---
_id: '24550'
abstract:
- lang: eng
text: "Efficiencies and energy yields of microinverters available on the market
during 2014‒2021 have been \r\nmeasured, compared, and ranked. Conversion efficiencies
as a function of load have been measured indoors with high \r\naccuracy and ranked
according to Euro- and CEC weightings. Energy yields have been measured outdoors
via \r\nidentical and calibrated crystalline silicon PV modules of 215 Wp (until
2020) and 360 Wp (starting 2021). Inverters \r\nwith two inputs have been fed
by two of those modules. DC input, AC power output and energy yield of each micro\x02inverter
have been recorded by individual calibrated electricity meters. CEC and EU efficiency
rankings have been \r\ncomputed and compared. To assess the influence of PV module
size, two extremes have been investigated: A rather \r\nsmall module with 215
Wp - as it has been used 10 years ago, and a brand-new module (2021) offering
360 Wp. Both \r\ntypes of modules contain 60 solar cells in series connection.
Appling the low-power modules, the challenge for the \r\ndifferent micro-inverters
has been during weak-light conditions, using the high-power modules, some inverters
\r\ntemporarily reach their power limits and yield is reduced. A method using
a reference configuration of inverter & \r\nmodule and a linear equation y = ax
+ b resulting in the actual yield, any module & inverter configuration can be
\r\ncharacterized by just the coefficients a and b."
author:
- first_name: Stefan
full_name: Krauter, Stefan
id: '28836'
last_name: Krauter
orcid: 0000-0002-3594-260X
- first_name: Jörg
full_name: Bendfeld, Jörg
id: '16148'
last_name: Bendfeld
citation:
ama: 'Krauter S, Bendfeld J. Module-Inverters (Microinverters): Influence of Module
Size on Conversion Efficiencies and Energy Yields. In: Proceedings of the 38th
European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC 2021).
; 2021:659-663. doi:10.4229/EUPVSEC20212021-4CO.3.4'
apa: 'Krauter, S., & Bendfeld, J. (2021). Module-Inverters (Microinverters):
Influence of Module Size on Conversion Efficiencies and Energy Yields. Proceedings
of the 38th European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC
2021), 659–663. https://doi.org/10.4229/EUPVSEC20212021-4CO.3.4'
bibtex: '@inproceedings{Krauter_Bendfeld_2021, title={Module-Inverters (Microinverters):
Influence of Module Size on Conversion Efficiencies and Energy Yields}, DOI={10.4229/EUPVSEC20212021-4CO.3.4},
booktitle={Proceedings of the 38th European Photovoltaic Solar Energy Conference
and Exhibition (EU PVSEC 2021)}, author={Krauter, Stefan and Bendfeld, Jörg},
year={2021}, pages={659–663} }'
chicago: 'Krauter, Stefan, and Jörg Bendfeld. “Module-Inverters (Microinverters):
Influence of Module Size on Conversion Efficiencies and Energy Yields.” In Proceedings
of the 38th European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC
2021), 659–63, 2021. https://doi.org/10.4229/EUPVSEC20212021-4CO.3.4.'
ieee: 'S. Krauter and J. Bendfeld, “Module-Inverters (Microinverters): Influence
of Module Size on Conversion Efficiencies and Energy Yields,” in Proceedings
of the 38th European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC
2021), 2021, pp. 659–663, doi: 10.4229/EUPVSEC20212021-4CO.3.4.'
mla: 'Krauter, Stefan, and Jörg Bendfeld. “Module-Inverters (Microinverters): Influence
of Module Size on Conversion Efficiencies and Energy Yields.” Proceedings of
the 38th European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC
2021), 2021, pp. 659–63, doi:10.4229/EUPVSEC20212021-4CO.3.4.'
short: 'S. Krauter, J. Bendfeld, in: Proceedings of the 38th European Photovoltaic
Solar Energy Conference and Exhibition (EU PVSEC 2021), 2021, pp. 659–663.'
conference:
end_date: 2021-09-10
name: 38th European Photovoltaic Solar Energy Conference and Exhibition (EUPVSEC
2021)
start_date: 2021-09-06
date_created: 2021-09-16T10:17:11Z
date_updated: 2022-01-06T13:22:03Z
ddc:
- '620'
department:
- _id: '53'
doi: 10.4229/EUPVSEC20212021-4CO.3.4
file:
- access_level: closed
content_type: application/pdf
creator: krauter
date_created: 2022-01-06T13:20:31Z
date_updated: 2022-01-06T13:20:31Z
file_id: '29175'
file_name: Krauter Bendfeld - Module size Microinverters - EUPVSEC 2021.pdf
file_size: 5413518
relation: main_file
success: 1
file_date_updated: 2022-01-06T13:20:31Z
has_accepted_license: '1'
keyword:
- AC-modules
- Microinverter
- Power Conditioning
- Efficiency
- Yield
- PV module size
- saturation
- performance
language:
- iso: eng
page: 659 - 663
publication: Proceedings of the 38th European Photovoltaic Solar Energy Conference
and Exhibition (EU PVSEC 2021)
publication_identifier:
isbn:
- 3-936338-78-7
publication_status: published
quality_controlled: '1'
status: public
title: 'Module-Inverters (Microinverters): Influence of Module Size on Conversion
Efficiencies and Energy Yields'
type: conference
user_id: '28836'
year: '2021'
...
---
_id: '18387'
abstract:
- lang: eng
text: " During comparative measurements of different PV microinverters, two yield
issues came up that could \r\nnot be explored via conventional efficiency measurements,
but do have a significant impact on electrical energy \r\nyield: First category
of issues are either sluggish or nervously acting maximum–power–point–tracking
devices, which \r\nlead to reduced energy yields. The other category of issues
is thermal: As a first explanation for observed reduced \r\nenergy yields, it
has been assumed that the conversion efficiency degrades at higher operating temperatures.
This \r\nmatter has been investigated in this article: A change in conversion
efficiency could not be observed for elevated \r\noperation temperatures up to
50°C, despite high-precision and repeated measurements. But it was found that
some \r\ninverters temporarily interrupted (or entirely stopped) operation after
long periods of running at high temperatures. \r\nAlso, a reduction in potential
maximum power output has been detected for those inverters. Summarizing: With
a \r\nhigh degree of certainty it can be stated that those reported yield losses
have been caused by the temporary shutdowns \r\nand power limitations of the inverters."
author:
- first_name: Stefan
full_name: Krauter, Stefan
id: '28836'
last_name: Krauter
orcid: 0000-0002-3594-260X
- first_name: Jörg
full_name: Bendfeld, Jörg
id: '16148'
last_name: Bendfeld
citation:
ama: 'Krauter S, Bendfeld J. Elevated Temperatures Affecting Efficiency, Overall
Performance and Energy Yield of PV Microinverters. In: Proceedings of the EU
PVSEC 2020 . ; 2020:1179-1180. doi:10.4229/EUPVSEC20202020-4AV.3.6'
apa: Krauter, S., & Bendfeld, J. (2020). Elevated Temperatures Affecting Efficiency,
Overall Performance and Energy Yield of PV Microinverters. Proceedings of the
EU PVSEC 2020 , 1179–1180. https://doi.org/10.4229/EUPVSEC20202020-4AV.3.6
bibtex: '@inproceedings{Krauter_Bendfeld_2020, title={Elevated Temperatures Affecting
Efficiency, Overall Performance and Energy Yield of PV Microinverters}, DOI={10.4229/EUPVSEC20202020-4AV.3.6},
booktitle={Proceedings of the EU PVSEC 2020 }, author={Krauter, Stefan and Bendfeld,
Jörg}, year={2020}, pages={1179–1180} }'
chicago: Krauter, Stefan, and Jörg Bendfeld. “Elevated Temperatures Affecting Efficiency,
Overall Performance and Energy Yield of PV Microinverters.” In Proceedings
of the EU PVSEC 2020 , 1179–80, 2020. https://doi.org/10.4229/EUPVSEC20202020-4AV.3.6.
ieee: 'S. Krauter and J. Bendfeld, “Elevated Temperatures Affecting Efficiency,
Overall Performance and Energy Yield of PV Microinverters,” in Proceedings
of the EU PVSEC 2020 , online, 2020, pp. 1179–1180, doi: 10.4229/EUPVSEC20202020-4AV.3.6.'
mla: Krauter, Stefan, and Jörg Bendfeld. “Elevated Temperatures Affecting Efficiency,
Overall Performance and Energy Yield of PV Microinverters.” Proceedings of
the EU PVSEC 2020 , 2020, pp. 1179–80, doi:10.4229/EUPVSEC20202020-4AV.3.6.
short: 'S. Krauter, J. Bendfeld, in: Proceedings of the EU PVSEC 2020 , 2020, pp.
1179–1180.'
conference:
end_date: 2020-09-11
location: online
name: EU PVSEC 2020, 37th EU Photovoltaik Solar Energy Conference
start_date: 2020-09-07
date_created: 2020-08-27T06:26:25Z
date_updated: 2022-01-06T12:32:47Z
ddc:
- '620'
department:
- _id: '53'
doi: 10.4229/EUPVSEC20202020-4AV.3.6
file:
- access_level: closed
content_type: application/pdf
creator: krauter
date_created: 2022-01-06T12:27:02Z
date_updated: 2022-01-06T12:27:02Z
file_id: '29171'
file_name: Krauter Bendfeld - Microinverters at elevated temperatures EUPVSEC 2020.pdf
file_size: 599660
relation: main_file
success: 1
file_date_updated: 2022-01-06T12:27:02Z
has_accepted_license: '1'
jel:
- Q42
keyword:
- AC-modules
- Microinverter
- Power Conditioning
- Thermal Performance
- Ventilation
- Stability
- Efficiency
- Yield
language:
- iso: eng
page: 1179 - 1180
publication: 'Proceedings of the EU PVSEC 2020 '
publication_identifier:
issn:
- 3-936338-73-6
publication_status: published
quality_controlled: '1'
status: public
title: Elevated Temperatures Affecting Efficiency, Overall Performance and Energy
Yield of PV Microinverters
type: conference
user_id: '28836'
year: '2020'
...
---
_id: '16899'
abstract:
- lang: eng
text: To compare efficiency and yield of many micro-inverters available on the world
market in 2014-2020, an in- and outdoor test laboratory at the University of Paderborn
has been set up. The inverters have been fed by identical and calibrated crystalline
silicon PV modules of 215 Wp. To monitor accurately DC input, AC power output
and energy yield, each of the micro-inverters has been equipped with a calibrated
electricity meter. For micro-inverters requiring control units for grid-feeding
that has been acquired also. The comparison covers efficiency-load characteristics
as well as electrical energy yields. Purchase costs vary considerably between
the models in comparison, sometimes inverter costs are higher than module costs,
particularly if an additional grid-connection or interface device is needed for
operation. The weighted conversion efficiency according to EU and CEC standards
has been measured and calculated. While some inverters have been optimized for
high irradiance levels, they ranked better at the CEC efficiency, others performed
very well also for low irradiance levels, thus ranking higher at in the EU-efficiency
tables. These results are deviating from the actual energy yield measurements,
which show a slightly different ranking. At one inverter, an accurate, but very
slow MPPT algorithm that barely could follow quickly changing irradiance levels
could be the reason for this effect. Another inverter switched off after operation
at high power output for a while. Apparently, some inverters are been optimized
to show excellent EU and CEC efficiency ratings. Two of the inverters featuring
two inputs did not show an exceptional performance at the EU- and CEC-ratings,
but they achieved top ranks at the AC energy yield for the first years. For the
customer, the AC yield is a major performance indicator of any microinverter and
should be included in the datasheet.
author:
- first_name: Stefan
full_name: Krauter, Stefan
id: '28836'
last_name: Krauter
orcid: 0000-0002-3594-260X
- first_name: Jörg
full_name: Bendfeld, Jörg
id: '16148'
last_name: Bendfeld
citation:
ama: 'Krauter S, Bendfeld J. Comparison of Microinverters: Update on Rankings of
Conversion Efficiencies and Energy Yields. In: Proceedings of the 47th IEEE
Photovoltaic Specialists Conference (PVSC 47) JUNE 15 - AUGUST 21, 2020 VIRTUAL
MEETING. IEEE; 2020:1429-1432. doi:10.1109/PVSC45281.2020.9300953'
apa: 'Krauter, S., & Bendfeld, J. (2020). Comparison of Microinverters: Update
on Rankings of Conversion Efficiencies and Energy Yields. Proceedings of the
47th IEEE Photovoltaic Specialists Conference (PVSC 47) JUNE 15 - AUGUST 21, 2020
VIRTUAL MEETING, 1429–1432. https://doi.org/10.1109/PVSC45281.2020.9300953'
bibtex: '@inproceedings{Krauter_Bendfeld_2020, place={online}, title={Comparison
of Microinverters: Update on Rankings of Conversion Efficiencies and Energy Yields},
DOI={10.1109/PVSC45281.2020.9300953},
booktitle={Proceedings of the 47th IEEE Photovoltaic Specialists Conference (PVSC
47) JUNE 15 - AUGUST 21, 2020 VIRTUAL MEETING}, publisher={IEEE}, author={Krauter,
Stefan and Bendfeld, Jörg}, year={2020}, pages={1429–1432} }'
chicago: 'Krauter, Stefan, and Jörg Bendfeld. “Comparison of Microinverters: Update
on Rankings of Conversion Efficiencies and Energy Yields.” In Proceedings of
the 47th IEEE Photovoltaic Specialists Conference (PVSC 47) JUNE 15 - AUGUST 21,
2020 VIRTUAL MEETING, 1429–32. online: IEEE, 2020. https://doi.org/10.1109/PVSC45281.2020.9300953.'
ieee: 'S. Krauter and J. Bendfeld, “Comparison of Microinverters: Update on Rankings
of Conversion Efficiencies and Energy Yields,” in Proceedings of the 47th IEEE
Photovoltaic Specialists Conference (PVSC 47) JUNE 15 - AUGUST 21, 2020 VIRTUAL
MEETING, VIRTUAL MEETING, 2020, pp. 1429–1432, doi: 10.1109/PVSC45281.2020.9300953.'
mla: 'Krauter, Stefan, and Jörg Bendfeld. “Comparison of Microinverters: Update
on Rankings of Conversion Efficiencies and Energy Yields.” Proceedings of the
47th IEEE Photovoltaic Specialists Conference (PVSC 47) JUNE 15 - AUGUST 21, 2020
VIRTUAL MEETING, IEEE, 2020, pp. 1429–32, doi:10.1109/PVSC45281.2020.9300953.'
short: 'S. Krauter, J. Bendfeld, in: Proceedings of the 47th IEEE Photovoltaic Specialists
Conference (PVSC 47) JUNE 15 - AUGUST 21, 2020 VIRTUAL MEETING, IEEE, online,
2020, pp. 1429–1432.'
conference:
end_date: 2020-08-21
location: VIRTUAL MEETING
name: 47th IEEE Photovoltaic Specialists Conference (PVSC 47)
start_date: 2020-06-15
date_created: 2020-04-29T05:31:12Z
date_updated: 2022-01-07T10:10:43Z
department:
- _id: '53'
doi: 10.1109/PVSC45281.2020.9300953
keyword:
- yield
- AC
- micro-inverter
- MPPT
- CEC rating
- EU efficiency
- Photovoltaic
- Solar
language:
- iso: eng
main_file_link:
- url: https://ieeexplore.ieee.org/document/9300953
page: 1429-1432
place: online
publication: Proceedings of the 47th IEEE Photovoltaic Specialists Conference (PVSC
47) JUNE 15 - AUGUST 21, 2020 VIRTUAL MEETING
publication_identifier:
issn:
- ' 0160-8371'
publication_status: published
publisher: IEEE
quality_controlled: '1'
status: public
title: 'Comparison of Microinverters: Update on Rankings of Conversion Efficiencies
and Energy Yields'
type: conference
user_id: '28836'
year: '2020'
...
---
_id: '9760'
abstract:
- lang: eng
text: Self-optimizing systems are able to adapt their behavior autonomously according
to their current self-determined objectives. Unforeseen influences could lead
to dependability-critical behavior of the system. Methods are required which secure
self-optimizing systems during operation. These methods to increase the dependability
of the system should already be taken into consideration in the design process.
This paper presents a guideline for the dependability-oriented design of self-optimizing
systems, which integrates established classical methods like failure mode and
effects analysis as well as methods based on self-optimization. On the one hand
self-optimization is used to increase the dependability of the system by integrating
objectives like safety, availability, and reliability to the objectives of the
system. On the other hand methods are required to ensure the self-optimization
itself. As basis for this guideline serves the principle solution of the system.
The six phases of the guideline extend the design process and lead to an enhanced
principle solution. Additionally, the guideline illustrates phases to implement
and validate the self-optimizing system. The proposed guideline is applied to
an innovative rail-bound vehicle, called RailCab, which is equipped with self-optimizing
function modules.
author:
- first_name: Christoph
full_name: Sondermann-Wölke, Christoph
last_name: Sondermann-Wölke
- first_name: Tobias
full_name: Hemsel, Tobias
id: '210'
last_name: Hemsel
- first_name: Walter
full_name: Sextro, Walter
id: '21220'
last_name: Sextro
- first_name: Jürgen
full_name: Gausemeier, Jürgen
last_name: Gausemeier
- first_name: Sebastian
full_name: Pook, Sebastian
last_name: Pook
citation:
ama: 'Sondermann-Wölke C, Hemsel T, Sextro W, Gausemeier J, Pook S. Guideline for
the dependability-oriented design of self-optimizing systems. In: Industrial
Informatics (INDIN), 2010 8th IEEE International Conference On. ; 2010:739-744.
doi:10.1109/INDIN.2010.5549490'
apa: Sondermann-Wölke, C., Hemsel, T., Sextro, W., Gausemeier, J., & Pook, S.
(2010). Guideline for the dependability-oriented design of self-optimizing systems.
In Industrial Informatics (INDIN), 2010 8th IEEE International Conference on
(pp. 739–744). https://doi.org/10.1109/INDIN.2010.5549490
bibtex: '@inproceedings{Sondermann-Wölke_Hemsel_Sextro_Gausemeier_Pook_2010, title={Guideline
for the dependability-oriented design of self-optimizing systems}, DOI={10.1109/INDIN.2010.5549490},
booktitle={Industrial Informatics (INDIN), 2010 8th IEEE International Conference
on}, author={Sondermann-Wölke, Christoph and Hemsel, Tobias and Sextro, Walter
and Gausemeier, Jürgen and Pook, Sebastian}, year={2010}, pages={739–744} }'
chicago: Sondermann-Wölke, Christoph, Tobias Hemsel, Walter Sextro, Jürgen Gausemeier,
and Sebastian Pook. “Guideline for the Dependability-Oriented Design of Self-Optimizing
Systems.” In Industrial Informatics (INDIN), 2010 8th IEEE International Conference
On, 739–44, 2010. https://doi.org/10.1109/INDIN.2010.5549490.
ieee: C. Sondermann-Wölke, T. Hemsel, W. Sextro, J. Gausemeier, and S. Pook, “Guideline
for the dependability-oriented design of self-optimizing systems,” in Industrial
Informatics (INDIN), 2010 8th IEEE International Conference on, 2010, pp.
739–744.
mla: Sondermann-Wölke, Christoph, et al. “Guideline for the Dependability-Oriented
Design of Self-Optimizing Systems.” Industrial Informatics (INDIN), 2010 8th
IEEE International Conference On, 2010, pp. 739–44, doi:10.1109/INDIN.2010.5549490.
short: 'C. Sondermann-Wölke, T. Hemsel, W. Sextro, J. Gausemeier, S. Pook, in: Industrial
Informatics (INDIN), 2010 8th IEEE International Conference On, 2010, pp. 739–744.'
date_created: 2019-05-13T10:25:26Z
date_updated: 2022-01-06T07:04:19Z
department:
- _id: '151'
doi: 10.1109/INDIN.2010.5549490
keyword:
- RailCab
- dependability-critical behavior
- dependability-oriented design
- failure mode
- rail-bound vehicle
- secure self-optimizing systems
- self-optimizing function modules
- optimisation
- railways
- self-adjusting systems
language:
- iso: eng
page: 739 -744
publication: Industrial Informatics (INDIN), 2010 8th IEEE International Conference
on
quality_controlled: '1'
status: public
title: Guideline for the dependability-oriented design of self-optimizing systems
type: conference
user_id: '55222'
year: '2010'
...
---
_id: '9742'
abstract:
- lang: eng
text: New mechatronic systems, called self-optimizing systems, are able to adapt
their behavior according to environmental, user and system specific influences.
Self-optimizing systems are complex and due to their non-deterministic behavior
comprise hidden risks, which cannot be foreseen in the design phase of the system.
Therefore, this paper presents modifications of the current condition monitoring
policy, to be able to cope with this new kind of systems. Beside avoiding critical
situations evoked by self-optimization, the proposed concept uses self-optimization
to increase the dependability of the system. In this case, the concept is applied
to the active guidance module of an innovative rail-bound vehicle.
author:
- first_name: Christoph
full_name: Sondermann-Wölke, Christoph
last_name: Sondermann-Wölke
- first_name: Walter
full_name: Sextro, Walter
id: '21220'
last_name: Sextro
citation:
ama: 'Sondermann-Wölke C, Sextro W. Towards the Integration of Condition Monitoring
in Self-Optimizing Function Modules. In: Future Computing, Service Computation,
Cognitive, Adaptive, Content, Patterns, 2009. COMPUTATIONWORLD ’09. Computation
World: ; 2009:15-20. doi:10.1109/ComputationWorld.2009.47'
apa: Sondermann-Wölke, C., & Sextro, W. (2009). Towards the Integration of Condition
Monitoring in Self-Optimizing Function Modules. In Future Computing, Service
Computation, Cognitive, Adaptive, Content, Patterns, 2009. COMPUTATIONWORLD ’09.
Computation World: (pp. 15–20). https://doi.org/10.1109/ComputationWorld.2009.47
bibtex: '@inproceedings{Sondermann-Wölke_Sextro_2009, title={Towards the Integration
of Condition Monitoring in Self-Optimizing Function Modules}, DOI={10.1109/ComputationWorld.2009.47},
booktitle={Future Computing, Service Computation, Cognitive, Adaptive, Content,
Patterns, 2009. COMPUTATIONWORLD ’09. Computation World:}, author={Sondermann-Wölke,
Christoph and Sextro, Walter}, year={2009}, pages={15–20} }'
chicago: Sondermann-Wölke, Christoph, and Walter Sextro. “Towards the Integration
of Condition Monitoring in Self-Optimizing Function Modules.” In Future Computing,
Service Computation, Cognitive, Adaptive, Content, Patterns, 2009. COMPUTATIONWORLD
’09. Computation World:, 15–20, 2009. https://doi.org/10.1109/ComputationWorld.2009.47.
ieee: C. Sondermann-Wölke and W. Sextro, “Towards the Integration of Condition Monitoring
in Self-Optimizing Function Modules,” in Future Computing, Service Computation,
Cognitive, Adaptive, Content, Patterns, 2009. COMPUTATIONWORLD ’09. Computation
World:, 2009, pp. 15–20.
mla: Sondermann-Wölke, Christoph, and Walter Sextro. “Towards the Integration of
Condition Monitoring in Self-Optimizing Function Modules.” Future Computing,
Service Computation, Cognitive, Adaptive, Content, Patterns, 2009. COMPUTATIONWORLD
’09. Computation World:, 2009, pp. 15–20, doi:10.1109/ComputationWorld.2009.47.
short: 'C. Sondermann-Wölke, W. Sextro, in: Future Computing, Service Computation,
Cognitive, Adaptive, Content, Patterns, 2009. COMPUTATIONWORLD ’09. Computation
World:, 2009, pp. 15–20.'
date_created: 2019-05-13T09:31:52Z
date_updated: 2022-01-06T07:04:19Z
department:
- _id: '151'
doi: 10.1109/ComputationWorld.2009.47
keyword:
- condition monitoring
- mechatronic systems
- rail bound vehicle
- rail guidance module
- self-optimization
- self-optimizing function modules
- condition monitoring
- mechatronics
- railway rolling stock
- self-adjusting systems
language:
- iso: eng
page: 15 -20
publication: 'Future Computing, Service Computation, Cognitive, Adaptive, Content,
Patterns, 2009. COMPUTATIONWORLD ''09. Computation World:'
status: public
title: Towards the Integration of Condition Monitoring in Self-Optimizing Function
Modules
type: conference
user_id: '55222'
year: '2009'
...