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Implementation of the European Network Code on Requirements for Generators on the European national level

Authors:

Abstract

This paper introduces the concept and approach of the European Network Code on Requirements for Generators NC RfG (EU Commission regulation 2016/631). It provides an overview on the status and details of the implementation in the main national markets for PV in Europe. For specific, non-exhaustive requirements of the RfG which are relevant for grid connected PV, a detailed comparison of the current national specifications is given. The overview is complemented by a summary of the EN 50549-X series of standards setting the requirements for generating plants to be connected in parallel with distribution networks.
Implementation of the European
Network Code on Requirements for Generators
on the European national level
Current Status - Trends and Challenges
Roland Bründlinger
AIT Austrian Institute of Technology
Vienna, Austria
roland.bruendlinger@ait.ac.at
Gunter Arnold, Nils Schäfer
Fraunhofer IEE
Kassel, Germany
Thomas Schaupp
KACO New Energy GmbH
Neckarsulm, Germany
Giorgio Graditi, Giovanna Adinolfi
ENEA - Italian National Agency for New Technologies,
Energy and Sustainable Economic Development
Naples, Italy
AbstractThis paper introduces the concept and approach of
the European Network Code on Requirements for Generators
NC RfG (EU Commission regulation 2016/631). It provides an
overview on the status and details of the implementation in the
main national markets for PV in Europe. For specific, non-
exhaustive requirements of the RfG which are relevant for
grid connected PV, a detailed comparison of the current
national specifications is given. The overview is complemented
by a summary of the EN 50549-X series of standards setting
the requirements for generating plants to be connected in
parallel with distribution networks.
Keywords- European Network Code; Requirements for
Generators; Interconnection standards; Distributed Generators;
I. INTRODUCTION
The publication of the Commission Regulation (EU)
2016/631 [1] establishing a network code on requirements
for grid connection of generators ("NC RfG") will
fundamentally impact the landscape of European national
grid codes and standards governing the connection of
generation from RES as well as non-RES. The NC RfG
establishes a EU wide harmonization of grid interconnection
requirements aiming at ensuring and increasing the system
security with a growing share of variable RES as well as
boosting the market of generation technologies and increase
competitiveness across Europe.
According to its nature as European Regulation, the NC
RfG will be "binding in its entirety and directly applicable",
with the individual requirements being applied for new PV
systems from April 27, 2019, 3 years after publication. Until
this date, existing national specifications, codes, standards
and other documents have to be in-line with the NC RfG.
During the first two years of this period (until May
2018), national specifications have been reviewed, amended
or adapted to meet the provisions, including detailing of all
non-exhaustive requirements. As part of the national
implementation, also the capacity thresholds for the
generator types have been specified by the relevant national
authorities.
The remaining period until 2019 will allow for
notification of the documents with the European
Commission, which is mandatory step before publication on
the national level. On the other hand, manufacturers and
project developers as well as grid operators have to take the
necessary steps to ensure compliance of their products and
processes within this given period.
II. THE EU NC RFG
A. Overview
The requirements in the RfG are based on a proportional
approach according to the system relevance of the
generators: For small scale generation basic requirements to
ensure system stability are being applied, in order to limit
additional costs for the implementation. With increasing
capacity, generators have to take over extended
responsibilities for system stability and operation.
Furthermore, the RfG is aimed to balance European wide
harmonized settings as well as to take into account regional
specifics.
Generally, the requirements of the RfG will be applied
for new generators in order to ensure system security in a
changing environment, accommodate evolution in the
generation portfolio and eventually to reduce costs through
standardization.
The application for existing generators (retrofit) is
foreseen provided it is technically justifiable, the benefits
demonstrated by Cost Benefit Analysis and last but not least
approved by National Regulatory Authority.
B. Approach
1) Differentiation of generators by type
The RfG categorises Power Generating Facilities into 4
types, depending on the transmission grid region
(synchronous area), their generation capacity and voltage
level. Depending on their type, the generators will have to
meet basic up to extended requirements as explained in the
NC RfG FAQ [2]:
Type A generators (connection below 110 kV and
maximum capacity is 0.8 kW or more) shall meet stable
operation over extended frequency range with limited
automated response and minimal system operator
control required.
Type B (connection below 110 kV, and a capacity
above threshold A/B and below B/C) generators
provide higher resilience to operational events,
appropriate dynamic response and basic system
operator control.
Type C generators (connection below 110 kV, and a
capacity above the threshold B/C and below C/D) shall
provide a stable and highly controllable (real time)
dynamic response to provide balancing services to
ensure security of supply. The requirements cover all
operational network conditions and detailed
specification of the functions, controls and information
exchange to utilise these capabilities. They ensure real
time system response necessary to avoid, manage and
respond to system events.
Type D (connection at 110 kV or above, and a capacity
above the threshold C/D) requirements cover a wide
area of control and range of operation. They ensure
specific needs for high voltage networks and their
operation and stability over wide areas, allowing the use
of ancillary services from generation Europe wide.
The NC RfG gives only maximum thresholds for the
generator types for the different synchronous areas in
Europe (TABLE I. ). Within these maximum limits, the
individual capacity thresholds which will be applied on the
national level are to be defined by the national regulatory
authorities through a so called “determination of
significance” process.
TABLE I. MAXIMUM CAPACITY THRESHOLDS FOR TYPE B, C AND D
POWER GENERATING MODULES [1]
Limit for maximum capacity threshold from
which on a Power generating module is of
Synchronous Area
type B
type C
type D
Continental Europe
1 MW
50 MW
75 MW
Great Britain
1 MW
50 MW
75 MW
Nordic
1.5 MW
10 MW
30 MW
Ireland and
Northern Ireland
0.1 MW
5 MW
10 MW
Baltic
0.5 MW
10 MW
15 MW
2) Technology-neutral approach
The requirements in the RfG are provided following a
technology-neutral approach. Instead the capability
requirements distinguish depending on the type of generator
(synchronous or static converter based). Accordingly, three
categories of requirements are distinguished:
1. general requirements (applied regardless of the type of
connection),
2. specific requirements for synchronously connected
generators, and
3. specific requirements for non-synchronously connected
generators (so called Power Park Modules).
3) Overview of requirements
The requirements for grid connection outlined in the NC
RfG are based on the generator type (A, B, C and D) as well
as their category (Synchronous vs. non-synchronous
generating facilities).
An overview of the requirements and the system aspect
addressed by them, is given in TABLE II.
TABLE II. OVERVIEW OF SYSTEM ASPECTS AND REQUIREMENTS
ADDRESSED BY THE NC RFG
System
aspect
Requirement
Frequency
stability
Operating frequency ranges
RoCoF withstand capability
Limited Frequency Sensitive
Mode - Overfrequency
Constant active power output
regardless of changes in
Frequency
Limitation of power reduction at
underfrequency
Automatic connection
Remote ON/OFF
Active power reduction remote
control
Additional requirements related
to frequency control
Provision of synthetic inertia
Robustness
of power
generating
modules
Fault-ride-through
Post-fault active power recovery
System
restoration
Coordinated reconnection
General
system
management
Control schemes and settings
Electrical protection and control
schemes and settings
Priority ranking of protection and
control
Information exchange
Additional requirements to
monitoring
Voltage
stability
Reactive power capability
Fast reacting reactive power
injection
Additional requirements for
reactive power capability and
control modes
4) Exhaustive vs. non-exhaustive requirements in the
NC RfG
One of the fundamental principles of the NC RfG is to
balance European-wide system needs and local specifics.
For this purpose, only requirements relevant for European-
wide system stability are defined exhaustively (“exhaustive
requirements”). All others are defined as “non-exhaustive”,
meaning further specifications and details are to be defined
through national regulatory authorities [3].
In detail this means that:
Exhaustive Requirements define capabilities of
generators by function or principle and by specified
parameters. No further specifications are to be made on
national level.
Non-exhaustive Requirements only define basic
capabilities, without further specification of parameters
and/or settings. Instead the parameters and/or settings
must be detailed on the national level, mainly to take
into account national or regional system characteristics
to finally become “exhaustive”.
In addition, there are also “non-mandatory”
requirements, where it is subject of the national bodies to
introduce obligatory rules.
Only a minor part of the requirements is exhaustively
defined in the NC RfG, mainly related to frequency ranges,
frequency withstand capability and voltage ranges.
Most of the requirements laid down in the NC RfG can
be classified as non-exhaustive. In most cases, this relates to
the fact that similar requirements already exist in the
countries, but with different parameters and/or settings.
Typical examples are e.g. FRT, data exchange, etc.
5) “Emerging technologies” exempted from NC RfG’s
requirements
This exemption opened a possibility to manufacturers,
where development had been started based on pre-RfG
requirements, but product sales could not yet return the
investment of the Development.
It allowed to exempt these technologies from the
requirement of RfG based on the following conditions:
Small capacity (Type A generators only)
Commercially available in the respective EU member
country
Cumulative capacity of installed generators of
“emerging technologies” in a synchronous area shall be
below a certain threshold.
Manufacturers had to apply for emerging technologies
status until November 17, 2016 with the relevant National
Regulatory Authority. All applications for products to be
classified as “emerging technologies” which were granted
are small-scale CHP generating units based on the principle
of linear free piston sterling engine.
III. NATIONAL IMPLEMENTATION
With the publication of the NC RfG in April 2016, a
three-year phase has begun which at the end, will result in
the full application of the requirements from April 27, 2019.
The transition phase consists of two parts:
1. During the first two years, the relevant national
regulatory authorities have developed draft documents
to implement the NC on the national level. The
documents and specifications were developed through
open consultation processes inviting relevant
stakeholders. The main purpose of this process was
detailing the non-exhaustive requirements of the NC to
be set at national or even project-specific level. In
addition, the capacity thresholds for the generator types
were specified.
Following the consultation, the national regulatory
authorities approved the proposal for the requirements
and additional specifications to be applied for the
implementation of the NC RfG. On the national level,
these documents may be national laws or decrees,
technical specifications or standards as well as
TSO/DSO guidelines.
Upon completion, all documents are to be submitted to
the European Commission for notification before they
can be published.
2. The remaining period until April 2019 allows the
involved stakeholders (vendors, project developers and
network operators) to ensure full compliance with the
Network Code requirements and implement them in
their products and processes.
To monitor the implementation process, ENTSO-E
provides a website which contains updated information from
the individual countries and links to their national
implementation sites. In addition, a so called “Monitoring
file” is provided which contains an overview of the
implementation of each requirement on the national level.
A. Definition of thresholds for the generator types
The definition of the thresholds of which a generator is
of a certain type is the basis for the implementation of the
NC RfG requirements on the national level. During the
implementation process the National Regulatory Authorities
must define the capacity thresholds based on the local
conditions.
As the local situation, deployment of different
generation technologies and types, practises and
requirements in the countries differ significantly, also the
considerations to define the capacity thresholds vary widely.
The table below presents the current situation in selected
EU countries, based on the currently available documents.
In some cases, the definitions are already implemented on
the national legal level, in other cases the proposals are
currently undergoing notification with the European
Commission.
TABLE III. PROPOSALS FOR CAPACITY THRESHOLDS FOR TYPE B, C
AND D POWER GENERATING MODULES IN SELECTED EUROPEAN COUNTRIES
Country
Actual capacity threshold from which on a Power
generating module is of
type B
type C
type D
RfG definition for
Continental Europe
1 MW
(maximum)
50 MW
(maximum)
75 MW
(maximum)
Austria [6]
250 kW
35 MW
50 MW
Belgium [8]
1 MW
25 MW
75 MW
Germany [7]
135 kW
36 MW
45 MW
Denmark [12]
125 kW
3 MW
25 MW
France [13]
1 MW
18 MW
75 MW
The Netherlands
1 MW
50 MW
60 MW
Spain [15]
100 kW
5 MW
50 MW
Italy [14]
11,08 kW
6 MW
10 MW
RfG definition for
Great Britain
1 MW
50 MW
75 MW
United Kingdom
[21]
1 MW
10 MW
50 MW
RfG definition for
Ireland and
Northern Ireland
100 kW
5 MW
10 MW
Ireland [20]
100 kW
5 MW
10 MW
As seen in the table, particularly the A/B thresholds that
will be applied differ considerably: While e.g. the NC RfG
allows for up to 1 MW, central European countries and
Spain set the threshold in the 100 kW to 250 kW range.
France, Belgium and the Netherlands opted to stick with the
NC limit of 1 MW.
Great Britain and Ireland/Northern Ireland will follow
the maximum capacity thresholds as defined in the NC RfG.
The currently proposed A/B threshold of Italy can be
seen as “outlier” as it was basically derived from the current
thresholds defined by the current Italian standards. In detail,
the A/B threshold of 11.08 kW represents the value reported
in the CEI 0-21 [15] for the voltage disturbances immunity
(Low Voltage Ride Through curve) requirement.
For the type B/C thresholds which will result in
additional requirements, particularly related to the
integration into system control, a similar picture can be seen.
National proposals range from 3 MW up to 50 MW.
RfG establishes B/C generating modules have to assure
frequency and voltage stability. Italian standards introduce
these requirements in case of 10 MVA and higher power-
generating modules.
Overall, the diversity of the requirements clearly reflects
the large variation related to the significance of certain
generator capacity ranges in the EU countries.
B. Selected Non-exhaustive requirements
In the following subsections, national proposals for
selected non-exhaustive requirements are summarised. Since
these requirements may have an impact on the design,
dimensioning and selection of generators and components,
they are of high relevance for vendors as well as project
developers.
The following national proposals for selected non-
exhaustive NC RfG requirements are being presented here:
Rate Of Change Of Frequency (ROCOF) withstand
capability: NC RfG Art 13.1(b)
Limited Frequency Sensitive Mode Over frequency
(LFSM-O) NC RfG Art. 13.2 (a-g)
Reactive Power Ranges for Type B PPM NC RfG Art.
20.2 (a)
Fault Ride Through (FRT) NC RfG Art. 14.3 (a-b) and
Fast fault current injection for Type B PPM NC RfG
Art. 20.2 (b-c)
For the analysis and comparison, the focus is laid on
Type B Power Park Modules (PPM), as they will be of
major relevance from both, the market point of view and the
significance in terms of new generation capacity to be added
in the near future.
1) Rate Of Change Of Frequency (ROCOF) withstand
capability requirements
One of the main new specifications introduced with the
NC RfG is the requirement for generators to withstand
frequency variations. According to the NC, Article 13.1(b)
“a power-generating module shall be capable of staying
connected to the network and operate at rates of change of
frequency up to a value specified by the relevant TSO,
unless disconnection was triggered by rate-of-change-of-
frequency-type loss of mains protection. The relevant
system operator, in coordination with the relevant TSO,
shall specify this Rate-Of-Change-Of-Frequency-type loss
of mains protection.”
This requirement will be applied to all generators under
the NC RfG, independently of their capacity.
TABLE IV. shows the requirements which are proposed
in the individual countries, based on the current status of the
available documents.
TABLE IV. PROPOSALS FOR RATE OF CHANGE OF FREQUENCY
(ROCOF) WITHSTAND CAPABILITY IN SELECTED EUROPEAN COUNTRIES
Country
Rate Of Change Of Frequency (ROCOF)
withstand capability
Requirement and
(measurement period)
Applicable to
RfG definition for
Continental Europe
None
ABCD
Austria [22]
2 Hz/s
ABCD
Belgium [8]
2 Hz/s
ABCD
Germany [24]
2 Hz/s (500 ms)
ABCD
Denmark [12]
2 Hz/s (200 ms)
ABCD
France [26]
N/A
UK [29]
1 Hz/s (500 ms)
ABCD
Ireland [28]
1 Hz/s (500 ms)
ABCD
Netherlands [27]
2 Hz/s (500 ms)
ABCD
Spain [18]
2 Hz/s (500 ms)
ABCD
Italy [14]
2.5 Hz/s (100 ms)
ABCD
In summary, most of the continental European countries
opted for a minimum of 2 Hz/s measured over a period of
500 ms. In GB and Ireland, lower values will be required.
2) Limited Frequency Sensitive Mode Over frequency
(LFSM-O)
Related to overall system and frequency stability, the NC
RfG requires generators to reduce their output power if the
frequency exceeds a certain threshold (Limited Frequency
Sensitive Mode Overfrequency (LFSM-O)”). The
response characteristic has to be defined by the relevant
national TSO/authority through the following parameters:
- Frequency threshold in Hz
- P/f droop setting in %
In addition, the national authority may specify additional
requirements related to the delay and operational
characteristics.
This requirement will be applied to all generators under
the NC RfG, independently of their capacity.
TABLE V. shows the requirements which are proposed
in the individual countries, based on the current status of the
available documents.
TABLE V. PROPOSALS FOR LIMITED FREQUENCY SENSITIVE MODE
OVER FREQUENCY (LFSM-O) SETTINGS IN SELECTED EUROPEAN
COUNTRIES
Country
Limited Frequency Sensitive Mode Over
frequency (LFSM-O) [Art. 13-2 (a-g)]
Requirement
Droop
Threshold
Delay
RfG definition
2% to 12%
Austria [22]
5%
50.2 Hz
none
Belgium [8]
5%
50.2 Hz
none
Germany [24]
5%
50.2 Hz
none
Denmark [12]
CE: 5 % (SPG/PPM)
N: 4 % (SPG/PPM)
CE: 50.2 Hz
N: 50.2Hz
none
France [26]
5%
50.2 Hz
<2 s
UK [29]
10%
50.4 Hz
<2 s
Ireland [28]
4%
50.2 Hz
none
Netherlands [27]
5%
50.2 Hz
none
Spain [18]
5%
50.2 Hz
none
Italy [14], [15],
[16]
2.6%
50.2 Hz
none
Except Italy, all continental European countries will
apply a 5% droop (equal to a power reduction of 40%/Hz).
The frequency threshold, from which the LFSM-O will be
activated is uniformly set to 50.2 Hz except for the UK,
where the threshold is set at 50.4 Hz. For most of the
countries, these requirements have already been established
in current codes and standards.
3) Reactive Power capabilities
Related to voltage stability, the NC RfG defines
requirements for the reactive power capabilities of
generators. These capabilities have to be provided by all
generators from type B upwards upon specification from the
relevant TSO/national authority.
TABLE VI. shows the requirements which are proposed
in the individual countries, based on the current status of the
available documents.
As the detailed conditions and specifications in the
national proposals differ for the generator types (BCD) and
technologies (SPGM and PPM), the focus of the comparison
is laid on PPMs of type B.
TABLE VI. PROPOSALS FOR REACTIVE POWER CAPABILITIES FOR
TYPE B PPM IN SELECTED EUROPEAN COUNTRIES
Country
Reactive power capability for Type B PPM
Requirement
Reactive power range
Q/Pmax
Voltage range
RfG definition
none
none
Austria [22]
-0.411 to 0.411
0.875 to 1.1 p.u.
Belgium [8], [11]
0.33/0.33
0.9 to 1.1 p.u.
Germany [24]
cosφ 0.9 at Pmax
0.9 to 1.1 p.u.
Denmark [12]
0.33/0.33
0.9 to 1.05
France [26]
0.35/0.4
Not specified
UK [29]
cosφ 0.9 at Pmax
0.95 to 1.05 p.u.
Ireland [28]
-0.33 to 0.33
Not specified
Netherlands [27]
-0.4 to 0.35
0.9 to 1.1 p.u.
Spain [18]
-0.3 to 0.3
0.95 to 1.05 p.u.
Italy [14], [15],
[16]
-0.484 to 0.484 (LV)
-0.312 to 0.312 (MV, Wind)
-0.436 to 0.436 (MV, PV)
not specified
Related to the reactive power capabilities of type B
PPMs, the current proposals in the individual countries show
significant differences, particularly related to the reactive
power and voltage ranges. In most cases, these reflect the
currently existing practises to include (distributed)
generators in the local voltage management.
4) Fault Ride Through (FRT) and Fast fault current
injection
To ensure robustness of generators during disturbances
and faults, the NC RfG requires all generators of type B to
provide FRT capabilities. This also includes the provision of
fast fault current (symmetrical as well as unsymmetrical) at
the connection point during a voltage deviation. In addition,
the generator also needs to provide “post-fault active power
recovery”. The detailed specifications for FRT (given as
voltage-time profile at the connection point), fast fault
current injection as well as post-fault active power recovery
have to be provided by the relevant TSO.
The FRT requirement is given as lower limit of a
voltage-against-time profile of the voltage at the connection
point (Figure 1. ), where a generator must be capable to
remain connected to the grid. The shape of the profile is
given through four voltage/time parameters as indicated in
Figure 1. In detail, Uret is the retained voltage during a fault,
tclear is the instant when the fault has been cleared. Urec1/trec1,2
and Urec2/trec3 define lower limits during recovery of the
voltage after clearance of the fault.
Figure 1. Definition of FRT (Under voltage ride through) curve in the
NC RfG Figure 3 [1]
TABLE VII. shows the FRT specifications which are
proposed in the individual countries, based on the current
status of the available documents. As the detailed conditions
and specifications in the national proposals differ for the
generator types (BCD) and technologies (SPGM and PPM),
the focus of the comparison is laid on PPMs of type B.
TABLE VII. PROPOSALS FOR FAULT-RIDE-THROUGH CAPABILITY OF
POWER PARK MODULES OF TYPE B IN SELECTED EUROPEAN COUNTRIES
Country
FRT capability of Type B PPMs
Voltage parameters
Time parameters
Uret
Uclear
Urec1
Urec2
tclear
trec1
trec2
trec3
RfG definition
(range)
0.05
to
0.15
Uret to
0,15
Uclear
0.85
0.14
to
0.25
tclear
trec1
1.5 to
3.0
Austria [22]
0.05
0.05
0.05
0.85
0.15
0.15
0.15
1.5
Belgium [8]
0.15
0.15
0.15
0.85
0.20
0.20
0.20
1.5
Germany [24]
0.15
0.15
0.15
0.85
0.15
0.15
0.15
3.0
Denmark [12]
0.15
0.15
0.15
0.9
0.25
0.25
0.25
1.5
France [26]
0.05
0.05
0.05
0.85
0.15
0.15
0.15
1.5
UK [29]
0.10
0.10
0.10
0.85
0.14
0.14
0.14
2.2
Ireland [28]
0.15
0.15
0.15
0.85
0.25
0.25
0.25
2.9
NL [27]
0.05
0.05
0.05
0.85
0.25
0.25
0.25
3.0
Spain [18]
0.05
0.05
0.05
0.85
0.20
0.20
0.20
1.5
Italy [14],
[15], [16]
0.05
0.15
0.15
0.85
0.20
0.20
0.20
1.5
For FRT, the national requirements vary in the range
which is given in the NC RfG. Major differences are to be
noted for the recovery of the voltage after the clearance of
the fault, where the requirements vary from 1.5 to 3.0 s.
Besides FRT, also the details for the provision of fast
fault current have to be defined in the national requirements.
TABLE VIII. shows the specifications which are proposed
in the individual countries, based on the current status of the
available documents. As the detailed conditions and
specifications in the national proposals differ for the
generator types (BCD) and technologies (SPGM and PPM),
the focus of the comparison is laid on PPMs of type B.
TABLE VIII. PROPOSALS FOR FAST FAULT CURRENT INJECTION
CAPABILITY OF TYPE B PPMS IN SELECTED EUROPEAN COUNTRIES
Country
Fast fault current injection capability of Type B
PPMs
FFCI
RfG definition
On request of RSO/TSO
Austria [22]
Yes, 2 ≤ k ≤ 6
Belgium [8], [11]
Yes, reference to EN 50549-2 [32], 0<k<6
Germany [24]
Yes, 2 ≤ k ≤ 6
Denmark [12]
Yes, k=2
France [26]
Yes, reference to EN 50549-2 [32], 0<k<6
UK [29]
Yes, no parameters specified
Ireland [28]
Yes, no parameters specified
NL [27]
Yes, 2 ≤ k ≤ 10
Spain [18]
Yes, 2 ≤ k ≤ 6
Italy [14], [15], [16]
Yes
Related to the fast fault current injection capability, the
NC RfG only provides a basic definition. The detailed
implementation has to be specified on the national level.
Accordingly, the current documents also show a broad
variety, particularly related to the level of detail. While in
some countries, detailed specifications for the
implementation are provided, others only provide a basic
definition.
IV. EUROPEAN STANDARDISATION ACTIVITIES
A. Overview - CENELEC TC8X activities
Besides the national codes and specifications, also the
related European standards were reviewed and adapted to be
compatible with the provisions of the NC RfG.
For this purpose, the relevant CENELEC CLC/TC8X
(System aspects of electrical energy supply) WG3
(Requirements for connection of generators to distribution
networks) together with ENTSO-E has taken the necessary
decisions to update the following documents:
- EN 50438 [30] (Requirements for micro-generating
plants to be connected in parallel with public low-
voltage distribution networks) will be discontinued and
the non-overlapping requirements are to be merged into
EN 50549.
- EN 50549-1 [31]: Requirements for generating plants to
be connected in parallel with distribution networks -
Part 1: Connection to a LV distribution network
Generating plants up to and including Type B (formerly
CLC/TS 50549-1:2015 Requirements for generating
plants to be connected in parallel with distribution
networks - Part 1: Connection to a LV distribution
network above 16 A) has been revised and will be
published as EN with new title.
- EN 50549-2 [32]: Requirements for generating plants to
be connected in parallel with distribution networks -
Part 2: Connection to a MV distribution network
Generating plants up to and including Type B (formerly
CLC/TS 50549-2:2015 Requirements for generating
plants to be connected in parallel with distribution
networks - Part 2: Connection to a MV distribution
network) has been revised and will be published as EN
with new title.
- EN 50549-10 (Requirements for generating plants to be
connected in parallel with distribution networks -Part
10: Tests demonstrating compliance of units) is
currently under development and expected to be voted
in early 2019.
B. New revision to EN 50549 series of European
Standards
The new EN 50549 series of standards has a close
relationship with the NC RfG and at the same time reflects
the current technical market needs. The latter is of high
relevance for product vendors, since the requirements given
in the NC RfG typically do not provide sufficient detail to
implement a certain function in a product. As such, the EN
50549 goes beyond the scope of RfG, including definitions
for all capabilities of generators for operation in parallel to
distribution grids.
The EN 50549 will be applicable for type A and B
generating modules, thus representing the mass market for
small and medium scale power generators, where
standardized requirements and compliance verification are
of high relevance for vendors, system integrators, project
developers as well as the distribution system operators.
In addition, the EN 50549 also intends to “to serve as a
technical reference for the definition of national
requirements where the RfG European Network Code
requirements allow flexible implementation”. However, as
the NC RfG does not foresee the support of harmonized
standards, support for EN 50549 will depend upon the
national implementation of NC RfG.
Following the positive vote received from the European
National Committees in July 2018, the final publication of
the EN 50549-1/2 is expected for October 2018.
V. CONCLUSION
The implementation of the European Network Code
Requirements for Generators on the European national level
has started an extensive discussion process among all
involved stakeholders and authorities, as it deeply impacts
existing national legal, technical and regulatory framework
for the grid connection and operation of power generation.
As most of the requirements in the NC RfG are “non-
exhaustive”, they are to be detailed and specified on the
national level, organised by the National Regulatory
Authorities and relevant TSOs. Through public consultation
processes involving relevant stakeholders, the “non-
exhaustive requirements” as well as the capacity thresholds,
which are used to classify a generator to be of a certain
“type” were specified.
As of September 2018, most of the national requirements
have already been detailed and submitted to the European
Commission as part of the mandatory notification process.
However, a significant part of the work still has to be done
until the final application of the requirements from April 27,
2019.
ACKNOWLEDGMENT
The participation of Austria within IEA-PVPS Task 14
is funded in the frame of the IEA Research Cooperation
program by the Austrian Ministry for Transport, Innovation
and Technology under the “HD-PV” project, contract No.
FFG 848120.
The participation of Germany within IEA-PVPS Task 14
is funded in the frame of the IEA Research Cooperation
program by the German Federal Ministry for Economic
Affairs and Energy under the HiPe-PV2 project, contract
No. FKZ 0325785.
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