ji.
co
m
en
w
w
w
.n
eo
ƒ Standards
ƒ Requirements
ƒ Earth fault protection
er
Electrical Safety
of PV installation
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
1
ƒ PV Systems from tens of W to multi MW
ƒ Voltages from 12 V to 600 V and more
ƒ Earthed and unearthed array frames
en
ƒ Transformer and inverter isolation:
ƒ HF transformer
eo
ƒ 50 Hz Transformers
ƒ Transformerless
er
ƒ Earthed and unearthed arrays
ji.
co
m
Basics
w
w
w
ƒ General public
.n
ƒ Provide electrical safety for
ƒ Informed workers (e.g. electricans)
ƒ Emergeny workers
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
2
ji.
co
m
Standards
.n
eo
en
er
ƒ International (IEC) for installations
ƒ IEC 60364-7-712:2002-05
Electrical installations of buildings –
Part 7-712: Requirements for special installations or locations –
Solar photovoltaic (PV) power supply systems
ƒ Technical specifications IEC TS 62257-7-1:2006-12
Recommendations for small renewable energy and
hybrid systems for rural electrification –
Part 7-1: Generators – Photovoltaic arrays
ƒ Technical specifications IEC 62257-5:2005-07
Recommendations for small renewable energy and
hybrid systems for rural electrification –
Part 5: Protection against electrical hazards
w
w
w
ƒ International (IEC) for PV inverters
ƒ IEC 62109-1 Ed.1: IEC 62109-1 Safety of power converters
for use in photovoltaic power systems - Part 1: General requirements
ƒ IEC 62109-2 Ed.1: Safety of power converters for use
in photovoltaic power systems - Part 2: Particular requirements for inverters
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
3
ji.
co
m
Standards
en
er
ƒ USA
ƒ UL 1741:1999-05-07
Static inverters and charge controllers for use in photovoltaic power systems
ƒ IEEE Std 929-2000
Recommended Practice for Utility-interface of Photovoltaic Systems
ƒ NEC 690
Grid-connected Photovoltaic systems
w
w
w
.n
eo
ƒ Other documentations
ƒ IEA International energy agenca / www.iea.org
ƒ Report IEA PVPS T05-04:2001
PV System Installation and Grid-Interconnection
Guidlines in selected IEC countries
ƒ Report IEC-PVPS T05-05:2002
Grid-connected photovoltaic power systems:
Survey of inverter and related protection equipment
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
4
w
w
w
.n
eo
en
er
ji.
co
m
Definitions according to IEC 60364-7-712 / DIN VDE 0100-712
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
5
ji.
co
m
PV system concept
Zentralised inverter
w
w
w
.n
eo
en
er
String inverter
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
6
ji.
co
m
PV systems today
en
er
ƒ Small PV systems
ƒ Transformerless inverter
ƒ Application circuit earthed
ƒ Insulation monitoring
or residual current monitoring
w
w
w
.n
eo
ƒ Big PV systems
ƒ Transformerless inverters
ƒ Application circuit
medium voltage via transformer
ƒ Insulation monitoring
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
7
ji.
co
m
Possible PV System Configurations
ƒ Array circuit (DC side) unearthed
er
ƒ Inverter with transformer
w
w
w
.n
eo
en
ƒ Application circuit earthed
ƒ Array circuit (DC side) unearthed
ƒ Transformerless inverter
ƒ Application circuit earthed
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
8
ji.
co
m
Possible PV System Configurations
ƒ Array circuit (DC side) unearthed
er
ƒ Inverter with transformer
w
w
w
.n
eo
en
ƒ Application circuit unearthed
ƒ Array circuit (DC side) unearthed
ƒ Inverter with transformer
ƒ Application circuit unearthed
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
9
w
w
w
.n
eo
en
er
ji.
co
m
Possible System Configurations
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
10
disconnecting
means
Overcurrent
Overvoltage
eo
.n
w
w
w
documentation
Equipment
class II
emergency shutdown
and alarm
marking
wire selection
& installation
er
People
en
Safety
ji.
co
m
General philosophy
earth fault
protection
earthing
requirements
equipment
requirements
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
11
er
en
w
w
w
ƒ Class II insulation
for larger system
.n
eo
ƒ Unearthed
ƒ Isolated and Safe
ƒ First fault
ƒ no current but
then earthed
ƒ Earthed
ƒ Shock risk
ƒ First fault
ƒ Fault current
ƒ Shock risk same
ji.
co
m
Earthing arrangement of PV arrays
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
12
ji.
co
m
Possible earthing arrangements
Negative earthed
w
w
w
.n
eo
en
er
Non earthed
Centre tap earthed
Capacitively Coupled centre tap earth
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
13
ji.
co
m
Possible protective measures (add. to IEC 60364-4-41)
w
w
w
.n
eo
en
er
ƒ IEC 60364-7-712 / DIN VDE 0100-712
ƒ 712.312.2 Earthing of DC side is permitted if separation between AC and DC side
ƒ 712.411.1 Protection by SELV / PELV max. DC 120 V
ƒ 712.413.1 Protection by automatic disconnection
ƒ On AC side, the PV supply cable shall be connected to
the supply side of the protective device for automatic
disconnection of circuits supplying current-using equipment
ƒ PV system without separation between AC and the
DC side an RCD installed to provide fault protection
by automatic disconnection of supply shall be type B
ƒ Protection by us of class II or equivalent insulation
shoud preferable be adopted on the DC side
ƒ 712.522.8.3
PV string cables, PV array cables and PV DC main cables shall be selected and
erected so as to minimize the risk of earth faults and short circuits
ƒ 712.536.2.1.1
To allow maintenance of the PV inverter, means of isolating
PV inverter from the DC side and the AC side shall be provided.
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
14
ji.
co
m
Big PV system
w
w
w
.n
eo
en
er
Array circuit unearthed (IT system) with insulation monitoring
Sensivity (MΩ) ≈ 36 / A where A is the PV array area in m2
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
15
ji.
co
m
A-ISOMETER IRDH275 with coupling unit AGH150W
w
w
w
.n
eo
en
er
Array circuit unearthed (IT system) with insulation monitoring
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
16
ji.
co
m
A-ISOMETER IRDH275 in String
w
w
w
.n
eo
en
er
Array circuit unearthed (IT system) with insulation monitoring
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
17
ji.
co
m
Earth fault protection for earthed PV array / earthed
w
w
w
.n
eo
en
er
Inverter with separating transformer, array and application circuit earthed
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
18
ji.
co
m
Earth fault protection for transformerless inverters (SMA)
w
w
w
.n
eo
en
er
Transformerless inverter, application circuit earthed
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
19
ji.
co
m
en
er
Thank you
eo
ƒ Dipl.-Ing. W. Bender GmbH&Co.KG
Londorfer Straße 65
35305 Grünberg – Germany
w
w
w
.n
ƒ Telefon: +49-(0)6401/807-0
ƒ Fax:
+49-(0)6401/807-259
ƒ Email: info@bender-de.com
© Dipl.-Ing. W. Bender GmbH&Co.KG 35305 Grünberg Germany
www.bender-de.com Fxxx / 09.2005 Änderungen vorbehalten
20