CLC/TS 50539-22:2010

SLOVENSKI STANDARD
01-november-2011
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Low-voltage surge protective devices - Surge protective devices for specific application
including d.c. -- Part 22: Selection and application principles - Wind turbine applications
Überspannungsschutzgeräte für Niederspannung - Überspannungsschutzgeräte für
besondere Anwendungen einschließlich Gleichspannung - Teil 22: Auswahl und
nwendungsgrundsätze - Überspannungsschutzgeräte für den Einsatz in
Windenergieanlagen
Parafoudres basse tension - Parafoudres pour applications spécifiques incluant le
courant continu -- Partie 22: Principes de choix et d’application - Parafoudres connectés
aux installations éolienne
Ta slovenski standard je istoveten z: CLC/TS 50539-22:2010
ICS:
27.180 Sistemi turbin na veter in Wind turbine systems and
drugi alternativni viri energije other alternative sources of
energy
29.120.50 9DURYDONHLQGUXJD Fuses and other overcurrent
PHGWRNRYQD]DãþLWD protection devices
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION
CLC/TS 50539-22
SPÉCIFICATION TECHNIQUE
May 2010
TECHNISCHE SPEZIFIKATION
ICS 29.120.50
English version
Low-voltage surge protective devices -
Surge protective devices for specific application including d.c. -
Part 22: Selection and application principles -
Wind turbine applications
Parafoudres basse tension -  Überspannungsschutzgeräte
Parafoudres pour applications spécifiques für Niederspannung -
incluant le courant continu - Überspannungsschutzgeräte
Partie 22: Principes de choix für besondere Anwendungen
et d’application - einschließlich Gleichspannung -
Parafoudres connectés aux installations Teil 22: Auswahl
éolienne und Anwendungsgrundsätze -
Überspannungsschutzgeräte
für den Einsatz in Windenergieanlagen

This Technical Specification was approved by CENELEC on 2009-10-30.

CENELEC members are required to announce the existence of this TS in the same way as for an EN and to
make the TS available promptly at national level in an appropriate form. It is permissible to keep conflicting
national standards in force.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels

© 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. CLC/TS 50539-22:2010 E

Foreword
This Technical Specification was prepared by the Technical Committee CENELEC TC 37A,
Low voltage surge protective devices.
It was circulated for voting in accordance with the Internal Regulations, Part 2, Subclause 11.3.3.3 and
was accepted as a CENELEC Technical Specification on 2009-10-30.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following date was fixed:
– latest date by which the existence of the CLC/TS

has to be announced at national level
(doa) 2010-04-30
__________
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Contents
Page
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 General . 6
5 Equipment to be protected . 6
6 Configuration of a typical wind turbine . 6
7 Protection of power circuits within a wind turbine . 8
7.1 Introduction . 8
7.2 Protection of the generator alternator excitation circuit . 8
7.3 Protection of the line side circuit of the generator . 9
7.4 Protection of control power lines .10
Annex A (informative) Typical values of vibration withstand of SPDs used in wind turbine
systems .13
Bibliography .14

Figures
Figures 1 – Example of typical wind turbine configuration .6
Figures 2 – Direct drive turbine .7
Figures 3 – Doubly fed turbine .7
Figures 4 – Doubly fed turbine – Protection of the generator with SPD1 .9
Figures 5 – Doubly fed turbine – Protection of the line side of the circuit . 10
Figures 6 – Doubly fed turbine – Protection of control power line . 11

Tables
Table 1 – Typical values for discharge current capabilities for T1 SPDs when LPL is 1 and the
system is a 3-phase system .8
Table 2 – Typical values for discharge current capabilities for T2 SPDs .8
Table 3 – Example of characteristics of the generator alternator excitation circuit and selected SPD .9
Table 4 – Example of characteristics of the line side circuit of the generator and selected SPD . 10
Table 5 – Example of technical characteristics of the SPDs used in the control power line
(230 V/400 V) . 11
Table 6 – Example of technical characteristics SPDs for auxiliary circuits, LPZ 0 – LPZ 1 . 12
Table 7 – Example of technical characteristics SPDs for auxiliary circuits, LPZ 1 – LPZ n . 12

1 Scope
This Technical Specification applies to surge protection of wind turbine generators and wind power
systems.
Normative references are made to generic standards for lightning protection, low-voltage systems and
high-voltage systems for machinery and installations and electromagnetic compatibility (EMC).
This Technical Specification defines requirements for selection and installation of surge protective
devices for the power circuits. Some special information about particular testing are also included
since there is not a current standard for testing surge protective devices for wind turbines.
2 Normative references
Void.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
LEMP protection measures system
LPMS
complete system of protection measures for internal systems against LEMP
[EN 62305-4:2006, Definition 3.9]
3.2
lightning current
i
current flowing at the point of strike
[EN 62305-1:2006, Definition 3.9]
3.3
lightning electromagnetic impulse
LEMP
electromagnetic effects of lightning current
NOTE It includes conducted surges as well as radiated impulse electromagnetic field effects.
[EN 62305-4:2006, Definition 3.4]
3.4
lightning protection level
LPL
number related to a set of lightning current parameter values relevant to the probability that the
associated maximum and minimum design values will not be exceeded in naturally occurring lightning
NOTE Lightning protection level is used to design protection measures according to the relevant set of lightning current
parameters.
[EN 62305-1:2006, Definition 3.38]
3.5
lightning protection system
LPS
complete system used to reduce physical damage due to lightning flashes to a structure
NOTE It consists of both external and internal lightning protection systems.
[EN 62305-1:2006, Definition 3.40]

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3.6
lightning protection zone
LPZ
zone where the lightning electromagnetic environment is defined
NOTE The zone boundaries of an LPZ are not necessarily physical boundaries (e.g. walls, floor and ceiling).
[EN 62305-1:2006, Definition 3.35]
3.7
lightning stroke
single discharge in a lightning flash to earth
[EN 62305-1:2006, Definition 3.4, mod.]
3.8
metal installations
metal items in the structure, which may form a path for lightning current, such as the nacelle bed plate,
elevator guide rails and wires, ladders, platforms and interconnected reinforcing steel
[EN 62305-3:2006, Definition 3.18, mod.]
3.9
natural component of LPS
conductive component installed not specifically for lightning protection which can be used in addition
to the LPS or in some cases could provide the function of one or more parts of the LPS
NOTE Examples of the use of this term include:
– natural air-termination;
– natural down-conductor;
– natural earthing electrode.
[EN 62305-3:2006, Definition 3.15]
3.10
surge
transient wave appearing as overvoltage and/or overcurrent caused by LEMP
NOTE Surges caused by LEMP can arise from (partial) lightning currents, from induction effects in installation loops and as
residual surges downstream of SPD.
[EN 62305-1:2006, Definition 3.34, mod.]
3.11
surge protective device
SPD
device that is intended to limit transient overvoltages and divert surge currents. It contains at least one
non-linear component
[EN 61643-11:2002, Definition 3.1]
3.12
voltage protection level
U
P
parameter that characterises the performance of the SPD in limiting the voltage across its terminals,
which is selected from a list of preferred values. This value shall be greater than the highest value of
the measured limiting voltages
[EN 61643-11:2002, Definition 3.15]

4 General
Due to the increased numbers of Wind Turbines that are used nowadays more data regarding losses
and damages due to lightning strikes are available. From these data it is clearly that surge protection
is an important issue and shall be carefully examined during the design and construction of a Wind
Farm. The purpose of this document is to outline the main protection issues to prevent damages due
to lightning focusing on the internal lightning protection system and more particularly to the selection
and application of surge protective devices that shall be used.
5 Equipment to be protected
The main electrical equipments that can be found, but not limited, in a wind turbine are the following:
• generator;
• frequency converter;
• driver control(s);
• wind turbine control panel(s);
• LV site of transformer including LV switchgear;
• HV site of transformer including HV switchgear;
• auxiliary circuits (i.e. warning lights).
6 Configuration of a typical wind turbine
Based on the basic equipment that a typical wind turbine is composed of, a guide for installation and
selection of power SPDs is presented. The SPDs in principle should be selected according to the LPZ
principle and to the required voltage protection level of the under protection equipment. The figure
below describes the main equipment that a wind turbine generator is composed of.
Blades Warning Lights
Meteo
Nacelle / Generator
Tower
Base / Transformer
Figures 1 – Example of typical wind turbine configuration

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There are two basic designs of wind turbines, which may require a different surge protection approach
due to their electrical wiring configuration. The first one is the direct drive turbine, where the generator
output is directly connected to the frequency converter and the second design is the doubly fed turbine
(some time called double fed), which the generator has two outputs, one directly connected to the LV
switchgear and a second output which is connected to the frequency converter. This difference
requires also a different surge protection approach. However the protection scheme for a double fed
wind turbine generator system is also applicable for a direct drive.
LP Z 0
LP Z 1
Transformer
Converter
Generator LP Z 2
A D
C C
D A
C C
Pitch Drive
LP Z 2
Control
Figures 2 – Direct drive turbine
LP Z 0
LP Z 1
Generator
Transformer
LP Z 2
D
A
Pitch Drive
C
C
D A
C C
Converter
LP Z 2
Control
Figures 3 – Doubly fed turbine

Shielding and bonding are described in EN 62305-3. The purpose of this
...