DER.

31

32

Many thanks for your attention!

Questions are welcome

Roland Bründlinger

AIT Austrian Institute of Technology

Giefinggasse 2, 1210 Wien, Austria

[email protected]

mailto:[email protected]

BACKUP SLIDES

3310.12.2015

European wide Standards and Technical Specifications

The EN 50438:2013 for “Micro Generators” ≤16 A

1st edition published in 2007 had no real impact due to

overruling national codes

Protection requirements

Power Quality specifications

Normative Annex with National Deviations for a large

number of European countries

Fundamentally revised edition published in December 2013

Advanced grid support functions: P(f), Q, etc.

Based on German and Italian requirements and principles

of upcoming Network Code RfG

Time period for implementation: 2016

National deviations remain however

3412/10/2015

European wide Standards and Technical Specifications

Upcoming CLC/TS 50549-1/2

For LV/MV connections >16 A

Comprehensive definition of advanced functions for

generators (including static converters and rotating

generators)

Based on the principles of the Network Code RfG network

code

Technical Specification

provide technical guidance for the connection of

generating plants which can be operated in parallel with a

public distribution network.

technical reference in connection agreements between

DNOs and electricity producers.

3512/10/2015

Contents



Future EU regulation for grid connection of DER

The European Network Code RfG


European codes


3636


European Network Codes

Situation in the European power system and

electricity market today

Increasing penetration of variable RES

Increased market-driven power flows

Delays in grid reinforcement

Declining inertia

Urgent need to establish European-wide rules

Close cooperation of system operators and

users during normal and disturbed

operating conditions

preserve or restore system security

3712/10/2015

So

urc

e: E

NT

SO

-E


The upcoming ENTSO-E Network Code on RfG

3812/10/2015

Transmission systems and their users need to be

considered comprehensively

• Generators

• DSOs

• Demand facilities

Power generation plays an important

role with their ability to provide ancillary

services for:

• system balancing / frequency control

• voltage control

• robustness against disturbances and stable operation

• system restoration after blackouts

Requirements for Grid Connection applicable to all

Generators (RfG)

• Establish legally binding EU wide harmonization of grid interconnection requirements

• Ensure system security with a growing share of RES and variable generation

• Avoid future regret and costly retrofits to ensure security of supply


Basic approach of the ENTSO-E RfG Network Code

Definition of capabilities from a systems perspective - largely independent of the technology

transmission grid area

connection level

generator capacity

3912/10/2015 https://www.entsoe.eu/major-projects/network-code-development/requirements-for-generators/

Type D

Type C

Type B

Type A

• Wide-scale network operation and stability

• Balancing services

• Stable and controllable dynamic response

• covering all operational network states

• Automated dynamic response and resilience to events

• System operator control

• Basic capabilities to withstand wide-scale critical events

• Limited automated response and control

Capacity

(Continental

Europe)

Voltage

level

> 75 MW ≥ 110 kV

> 50 MW < 110 kV

> 1 MW < 110 kV

> 0,8 kW < 110 kV

Framework for PV/DG interconnection in Europe

ENTSO-E RfG Network Code

4012/10/2015


Technical requirements addressed by the NC RfG 1/2

4112/10/2015

Addressed system aspect Requirement Type

A

Type B Type

C/D

Frequency stability Operating frequency ranges X X X

RoCoF withstand capability X X X

Limited Frequency Sensitive Mode - Overfrequency X X X

Constant active power output regardless of changes in Frequency X X X

Limitation of power reduction at underfrequency X X X

Automatic connection X X X

Remote ON/OFF X X

Active power reduction remote control X

Additional requirements related to frequency control X

Provision of synthetic inertia X


Technical requirements addressed by the NC RfG 2/2

4212/10/2015

Addressed system aspect Requirement Type

A

Type B Type

C/D

Robustness of power

generating modules

Fault-ride-through X X

Post-fault active power recovery X X

System restoration Coordinated reconnection X X

General system

management

Control schemes and settings X X

Electrical protection and control schemes and settings X X

Priority ranking of protection and control X X

Information exchange X X

Additional requirements to monitoring X

Voltage stability Reactive power capability X X

Fast reacting reactive power injection X X

Additional requirements for reactive power capability and control modes X


Implementation of the NC RfG

Establishment of the RfG through EU regulations

Legally binding in each Member State from date of entry into force

Definitions in RfG leave wide room for variation/interpretation by the local TSOs/NRAs

2015: NC RfG adopted by Member States

Early 2016: Publication in the Official Journal of the European Union Entry into force

4312/10/2015

So

urc

e: E

NT

SO

-E

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

Tom KeySenior Technical Executive, EPRI

[email protected]

Expected Power System

Benefits of Smart Inverters


45© 2015 Electric Power Research Institute, Inc. All rights reserved.

Agenda

PV variability and the analysis

Aim to increase “hosting capacity”

System benefits in a “smart” inverter

Integration challenges

– Determine settings

– Communicate with

the grid (DMS)

– Develop planning tools

– Evolve standards


Realities of PV generation

1 2 3

4 5 6 7 8 9 10

11 12 13 14 15 16 17

18 19 20 21 22 23 24

25 26 27 28 29 30 31

Thu Fri SatSun Mon Tue Wed

December 2011: Tennessee 1MW PV System Power

Calendar profiles are 1-minute averages derived from 1-sec data


Categories for Daily Variability ConditionsApplied Sandia’s variability index (VI) with clearness index (CI) to classify days

Clear Sky POA Irradiance

Measured POA Irradiance



High

Moderate

MildOvercast

Clear

VI < 2

CI ≥ 0.5

VI < 2

CI ≤ 0.5

2 ≤ VI < 5

5 ≤ VI < 10

VI > 10


Categories for Daily Variability Conditions





High

Moderate

MildOvercast

Clear

VI < 2

CI ≥ 0.5

VI < 2

CI ≤ 0.5

2 ≤ VI < 5

5 ≤ VI < 10

VI > 10

Variability Conditions: AZ

Variability Conditions: NMVariability Conditions: NJ

Q2 2012 Q3 2012 Q4 2012 Q1 20130

20

40

60

80

100

Perc

en

tag

e o

f D

ays (

%)

Season

Variability Conditions: TN

Q2 2012 Q3 2012 Q4 2012 Q1 20130

20

40

60

80

100

Perc

en

tag

e o

f D

ays (

%)

Season

Q2 2012 Q3 2012 Q4 2012 Q1 20130

20

40

60

80

100

Perc

en

tag

e o

f D

ays (

%)

Season

Q2 2012 Q3 2012 Q4 2012 Q1 20130

20

40

60

80

100

Perc

en

tag

e o

f D

ays (

%)

Season

Using a clearness index (CI) and a variability index (VI) and to classify days


Aiming for Feeder Analysis using PV DataCircuit map showing locations of pole-mount systems in Rome, GA

SubstationSubstation

© Google – Map data © Google

= DPV Site= DPV Site

0.0 mi.0.0 mi. 0.5 mi.0.5 mi. 1.0 mi.1.0 mi.

1 km2 grid

MagicCarpet4 Rome May 2.wmv

MagicCarpet4 Rome May 2.wmv


Potential Grid Issues with PV

Voltage

• Overvoltage

• Voltage variations

Equipment Operation

• Feeder regulators,

• Load tap changers

• Switched capacitor banks

Demand/Energy

• “Masking” peak demand

• Unbalancing supply and demand

System Protection

• Relay desensitization, networks

• Breaker reduction of reach

• Unintentional islanding

Power Quality

• Harmonic generation

• Flicker worries

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

7 8 9 10 11 12 13 14 15 16 17 18 19P

ow

er (p

er-

unit)

Hour


Analysis combines PV scenarios with individual feeder characteristics

Baseline – No PV

PV Penetration 1

PV Penetration 2

PV Penetration 3

Beyond…

Increase Penetration Levels

Until a Violation Occurs

• voltage

• protection

• power quality

• thermal

PV

Systems

Process is

repeated

100’s of

times to

capture

possible

scenarios


How much PV can

the existing grid

host?

EPRI White Paper summarizing ~ 5

years of research on the Integration

of DER.

Search “EPRI and 3002004777”

What matters most?

• DER technology

• DER size and location

• Feeder construction and

operation


Example: Overvoltage related hosting

capacity

2500 cases shown

Each point = highest primary voltage

ANSI voltage limit

Ma

xim

um

Fe

ed

er

Vo

lta

ge

s (

pu)

Increasing penetration (kW)

Minimum Hosting Capacity

Maximum Hosting Capacity

Total PV:

540 kW

Total PV:

1173 kW

Voltage violation

No observable violations regardless of

size/location

Possible violations based upon size/location

Observable violations occur regardless of

size/location


Learning: Each Feeder has unique response

Impact

Below

Threshold

Impact

Depends

Impact

Above

Threshold

DER Size and Location Feeder Construction and Operation

EPRI supports “OpenDSS” a public

software for research and education


Spatial- and time-based feeder with PV demo

Search: “Youtube Epri Pv Penetration”

MagicCarpet_Voltage_Pepco_long version.avi

MagicCarpet_Voltage_Pepco_long version.avi


Smart Inverter Research

Technology:

Easing grid integration of distributed

generation and storage resources

Challenges:

Standardizing functions and

communications.

Confirming what these resources can

do and how to use them.

Getting the grid ready to manage and

apply in everyday operations.

EPRI’s Role:

Participate, lead and inform standards

Conduct demos to “learn by doing”

Work with members to connect DER

to distribution management (DMS)

and to grid operations

EPRI Journal Summer 2014


Inverter – Role in PV Plants

PV inverter converts DC energy from solar modules in to AC energy and

interface the PV system with electricity grid

Traditional Inverter

• Harvesting maximum power from PV array

• Matching plant output with grid voltage and frequency

• Providing unintentional islanding protection

DC Power AC Power


Summary of Benefits

Voltage

Management

Bulk

System

SupportComm. &

Interactivity

Provides benefits

beyond delivering PV

energy to the grid…

• Volt-Watt Control

• Fixed Power Factor

• Volt-VAR Control

• Voltage Ride-through

• Freq Ride-through

• Freq-Watt Control

• Configuration

• Coordination

• R/T Feedback


IEEE 1547 – 2003

DR shall not actively regulate the voltage at the PCC

DR shall cease to energize if frequency >60.5Hz

Tighter abnormal V/F trip limits and clearance times

IEEE 1547a - 2014

DR may actively participate to regulate the voltage by changes of real and reactive power

DR shall be permitted to provide modulated power output as a function of frequency

Much wider optional V & F trip limits and clearance times

Under mutual agreement between the EPS and DR operators, other static or dynamic frequency and clearing time trip settings shall be permitted.

Smart Inverters: Adjusting to the Times…

Straighforward… Unknown…

Voltage

Management

Bulk

System

Support

Comm. &

Interactivity


Theory: Generation Should Have Ride-

Through Capability

Source: EPRI, Common Functions for Smart

Inverters, Version 3, 3002002233, Feb 2014

Voltage

Management

Bulk

System

Support

Comm. &

Interactivity


Theory: A Simple Communications

Hierarchy

DMS

Sensors, Switches, Capacitors, Regulators

MDMS OMS

DERMS

SOLAR BATTERY PEV

Enterprise Integration

GIS

SCADA / Field Networks

Etc.

Applications

Communication

Networks

DER

Devices

(functions)

Voltage

Management

Bulk

System

Support

Comm. &

Interactivity


Theory: Inverter grid support makes

a big differencePV at Unity Power Factor PV with Volt/var Control

2500 cases shown

Each point = highest primary voltage

ANSI voltage limit

ANSI voltage limit


Ma

xim

um

Fe

ed

er

Vo

lta

ge

(pu)

Ma

xim

um

Fe

ed

er

Vo

lta

ge

s (

pu)


No observable voltage violations regardless of PV size/location

Possible voltage violations based upon PV size/location

Observable voltage violations occur regardless of size/location

Minimum Hosting CapacityMaximum Hosting Capacity

Minimum Hosting Capacity

Max Hosting Capacity

Voltage

Management

Bulk

System

Support

Comm. &

Interactivity


Reality: Fixed Power Factor

…Not So Simple!

A single setting won’t

work for all locations

and types of DER

Multiple locations on

the same feeder

change the result

Its not a simple

problem to determine

and update settings in

real time.

Substation

DER

Region A

Region B

Region C

Var control may not be

needed due to minimal

voltage rise

Var control most effective

due to high X/R

Var control not as effective

due to low X/R

DER

DER

Single DER

System and

Location

End of feeder

Voltage

Management

Bulk

System

Support

Comm. &

Interactivity


Reality: Customizing Volt-VAR Profiles

Performance Objective Feeder Characteristics

Inverter Sizing Load & Solar Profiles

Voltage

Management

Bulk

System

Support

Comm. &

Interactivity

VoltVarBad_offpeak_solar_3_inverter_export.mp4.avi





Moving from research methods to everyday

utility analysis tools

Get Data

(e.g. from in

CYME, Milsoft,

Synergee, DEW)

Apply Methods

Show Output

case by case look needed

Location √no impact

Location XPotential risk

Details on Streamlined Method: EPRI Report 3002003278

http://www.epri.com/abstracts/Pages/ProductAbstract.aspx?productId=000000003002003278


Substation Marker

*hosting capacity

*Initial analysis results from TVA/EPB study, results not

finalized

Sample from EPB serving Chattanooga, TN

System Hosting Capacity(~ 300 distribution feeders)

Substation-level

Hosting Capacity

Feeder-level

Hosting Capacity


Together…Shaping the Future of Electricity

Tom Key

[email protected]

Senior Technical Executive, EPRI

Thanks for

participating!



Smart Inverters -challenges from a manufacturer’s perspective

• Codes and standards

• Standards for Distributed Energy Resources (DER) were originally conceived for low power equipment and installations

• We are building MW scale inverters and deploying them in projects measured in 10’s or 100’s of MW

• The previous rational from a utility perspective was essentially: “if anything goes wrong, get out of the way and let us deal with it”

• (or “turn off your little science project and let the big boys handle it”).

• As renewables become a significant part of generation – This has to change!

• A number of the issues we are facing now in Solar – the wind power industry has already had to deal with years ago

• Without clear and consistent standards, it will be very difficult to deliver what the industry wants and needs


Let’s look at a few examples of Smart features

These are features already in use:

• Power Factor support

• Watt vs VAR prioritization

• Low Voltage and High Voltage Ride Through (LVRT

and HVRT)


Power Xpert™ Solar 1670kW InverterPower Factor Support

Power Factor Support:

• Inverter supports ± 0.91 PF at rated

power

• At 1670 kW, inverter is capable of

providing ± 760 kVAR

• Inverter apparent power is 1831 kVA


Power Factor Support - 20MW plant example

• 20MW solar plant

• Power Factor requirement: ± 0.95

@ Point of Interconnection (POI)

• The balance of plant has to be taken

into account

• Reactive losses estimated to be 1.7

MVAR inductive

• Inverters PF capability of ±0.91

provides adequate VAR support to

meet POI requirements

-15

-10

-5

0

5

10

15

0 5 10 15 20MVA

RMW

MVAR_Cap_Required MVAR_Ind_Required VAR Losses

Supplied MVAR_Ind Supplied MVAR_Cap


Power Xpert™ Solar InverterWatts vs VAR prioritization• Inverter VAR control has two modes of operation:

1. VAR mode: inverter follows VAR set-points

2. PF mode: inverter follows PF set-points

• Active (Watts) and Reactive (VARs) current can be prioritized based on grid requirements:

• P priority: Inverter processes up to full rated active power from solar array (1670kW)

• Q priority: Inverter processes the commanded set-point for VAR, even if it means that active power is

curtailed

• The mode of operation is set via a command given by the plant controller (Modbus/TCP)

• All the current changes and limits are calculated automatically, taking into consideration the plant

controller commands and real-time power values


1,500A

~ 2,600A

3,000A

Iq

IdPF=0.867

Maximum allowed Current = 3,000A

Power Xpert™ Solar InverterWatts vs VAR prioritization

1,240A

Rated current = 2,730A

3,000A

Iq

PF=0.91

Maximum allowed Current = 3,000A

• Assuming full power is available in the array and

inverter is producing 2,730A @ PF=1

• A VAR set-point of 1,500A is passed to inverter

• Inverter controls will limit reactive current production to

1,240A so that the 3,000A current limit is not exceeded

Case 1 = P priority Case 2 = Q priority

• Assuming full power is available in the array and

inverter is producing 2,730A @ PF=1

• A reactive current set-point of 1,500A is passed to

inverter

• Inverter controls automatically curtail active current

production to 2,600A, so that the commanded reactive

current is produced and the 3,000A current limit is not

exceeded


Low and High Voltage Ride Through (LVRT & HVRT)

In many cases now, utilities are

already requiring HVRT and LVRT for

large Solar installations


Q delivered (37.5kVAr/div)

P delivered (37.5kW/div)

V grid (300V/div)

I grid (450A/div)

-0 VA

Low Voltage Ride Through – what does the inverter do?


Project example: APS Solar - Hyder Project

15 MW AC project with

complete Eaton BOS and

controls solution:

• Inverters

• Transformers

• MV Switchgear

• SCADA

• Controls

• Commissioning

• 10 Years O&M


APS Solar - Hyder Project


APS Solar - Hyder Project

• The Eaton Power Systems Automation (PSA) Team deployed a distributed grid control system across 9 solar inverters (15MW) covering 150 acres

• Implementation included:

• VAR control

• Closed loop voltage control at the POI

• Utility set points

• Detailed metering, monitoring, and data historian

• Custom GUI and reporting

A “Smart” system involves more than just the Inverter!


APS Solar - Hyder Project Supervisory Controller Implementation


Power Xpert™ inverter installations


Smart Inverters – what can we take away?

• What makes an Inverter “Smart”?

• The ability to participate in Grid Support and Stability

• Who or what else needs to be smart?

• Standards organizations

• Control systems

• Developers & Integrators

• It’s time to “Get Smart”


Thank you for your attention.

www.eaton.com/solar

Presented by:

Solar Canada 2015 Technical Transformation Breakout Stream

Smart Inverters and System Benefits11:30am-12:45pm, December 8th, Room 204

Moderator:

Andrew Swingler, Associate Professor, University of Prince Edward Island

Speakers:

Roland Bründlinger, Senior Engineer, Austrian Institute of Technology

Tom Key, Technical Executive, Electric Power Research Institute

Eric Tate, Product Manager – Grid Tie Inverters, Eaton

solar canada 2015 technical transformation breakout stream · pdf filesolar canada 2015...

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