Surge and Lightning Protection in
PV systems
DEHN UK Limited
© 2012 DEHN + SÖHNE / protected by ISO 16016
Damage statistics for photovoltaic systems
Causes of damage (frequency of occurence)
Technical failure 6%
vermin bite 3%
Malevolence 3%
Storm 9%
Human failure 3%
Snow load 14%
Theft 2%
Fire 2%
Miscellaneous
32%
Lightning strikes and surges 26%
Source: Mannheimer Versicherung 2010
© 2012 DEHN + SÖHNE / protected by ISO 16016
Photovoltaik - Blitzschäden
30.09.10 / 4517e_f
Data from Met Office UK weather stations.
Most active days
Most active minutes
rank
date
strikes
rank
date/minute
strikes
1
28/06/2005
57873
1
19/06/2007 00:00
2
24/06/2005
44583
2
19/06/2007 17:11
3
19/06/2007
42839
3
19/06/2007 17:46
4
26/07/2006
33168
4
19/06/2007 17:14
5
22/07/2006
31726
5
19/06/2007 17:04
Most active hours
Most active seconds
rank
date/hour
strikes
rank
date/minute
strikes
1 19-06-2007 17:00-18:00
14696
1
04/09/2005 21:03
2 28-06-2005 16:00-17:00
12585
2
22/07/2006 12:48
3 19-06-2007 18:00-19:00
9165
3
28/06/2005 17:05
4 28-06-2005 15:00-16:00
5821
4
13/05/2007 12:02
5 28-06-2005 17:00-18:00
5667
5
24/06/2005 14:09
Most active bursts
rank
date start/duration
strikes
05-111 2008 08:15:40.987 0.881ms
19
28-082 2007 15:14:17.915 0.882ms
17
05-113 2008 07:48:42.329 0.681ms
16
05-114 2008 07:48:39.665 0.761ms
15
04-095 2005 20:16:32.652 0.511ms
14
© 2012 DEHN + SÖHNE / protected by ISO 16016
Robin Earl Dehn UK limited
340
335
328
322
313
36
36
33
32
30
The UK risk to a Southern England located PV farm
6 MW PV farm covering 15 Hectares
15 Hectares = 0.15 km2
From BS62305 flash density figure map
we have 0.9 strikes /km2/year
This equals 0.14 strikes per year so we
expect the PV farm to be struck at least
in 7.1 years !
© 2012 DEHN + SÖHNE / protected by ISO 16016
Damage to field based PV arrays
and simple protection measure
© 2012 DEHN + SÖHNE / protected by ISO 16016
Damaged inverter
© 2012 DEHN + SÖHNE / protected by ISO 16016
Photovoltaik - Blitzschäden
30.09.10 / S3525e_b
Galvanic coupling effect on a PV system from direct
lightning strikes (LPS fitted but no SPDs )
100 kA
GJB
Example ûE
100 kA · 1  = 100 kV
100 kV
230 / 400 V
SEB
100 kV
MEB
GJB = generator junction box
SEB = service entrance box
MEB = main earthing busbar
© 2012 DEHN + SÖHNE / protected by ISO 16016
1Ω
Photovoltaik - ÜS-Ursachen
30.09.10 / S1500e_e
Inductive coupling effect
(LPS fitted but no SPDs)
GJB
230 / 400 V
SEB
MEB
GJB = generator junction box
SEB = service entrance box
MEB = main earthing busbar
© 2012 DEHN + SÖHNE / protected by ISO 16016
Photovoltaik - ÜS-Ursachen
30.09.10 / S1500e_f
Inductive coupling of lightning currents into PV
modules depending on the distance from the module
Copper wire
PV module with
short-circuited output
terminals
Measurement of the
impulse current induced
© 2012 DEHN + SÖHNE / protected by ISO 16016
Distance variation
Impulse current generator
150 kA 10/350 µs
30.09.10 / S4216e_a
Inductive coupling of lightning currents into PV modules
depending on the distance from the module
(no direct electrical contact just the effect across the air gap)
kA
1.0
Distance: 0.5 m
Distance: 1 m
Distance: 2 m
0.8
0.6
induced impulse currents for
different distances
0.4
0.2
0.0
kA
-0.2
60
50
primarilyeingespeister
fed lightning current
Primäre
Blitzstrom
forunterschiedlichen
different distancesAbständen
bei
40
30
20
10
0
-10
0.349
0.570
0.791
1.012
1.233
1.454
1.675
1.896
ms
© 2012 DEHN + SÖHNE / protected by ISO 16016
Photovoltaik - ÜS-Ursachen
30.09.10 / S4216e_d
Faulty installation as proximity is too close
flashover and inductive effects
© 2012 DEHN + SÖHNE / protected by ISO 16016
Photovoltaik - Trennungsabstand HVI-Leitung
30.09.10 / 4014e_b
Faulty installation
Proximity onto the LPS
© 2012 DEHN + SÖHNE / protected by ISO 16016
Photovoltaik - Trennungsabstand HVI-Leitung
30.09.10 / 4014e_c
Examples of inductive coupling that can lead to
destructive results to the installation
© 2012 DEHN + SÖHNE / protected by ISO 16016
Lightning and surge protection for PV systems
Which SPD should be used - type 1 or type 2 ?
Is it possible to
maintain the separation
distance between the
lightning protection system
and the PV system?
yes
s
type 2 arrester
© 2012 DEHN + SÖHNE / protected by ISO 16016
Photovoltaik - ÜSS
30.09.10 / S5378e_a
With 1 - 3 questions leading to product selection
Q1
Type 1
or
Q2
Type 2
Central inverter (CI) and
combiner box (CB) for CI
or
String inverter
(SI)
or
Q3
DEHNcombo
DG M YPV..
© 2012 DEHN + SÖHNE / protected by ISO 16016
For string inverter CB
Ready to install
DG YPV..
DEHNcube
IP 20 - TS 35 rail
IP 65 – outdoor
15
10_2013_WW/CV
Spoilt for choice... –Type 2 fully featured SPD
DG M(E) YPV SCI
Type 2
Central inverter (CI) and combiner
box (CB) for CI
• Universal
150 V, 600 V, 1000 V, 1200 V
KEMA, UL approved
• Comfortable
Pluggable, version with remote signaling
contact, customized versions
• Tested according to EN 50539-11
ISCPV = 1000 A (2500 A)
• Tried and tested
More than 20 GW installed over the many
years, SMA, PowerOne, ABB, Sungrow,
Bonfiglioli, Fronius etc.
DG M YPV..
© 2012 DEHN + SÖHNE / protected by ISO 16016
16
10_2013_WW/CV
DEHNguard® M YPV SCI surge arrester
DC SPD must have rapid disconnect like true DC switch
without SCI
Video “Isolation without SCI“
© 2012 DEHN + SÖHNE / protected by ISO 16016
with SCI
Video “Isolation with SCI“
Photovoltaik - ÜSS
30.09.10 / S5846e_h
Type 2 surge protection d.c.
Which type of installation is used?
For distribution boards
Ready to install
DG
YPV SCI
UPV 765 V
In 16,3 A
© 2012 DEHN + SÖHNE / protected by ISO 16016
UPV 765 V
In 16,3 A
18
10_2013_WW/CV
With 1 - 3 questions leading to the product
Type 2
Concentrating on the essentials without
compromising safety
String inverter
(SI)
For string inverter CB
IP 20 - TS 35 rail
 SCI principle integrated in a compact
enclosure
 Nominal discharge current In
of 12.5 kA clearly exceeds the required
minimum value of 5 kA (prTS 50539-12)
 d.c. short-circuit current ISCPV
Use in (small and medium-sized) PV systems
with string inverters with ISCPV up to 200A = no
back up fuse
DG YPV..
© 2012 DEHN + SÖHNE / protected by ISO 16016
19
10_2013_WW/CV
Type 2 surge protection d.c.
Which type of installation is used?
For distribution boards
Ready to install
DG
YPV SCI
UPV 765 V
In 16,3 A
© 2012 DEHN + SÖHNE / protected by ISO 16016
DCU
YPV SCI
UPV 765 V
In 16,3 A
20
10_2013_WW/CV
With 1 - 3 questions to the product
Type 1
or
Type 2
Central inverter (CI) and
combiner box (CB) for CI
or
String inverter
(SI)
or
For string inverter CB
IP 20 - TS 35 rail
Ready to install
IP 65 – outdoor
DEHNcube
© 2012 DEHN + SÖHNE / protected by ISO 16016
21
10_2013_WW/CV
DEHNcube YPV SCI
Highlights
Ready-to-install SPD
 Fits perfectly for small inverters where an SPD could
not be integrated
 Ready-to-install, with connecting cable (accessories)
 Version for one or two MPP trackers
 Compact dimensions
can be flexibly installed near the inverter
solution for the protection of PV modules
 Simple and fast connection via fast terminals without
tools
 Approved SCI technology for maximum safety and
availability of the PV system
 Tested according to EN 50539-11  ISCPV = 1000 A
© 2012 DEHN + SÖHNE / protected by ISO 16016
22
10_2013_WW/CV
New DEHNcube the easy retro fit SPD for DC circuits
© 2012 DEHN + SÖHNE / protected by ISO 16016
23
Lightning and surge protection of PV systems - Which surge protective device
should be used - type 1 or type 2 ?
Direct connection to the
lightning protection
system
Is it possible to
maintain the separation
distance between the
lightning protection system
and the PV system?
no
yes
type 2 arrester
type 1 arrester
Metal roof
© 2012 DEHN + SÖHNE / protected by ISO 16016
Photovoltaik - ÜSS
30.09.10 / S5378e_b
With 1 - 3 questions to the product
Type 1 or
Type 2 = DS 109 the selection guide
•
Small
600 V, 1000 V and 1500 V d.c. with a width of only 4
modules
•
Cost-optimized
Approved and cost-optimized SCI technology – no
compromises on safety
•
Conform to standards
Type 1 + type 2 combined arrester with a discharge capacity
= Itotal 12.5kA (10/350) fulfills the latest standards
(prTS 50539-12:2013 and DIN EN 62305-3 Suppl. 5).
Tested to EN 50539-11  ISCPV=
DEHNcombo
•
1000A (2500A)
Fits always perfectly
For central and string inverter systems
© 2012 DEHN + SÖHNE / protected by ISO 16016
25
10_2013_WW/CV
Large scale PV
An example of a Protection Concept
for a Solar Power Plant.
© 2012 DEHN + SÖHNE / protected by ISO 16016
Examples_2012
24.05.12 / ESC_E_3
BS7671 amendment 1 Section 443.2.4 risk assessment
model for surge protection
The following are different consequential levels of protection:
(i) Consequences related to human life, e.g. safety services, medical equipment in
hospitals
(ii) Consequences related to public services, e.g. loss of public services, IT centres,
museums
(iii) Consequences to commercial or industry activity, e.g. hotels, banks, industries,
commercial markets, farms
(iv) Consequences to groups of individuals, e.g. large residential buildings, churches,
offices, schools
(v) Consequences to individuals, e.g. small or medium residential buildings, small
offices.
For levels of consequences (i) to (iii) protection against overvoltage shall be provided.
Note 2: There is no need to perform a risk assessment calculation for levels of
consequences (i) to (iii) because this calculation always leads to the result that
the protection is required.
Here the selection is clearer. We need to understand the application. If there are
consequences to (i), (ii) or (iii) just fit the SPDs for (iv) and (v) we now go to
calculations.
© 2012 DEHN + SÖHNE / protected by ISO 16016
Surge protection concept for a
solar power plant
PV modules
inverter-building
generator
junction
box
foundation earth electrode
e.g. DEHNventil M
Type DV M TNC 255 FM
© 2012 DEHN + SÖHNE / protected by ISO 16016
e.g. DEHNlimit
Type DLM PV 1000
Photovoltaik - Solarkraftwerke
e.g. DEHNguard M
Type DG M YPV SCI 1000 (FM)
30.09.10 / 4039e_c
SPDs for Datalines
Protection of Data Acquisition and Data Evaluation Devices
© 2012 DEHN + SÖHNE / protected by ISO 16016
Examples_2012
24.05.12 / ESC_E_3
System monitoring protection concept for datalines
data
acquisition
unit
© 2012 DEHN + SÖHNE / protected by ISO 16016
Photovoltaik - Datenerfassung
30.09.10 / S3532e_e
SPDs for perimeter CCTV and security systems
© 2012 DEHN + SÖHNE / protected by ISO 16016
Photovoltaik - Äußerer Blitzschutz
DEHN UNI Earthing Clamp
Part.-No. 540 251
© 2012 DEHN + SÖHNE / protected by ISO 16016
Part.-No. 540 250
IS PV Workshop Intersolar EU 2013 June 17 + 18, Neumarkt – GMM
6_2013/CV
In closing….
Thank you for your attention
Any questions?
© 2012 DEHN + SÖHNE / protected by ISO 16016