Risk Mitigation through Protection - Home - SAPVIA 10313:2012 & SANS (IEC) 62305:2010-12 SAPVIA - Risk Mitigation through Protection 12 ... Risk Mitigation through Protection 5.3 Down-conductor

© 2015 DEHN + SÖHNE / protected by ISO 16016

Risk Mitigation

through Protection

SAPVIA - Risk Mitigation through Protection 1


Risk Mitigation through Protection

Agenda

Damages to PV Systems

Standards and Norms

Lightning Protection Concepts

Questions & Answers

Video: Isolated Lightning Protection System




PV Modules Damage

Combiner Box Damage

Inverter Damage

Communication System Damage

Sensitive Equipment Damage (Trackers, Security Systems)

Damage Statistics




PV Modules Damage

source: Solarzentrum Oberland GmbH

Arcing/Short-circuiting of PV Modules due to lightning




PV Modules Damage

SAPVIA - Risk Mitigation through Protection

Broken glasses, Burned/Melted DC Cables and Combiner Box

Defective bypass diodes

5



Combiner Box Damage

source: R. Schüngel, Munich


Melted Combiner Boxes and DC Cables

due to Short-Circuit currents

Breakdown of sensitive and or monitoring

components inside Combiner Box

6



Inverter Damage


Internal component failure inside an Inverter (Central & String)

7



Communication System Damage

Holes in the Cable insulation

Data cables causing failure of Switches, PLC’s etc…




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


South Africa has on average 10 times more lightning density (strikes/km2)

9



Damage Statistics – Damages Costs

source: Bayerischer Versicherungsverband 2014

Costs of Damages (2005-2014)

Evaluation Bayerischer Versicherungsverband



Standards & Norms

SANS 10313: 2012

SANS (IEC) 62305: 2010-12

EN 62305: 2009-10 (VDE 0185-305: 2012)



Standards and Norms

SANS 10313:2012 & SANS (IEC) 62305:2010-12

12SAPVIA - Risk Mitigation through Protection


Standards and Norms

EN 62305: 2009-10 (VDE 0185-305: 2012)



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.



Standards and Norms

Reasons why a LPS is required by Owners/Insurers


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!


Standards and Norms

Frequency of the risk of a Lightning Strike in South Africa


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!


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.



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.



Standards and Norms


(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.


© 2015 DEHN + SÖHNE / protected by ISO 16016 SAPVIA - Risk Mitigation through Protection

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


(translation)

20


Standards and Norms

IEC 62305:2010-2012, Part 3

21

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.



Standards and Norms


(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.



Standards and Norms


(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.



Standards and Norms


(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.



…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“



Lightning Protection Concepts

PV Systems with NO external lightning protection

PV Systems with BONDED external lightning protection

PV Systems with ISOLATED lightning protection



LIGHTNING PROTECTION CONCEPTS

PV system with NO external lightning protection system


Type 1+2

Type 1+2

Type 1+2



PV system with NO external lightning protection system


Type 2

Type 2



PV system with BONDED external lightning protection system

`


Derated Type1+2

Type 1+2



PV system with BONDED external lightning protection system


Type 1+2



PV system with ISOLATED external lightning protection system


Type 2

Type 2



PV system with ISOLATED external lightning protection system


Type 2

© 2015 DEHN + SÖHNE / protected by ISO 16016 SAPVIA - Risk Mitigation through Protection

DEHNconcept

Risk Assessments

Detailed Design of LPS & Earthing Systems


Questions???


ALEXIS. W. BARWISE

Managing Director (B. Eng)

DEHN AFRICA (Pty) Ltd.

Tel. +27 11 704 1487

[email protected]

www.dehn-africa.com

34


PV system with

ISOLATED external LPS


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Risk Mitigation through Protection - Home - SAPVIA 10313:2012 & SANS (IEC) 62305:2010-12 SAPVIA - Risk Mitigation through Protection 12 ... Risk Mitigation through Protection 5.3 Down-conductor