© 2015 DEHN + SÖHNE / protected by ISO 16016
Risk Mitigation
through Protection
SAPVIA - Risk Mitigation through Protection 1
© 2015 DEHN + SÖHNE / protected by ISO 16016
Risk Mitigation through Protection
Agenda
Damages to PV Systems
Standards and Norms
Lightning Protection Concepts
Questions & Answers
Video: Isolated Lightning Protection System
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Damages to PV Systems
PV Modules Damage
Combiner Box Damage
Inverter Damage
Communication System Damage
Sensitive Equipment Damage (Trackers, Security Systems)
Damage Statistics
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Damages to PV Systems
PV Modules Damage
source: Solarzentrum Oberland GmbH
Arcing/Short-circuiting of PV Modules due to lightning
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Damages to PV Systems
PV Modules Damage
SAPVIA - Risk Mitigation through Protection
Broken glasses, Burned/Melted DC Cables and Combiner Box
Defective bypass diodes
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Damages to PV Systems
Combiner Box Damage
source: R. Schüngel, Munich
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Melted Combiner Boxes and DC Cables
due to Short-Circuit currents
Breakdown of sensitive and or monitoring
components inside Combiner Box
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Damages to PV Systems
Inverter Damage
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Internal component failure inside an Inverter (Central & String)
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Damages to PV Systems
Communication System Damage
Holes in the Cable insulation
Data cables causing failure of Switches, PLC’s etc…
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Damages to PV Systems
Damage Statistics – Comparison (Frequency of Occurence)
Causes of damage (2003-2013)
Evaluation Mannheimer Versicherung
Causes of damage (2005-2014)
Evaluation Bayerischer Versicherungsverband
source: Bayerischer Versicherungsverband 2014source: Mannheimer Versicherung 2014
SAPVIA - Risk Mitigation through Protection
South Africa has on average 10 times more lightning density (strikes/km2)
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Damages to PV Systems
Damage Statistics – Damages Costs
source: Bayerischer Versicherungsverband 2014
Costs of Damages (2005-2014)
Evaluation Bayerischer Versicherungsverband
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Standards & Norms
SANS 10313: 2012
SANS (IEC) 62305: 2010-12
EN 62305: 2009-10 (VDE 0185-305: 2012)
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Standards and Norms
SANS 10313:2012 & SANS (IEC) 62305:2010-12
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Standards and Norms
EN 62305: 2009-10 (VDE 0185-305: 2012)
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Standards and Norms
DIN EN 62305-3 suppl. 1 (VDE 0185-305-3 suppl. 1):2012-10
(translation)
The required class of LPS (I-IV) is determined by means of a risk analysis
according to DIN EN 62305-2 (VDE 0185-305-2). The class of LPS can
also be defined in consultation with the planner, owner and/or user.
The VdS guideline 2010 provides an overview of statutory requirements
and a possible assignment of the class of LPS for structures based on the
experience of property insurers.
If the protection goal (reduction of the risk below the value of the
tolerable risk) cannot be achieved by a lightning protection system
alone, further protection measures are required (e. g. protection against
the risk of touch and step voltages or LEMP protection according to IEC
62305.
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Standards and Norms
Reasons why a LPS is required by Owners/Insurers
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DETAIL DESCRIPTION
Investment (Capital) > R Millions/Billions
Life time of the plant and equipment > 20 years
Return on Investment (Business Model) Linked to kWh output
Downtime due to damaged components > Time (hrs/days)
Insurance Access payable with every claim > R 500 k
Insurance premium hikes due to claims TBD
Breakdown of equipment due to inherent effects > R xxx
Degradation of equipment and components > R xxx
Lightning and surge protection measures are essential!
© 2015 DEHN + SÖHNE / protected by ISO 16016
Standards and Norms
Frequency of the risk of a Lightning Strike in South Africa
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ITEM DETAIL
Output (MWp) 75
Modules > 600k
Area (km2) 3
Lightning Density (strikes/km2) 3.3
Total Direct Lightning (year) 9.9
Rain Season (months) 5 – 6
Total Strikes in Rain Season (months) 1.5 – 2
Total Cost of the Plant R 2 Bil
Total Loss as a result of Lightning
(year) without Protection
R 20 Mil
Lightning and surge protection measures are essential!
© 2015 DEHN + SÖHNE / protected by ISO 16016
Standards and Norms
DIN EN 62305-3, suppl. 5 (VDE 0185-305-3 suppl. 5):2009-10
(translation)
Regulatory requirements frequently call for lightning protection
measures for this type of structure to prevent fire and/or to protect
persons.
If possible, a lightning protection system should be preferred which is
not directly connected to the photovoltaic power supply system and
where adequate separation distances are kept.
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Standards and Norms
IEC 62305:2010-2012, Part 1
A lightning protection system consists of an external and internallightning protection system.
Functions of an external lightning protection system:
Interception of direct lightning strikes by means of an air-terminationsystem
Conducting the lightning current to earth by means of a downconductor
Distribution of the lightning current in the earth by means of anearth-termination system
Functions of an internal lightning protection system:
Prevention of dangerous sparking in the structure by establishingequipotential bonding or keeping a separation distance between thecomponents of the lightning protection system and other conductiveelements in the structure.
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Standards and Norms
DIN EN 62305-3 suppl. 5 (VDE 0185-305-3 suppl. 5):2009-10
(translation)
5.2 External lightning protection
Based on the DIN EN 62305-3 (VDE 0185-305-3) lightning protection
standard, roof-mounted photovoltaic power supply systems should be
protected against direct lightning strikes by means of isolated air-
termination systems, as far as practicable.
NOTE If a photovoltaic power supply system is newly installed
on a structure, the existing electrical installation may have
to be adapted.
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5.3 Down-conductor systems
5.3.1 General
NOTE 2 The installation of as many down-conductors as possible, at
equal spacing around the perimeter interconnected by ring conductors,
reduces the probability of dangerous sparking and facilitates the
protection of internal installations (see IEC 62305-4).
This condition is fulfilled in metal framework structures and in reinforced
concrete structures in which the interconnected steel is electrically
continuous.
Typical values of the preferred distance between down-conductors are
given in Table 4.
Standards and Norms
DIN EN 62305-3 suppl. 5 (VDE 0185-305-3 suppl. 5):2009-10
(translation)
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Standards and Norms
IEC 62305:2010-2012, Part 3
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5.4 Earth-termination system
5.4.1 General
When dealing with the dispersion of the lightning current (highfrequency behaviour) into the ground, whilst minimizing any potentiallydangerous overvoltages, the shape and dimensions of the earth-termination system are the important criteria.
From the viewpoint of lightning protection, a single integrated structureearth-termination system is preferable and is suitable for all purposesIn general, a low earthing resistance is recommended. Earth-terminationshall be bonded in accordance with the requirements of 6.2.
SAPVIA - Risk Mitigation through Protection
© 2015 DEHN + SÖHNE / protected by ISO 16016
Standards and Norms
DIN EN 62305-4 suppl. 1 (VDE 0185-305-4 suppl. 1):2012-10
(translation)
4.4 Lightning current distribution in a ground-mounted PV system
Depending on the relevant class of LPS, the type of earth-termination
system and the soil resistivity, SPDs with a lightning current discharge
capacity of a some kA are sufficient for ground-mounted PV systems.
The sample calculations are based on a mesh size of 20 m x 20 m. In
case of larger mesh sizes, it is to be expected that higher partial
lightning currents flow via the d.c. SPDs.
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Standards and Norms
DIN EN 62305-3 suppl. 5 (VDE 0185-305-3 suppl. 5):2009-10
(translation)
5.6 Selection of surge protective devices
5.6.2 Type 1 surge protective device, lightning current carrying capability
It is recommended to use Type 1 surge protective devices on the d.c.
side of photovoltaic power supply systems, if
an external lightning protection system is installed and
the required separation distance from elements of the
photovoltaic power supply system is not kept.
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Standards and Norms
DIN EN 62305-3 suppl. 5 (VDE 0185-305-3 suppl. 5):2009-10
(translation)
5.6 Selection of surge protective devices
5.6.1 General
Surge protective devices for the d.c. side must be chosen in such a way
that they enter a safe state even in case of a short-circuit without
presenting a risk of fire resulting from overload and arc formation.
The manufacturer of the surge protective devices provides evidence that
the switching device integrated in the surge protective device has the
switching capacity required for the conditions at the place of installation.
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© 2015 DEHN + SÖHNE / protected by ISO 16016
…enter a safe state even in case of a short-circuit without
presenting a risk of fire
with Short-Circuit Interruptwithout Short-Circuit Interrupt
Video “Disconnection with SCI“Video “Disconnection without SCI“
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© 2015 DEHN + SÖHNE / protected by ISO 16016
Lightning Protection Concepts
PV Systems with NO external lightning protection
PV Systems with BONDED external lightning protection
PV Systems with ISOLATED lightning protection
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© 2015 DEHN + SÖHNE / protected by ISO 16016
LIGHTNING PROTECTION CONCEPTS
PV system with NO external lightning protection system
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Type 1+2
Type 1+2
Type 1+2
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LIGHTNING PROTECTION CONCEPTS
PV system with NO external lightning protection system
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Type 2
Type 2
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LIGHTNING PROTECTION CONCEPTS
PV system with BONDED external lightning protection system
`
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Derated Type1+2
Type 1+2
© 2015 DEHN + SÖHNE / protected by ISO 16016
LIGHTNING PROTECTION CONCEPTS
PV system with BONDED external lightning protection system
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Type 1+2
© 2015 DEHN + SÖHNE / protected by ISO 16016
LIGHTNING PROTECTION CONCEPTS
PV system with ISOLATED external lightning protection system
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Type 2
Type 2
© 2015 DEHN + SÖHNE / protected by ISO 16016
LIGHTNING PROTECTION CONCEPTS
PV system with ISOLATED external lightning protection system
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Type 2
© 2015 DEHN + SÖHNE / protected by ISO 16016 SAPVIA - Risk Mitigation through Protection
DEHNconcept
Risk Assessments
Detailed Design of LPS & Earthing Systems
© 2015 DEHN + SÖHNE / protected by ISO 16016
Questions???
SAPVIA - Risk Mitigation through Protection
ALEXIS. W. BARWISE
Managing Director (B. Eng)
DEHN AFRICA (Pty) Ltd.
Tel. +27 11 704 1487
www.dehn-africa.com
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