Multi Functional PV Inverters

8/6/2019 Multi Functional PV Inverters

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Content

Characteristics of PV inverters

Growing number of PV

Grid Integration of PV

Multifunctional PV inverters

Summary and outlook

Quelle: www.diehlako.de

Renewable Energy Technologies


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Characteristics of PV inverters [1]

Grid interface, integrated

rotection and monitorin

Conversion efficiency

device

functional safety

Derating Analysis (thermal,

overload)

Power Quality & Grid interaction Emission & Immunity

MPP Tracking

Stady state & dynamic

Behavior during network

disturbances Behavior during irregular

charcteristics

Evaluation of compatibility

Thermal behavior



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Characteristics of PV inverters [2]

conversion of energy with high efficiency

this is the main performance indicator for grid tied inverters.

Maximum Power Point Tracking

Safet and rid interaction behavior durin rid disturbances

Generator Inverter Grid



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Behavior during voltage dips

0.5

1

e(pu)

ause y

Grid faults

Switchin of lar e loads e(p.u.)

-1

-0.5Volta

Characterization by

Volta

. . . . . . . .

Time (s)

1u)

Remaining voltagelevel (in %)

p.u.)

0.4

0.6

0.8

MS

voltage(

duration magnitude

(in ms)

Point-on-Wave Rem. voltageMSvalue(

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.40

.

Time (s)

Phasejumps

level

Zeit (s)

R



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voltage tolerance diagram

00 VDE 0126 1 1Inverter with high sensitivity (Nr. 4)

%)8090

VDE 0126-1-1Inv. No. 1Inv. No. 2Inv No 3olt

age

ip(%)

tu ota(%

506070 Inv. No. 3Inv. No. 4

Inv. No. 5Inv. No. 6

Inverter with averagesensitivity (Nr. 2)

during

Mamannvo

304050 Inv. No. 6

Inv. No. 7Inv. No. 8Inv. No. 9Ride Throu h

equ redisconnectionaccording tog

elevel

(e

102030

Inv. No. 10Inv. No. 11Inv. No. 12

inverter (Nr. 9)- -

Volt

Duration (ms)0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 3000

Inv. No. 13

Duration of voltag dip (ms)



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Installed PV-power in PVPS countries

7

)

Grid-connected

Off-grid

5

Power(G

3

stalledP

V

1

2In

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

Quelle: IEA PVPS Programme (2008), Report IEA-PVPS T1-17: 2008



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Primary energy resources of the future

Forecast of the german advisory council on global change

Annual need of primary energy

others

Solarthermal

ea

PV and Solarthermalpower plants

Nuclear

Coal

Oil



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Role of Photovoltaic [1]

Correlation between generation and demand (supplying peak load):

source: www.q-cells.com

close to the load demand in the LV distribution network



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Role of Photovoltaic [2]

GW

]

ndload[

30 GWp of installed PVneration

requirements to the grid

management.

G

Day of the week


, . ,


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behavior during grid faults and disturbances

tuat on to ay:

Enormous increase of distributed generation capacity in thes r u on ne wor s arge num er on ase o s a c nver ers

Interconnection standards require inverters to shut down or to

,

even during grid faults

Simultaneous lost of a large number of distributed generation in



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Integration of PV Inverters

U



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Grid connection requirements in Germany

Base: Transmission Code 2007 (TC 2007)

Generators at MV network oa : app y o me um vo age ne wor s

Generators must

Contribute to short circuit current

Provide reactive power during normal operation

Reduce the active power injection when frequency

increases

u cat on:

Quelle: Volker Wachenfeld, SMA



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Multifunctional inverters [1]

Grid stability

Power and frequency control

Active power

> Decrease of active power injection versus

increase of frequency

When a grid disturbance occurs

oversupp y o power

To avoid instabilitiesFrequency

Fault Ride Through - capability

> No disconnection during grid faults (e.g.

> Inject mainly active or reactive power to

stabilize the grid voltage during grid fault

Quelle: www.enercon.de



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Grid stability

Coordinated voltage control

110/30 kV

110 kV

30 kV

M2

CVCU

dynamic voltage control

> Integration in various different control

conce ts e. . coordinated , local or remote

DG1

DG4

DG5

DG6

DG1

voltage control)

DG2

DG3

M1M3

Active power

> Goal: grid voltage control (within required

levels)

> Generators must rovide reacitve ower

during normal operation

> Reasonable for larger generatorsRective

power


Power limit diagram of inverter with STATCOM characteristics


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Power Quality

Filtering/Compensation ofHarmonics

> Compensation of unwanted harmonics

> FACTS Functions: D namic Volta e

Restorer, STATCOM etc. www.boddingtonspowercontrols.com

Compensation of voltage

unbalance



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Summary [1]

Inverter as interface between generator and

utility are the core component of DER Grid interaction and safety of inverters are

crucial at high penetration of DER.

es s n a ora ory o s a e-o - e-ar

inverters have shown:

Si nificant deficites of inverter behavior when

grid disturbances occur


Quelle: www.diehlako.de


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Summary [2]

PV enables good correlation between

generation and load Integration of inverter into the grid

management at high penetration of PV

apa y o supp y curren a so ur ng gr

disturbances

interface devices also during grid

disturbances



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Outlook

Increasing penetration of DER also gives

more possibilites to provide grid

Modern power electronic devices enable

active power injection

Fault Ride-Through Dynamic grid support

Active voltage and reactive power control

Use of PV inverter as active filters

Only a stable grid enables an unlimited

expansion of renewable energies



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Thank you for your attention!

Christoph MayrRenewable energy technologies

Giefinggasse 2, A-1210 Vienna

E-mail: [email protected]


Multi Functional PV Inverters

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