Research on Characteristic Analysis and Identification Methods for DC-Side Grounding Faults in Grid-Connected Photovoltaic Inverters

The analysis and accurate identification of DC-side grounding faults in grid-connected photovoltaic (PV) inverters is a critical step in enhancing operation and maintenance capabilities and ensuring the safe operation of PV grid-connected systems. However, the characteristics of DC-side grounding fa...

Full description

Saved in:
Bibliographic Details
Main Authors: Wanli Feng, Lei Su, Cao Kan, Mingjiang Wei, Changlong Li
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/18/13/3243
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849704624774184960
author Wanli Feng
Lei Su
Cao Kan
Mingjiang Wei
Changlong Li
author_facet Wanli Feng
Lei Su
Cao Kan
Mingjiang Wei
Changlong Li
author_sort Wanli Feng
collection DOAJ
description The analysis and accurate identification of DC-side grounding faults in grid-connected photovoltaic (PV) inverters is a critical step in enhancing operation and maintenance capabilities and ensuring the safe operation of PV grid-connected systems. However, the characteristics of DC-side grounding faults remain unclear, and effective methods for identifying such faults are lacking. To address the need for leakage characteristic analysis and fault identification of DC-side grounding faults in grid-connected PV inverters, this paper first establishes an equivalent analysis model for DC-side grounding faults in three-phase grid-connected inverters. The formation mechanism and frequency-domain characteristics of residual current under DC-side fault conditions are analyzed, and the specific causes of different frequency components in the residual current are identified. Based on the leakage current mechanisms and statistical characteristics of grid-connected PV inverters, a multi-type DC-side grounding fault identification method is proposed using the light gradient-boosting machine (LGBM) algorithm. In the simulation case study, the proposed fault identification method, which combines mechanism characteristics and statistical characteristics, achieved an accuracy rate of 99%, which was significantly superior to traditional methods based solely on statistical characteristics and other machine learning algorithms. Real-time simulation verification shows that introducing mechanism-based features into grid-connected photovoltaic inverters can significantly improve the accuracy of identifying grounding faults on the DC side.
format Article
id doaj-art-5347336acef24f349fc6f6f66e4e6364
institution DOAJ
issn 1996-1073
language English
publishDate 2025-06-01
publisher MDPI AG
record_format Article
series Energies
spelling doaj-art-5347336acef24f349fc6f6f66e4e63642025-08-20T03:16:42ZengMDPI AGEnergies1996-10732025-06-011813324310.3390/en18133243Research on Characteristic Analysis and Identification Methods for DC-Side Grounding Faults in Grid-Connected Photovoltaic InvertersWanli Feng0Lei Su1Cao Kan2Mingjiang Wei3Changlong Li4State Grid Hubei Electric Power Research Institute, Wuhan 430074, ChinaState Grid Hubei Electric Power Research Institute, Wuhan 430074, ChinaState Grid Hubei Electric Power Research Institute, Wuhan 430074, ChinaState Grid Hubei Electric Power Research Institute, Wuhan 430074, ChinaSchool of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha 410014, ChinaThe analysis and accurate identification of DC-side grounding faults in grid-connected photovoltaic (PV) inverters is a critical step in enhancing operation and maintenance capabilities and ensuring the safe operation of PV grid-connected systems. However, the characteristics of DC-side grounding faults remain unclear, and effective methods for identifying such faults are lacking. To address the need for leakage characteristic analysis and fault identification of DC-side grounding faults in grid-connected PV inverters, this paper first establishes an equivalent analysis model for DC-side grounding faults in three-phase grid-connected inverters. The formation mechanism and frequency-domain characteristics of residual current under DC-side fault conditions are analyzed, and the specific causes of different frequency components in the residual current are identified. Based on the leakage current mechanisms and statistical characteristics of grid-connected PV inverters, a multi-type DC-side grounding fault identification method is proposed using the light gradient-boosting machine (LGBM) algorithm. In the simulation case study, the proposed fault identification method, which combines mechanism characteristics and statistical characteristics, achieved an accuracy rate of 99%, which was significantly superior to traditional methods based solely on statistical characteristics and other machine learning algorithms. Real-time simulation verification shows that introducing mechanism-based features into grid-connected photovoltaic inverters can significantly improve the accuracy of identifying grounding faults on the DC side.https://www.mdpi.com/1996-1073/18/13/3243photovoltaic grid-connected inverterDC-side grounding faultmechanistic characteristicsstatistical featuresfault diagnosisLGBM algorithm
spellingShingle Wanli Feng
Lei Su
Cao Kan
Mingjiang Wei
Changlong Li
Research on Characteristic Analysis and Identification Methods for DC-Side Grounding Faults in Grid-Connected Photovoltaic Inverters
Energies
photovoltaic grid-connected inverter
DC-side grounding fault
mechanistic characteristics
statistical features
fault diagnosis
LGBM algorithm
title Research on Characteristic Analysis and Identification Methods for DC-Side Grounding Faults in Grid-Connected Photovoltaic Inverters
title_full Research on Characteristic Analysis and Identification Methods for DC-Side Grounding Faults in Grid-Connected Photovoltaic Inverters
title_fullStr Research on Characteristic Analysis and Identification Methods for DC-Side Grounding Faults in Grid-Connected Photovoltaic Inverters
title_full_unstemmed Research on Characteristic Analysis and Identification Methods for DC-Side Grounding Faults in Grid-Connected Photovoltaic Inverters
title_short Research on Characteristic Analysis and Identification Methods for DC-Side Grounding Faults in Grid-Connected Photovoltaic Inverters
title_sort research on characteristic analysis and identification methods for dc side grounding faults in grid connected photovoltaic inverters
topic photovoltaic grid-connected inverter
DC-side grounding fault
mechanistic characteristics
statistical features
fault diagnosis
LGBM algorithm
url https://www.mdpi.com/1996-1073/18/13/3243
work_keys_str_mv AT wanlifeng researchoncharacteristicanalysisandidentificationmethodsfordcsidegroundingfaultsingridconnectedphotovoltaicinverters
AT leisu researchoncharacteristicanalysisandidentificationmethodsfordcsidegroundingfaultsingridconnectedphotovoltaicinverters
AT caokan researchoncharacteristicanalysisandidentificationmethodsfordcsidegroundingfaultsingridconnectedphotovoltaicinverters
AT mingjiangwei researchoncharacteristicanalysisandidentificationmethodsfordcsidegroundingfaultsingridconnectedphotovoltaicinverters
AT changlongli researchoncharacteristicanalysisandidentificationmethodsfordcsidegroundingfaultsingridconnectedphotovoltaicinverters