The Voltage-Ear – An Anomaly in Photovoltaic Systems With Undersized Inverters
This study presents a phenomenon in photovoltaic field installations we call voltage ear. PV installations exhibit the voltage ear under specific conditions where modules generate more power than the inverter can handle. When inverters exceed their power limit it results in inverter clipping, and th...
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2024-01-01
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| author | Ernst Wittmann Claudia Buerhop-Lutz Vincent Christlein Jens Hauch Christoph J. Brabec Ian Marius Peters |
| author_facet | Ernst Wittmann Claudia Buerhop-Lutz Vincent Christlein Jens Hauch Christoph J. Brabec Ian Marius Peters |
| author_sort | Ernst Wittmann |
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| description | This study presents a phenomenon in photovoltaic field installations we call voltage ear. PV installations exhibit the voltage ear under specific conditions where modules generate more power than the inverter can handle. When inverters exceed their power limit it results in inverter clipping, and the solar modules are regulated to operate at a voltage above that at maximum power. This kind of voltage rise leads to a specific pattern in the monitoring data – the voltage ear. In the present study, data from a solar park in France was analyzed. This park featured a high rate of inverter malfunctions, including overheating and fires, resulting in an estimated 5% failure rate and, ultimately, in a complete replacement of inverters. An automated analysis of the monitoring data revealed 32.000 occurrences of excess voltage in 1.65 million data points (2%). Instances of the phenomena were detected and segmented using a K-means sorting algorithm, which yielded a perfect recall value. Analysis of the identified voltage ear conditions showed, that it occurs predominantly during seasons of high irradiance and cool temperatures. Excess voltages of up to 161 V in single strings were observed, increasing the probability for PID and inverter damage. The direct yield loss due to deviation from maximum power point was between 0.02% in January and 0.9% in June. We assume, that the voltage ear is a symptom of system design issues that can result in malfunctioning of inverters and hope that it will be useful as an indicator for identifying design and operation issues. |
| format | Article |
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| institution | Kabale University |
| issn | 1943-0655 |
| language | English |
| publishDate | 2024-01-01 |
| publisher | IEEE |
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| spelling | doaj-art-bf9c8f9beb4745b782402bc4b36b9f202025-01-24T00:00:45ZengIEEEIEEE Photonics Journal1943-06552024-01-011641610.1109/JPHOT.2024.343002910601221The Voltage-Ear – An Anomaly in Photovoltaic Systems With Undersized InvertersErnst Wittmann0https://orcid.org/0009-0000-8537-1748Claudia Buerhop-Lutz1https://orcid.org/0000-0001-5233-6700Vincent Christlein2https://orcid.org/0000-0003-0455-3799Jens Hauch3https://orcid.org/0000-0003-4384-2112Christoph J. Brabec4Ian Marius Peters5https://orcid.org/0000-0002-1725-0909Graduate School in Advanced Optical Technologies (SAOT), Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Erlangen, GermanyHelmholtz-Institut Erlangen-Nuremberg for Renewable Energy (HI ERN), Forschungszentrum Jülich GmbH, Erlangen, GermanyPattern Recognition Lab / Computer Science 5, Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Erlangen, GermanyHelmholtz-Institut Erlangen-Nuremberg for Renewable Energy (HI ERN), Forschungszentrum Jülich GmbH, Erlangen, GermanyHelmholtz-Institut Erlangen-Nuremberg for Renewable Energy (HI ERN), Forschungszentrum Jülich GmbH, Erlangen, GermanyHelmholtz-Institut Erlangen-Nuremberg for Renewable Energy (HI ERN), Forschungszentrum Jülich GmbH, Erlangen, GermanyThis study presents a phenomenon in photovoltaic field installations we call voltage ear. PV installations exhibit the voltage ear under specific conditions where modules generate more power than the inverter can handle. When inverters exceed their power limit it results in inverter clipping, and the solar modules are regulated to operate at a voltage above that at maximum power. This kind of voltage rise leads to a specific pattern in the monitoring data – the voltage ear. In the present study, data from a solar park in France was analyzed. This park featured a high rate of inverter malfunctions, including overheating and fires, resulting in an estimated 5% failure rate and, ultimately, in a complete replacement of inverters. An automated analysis of the monitoring data revealed 32.000 occurrences of excess voltage in 1.65 million data points (2%). Instances of the phenomena were detected and segmented using a K-means sorting algorithm, which yielded a perfect recall value. Analysis of the identified voltage ear conditions showed, that it occurs predominantly during seasons of high irradiance and cool temperatures. Excess voltages of up to 161 V in single strings were observed, increasing the probability for PID and inverter damage. The direct yield loss due to deviation from maximum power point was between 0.02% in January and 0.9% in June. We assume, that the voltage ear is a symptom of system design issues that can result in malfunctioning of inverters and hope that it will be useful as an indicator for identifying design and operation issues.https://ieeexplore.ieee.org/document/10601221/Inverter failureK-means clusteringmonitoring dataPV field inspectionvoltage ear |
| spellingShingle | Ernst Wittmann Claudia Buerhop-Lutz Vincent Christlein Jens Hauch Christoph J. Brabec Ian Marius Peters The Voltage-Ear – An Anomaly in Photovoltaic Systems With Undersized Inverters IEEE Photonics Journal Inverter failure K-means clustering monitoring data PV field inspection voltage ear |
| title | The Voltage-Ear – An Anomaly in Photovoltaic Systems With Undersized Inverters |
| title_full | The Voltage-Ear – An Anomaly in Photovoltaic Systems With Undersized Inverters |
| title_fullStr | The Voltage-Ear – An Anomaly in Photovoltaic Systems With Undersized Inverters |
| title_full_unstemmed | The Voltage-Ear – An Anomaly in Photovoltaic Systems With Undersized Inverters |
| title_short | The Voltage-Ear – An Anomaly in Photovoltaic Systems With Undersized Inverters |
| title_sort | voltage ear x2013 an anomaly in photovoltaic systems with undersized inverters |
| topic | Inverter failure K-means clustering monitoring data PV field inspection voltage ear |
| url | https://ieeexplore.ieee.org/document/10601221/ |
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