Modified STC Correction Procedure for Assessing PV Module Degradation in Field Surveys

Singh, Hemant Kumar; Dubey, Rahul; Zachariah, Sachin; Narasimhan, K. L.; Arora, B. M.; Kottantharayil, Anil; Vasi, J.

doi:10.1109/pvsc.2017.8520933

Cited by 4 publications

(4 citation statements)

References 2 publications

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“…As mentioned earlier, these criteria are difficult to achieve in the field unless calibrated meshes and equipment to control the module temperature are used. Brief description of IEC 60891‐Procedure 2, 2 Modified IEC 60891‐Procedure 1, 7,8 SIDT procedure, 9 and Anderson procedure 10 are described Data S1, and Equations (S1) to (S13) are used in those procedures.…”

Section: Stc Correction Proceduresmentioning

confidence: 99%

“…Therefore, several techniques have been developed for STC correction of field‐measured I – V curves that require measurement of only one I – V curve in the field without controlling any environmental variables. Following are some of the examples of such STC correction procedures: “Modified IEC 60891‐Procedure 1”, 7,8 “Standard Irradiance and Desired Temperature” (SIDT) procedure, 9 a procedure proposed by Anderson, 10 and Voltage‐Dependent Temperature Coefficient (VDTC) procedure proposed recently by Hishikawa et al 11,12 The IEC 60891 Procedures 1, 2, and 3, Modified IEC 60891 Procedure 1, and VDTC procedure perform STC correction of every point on the I – V curve measured at non‐STC. These will be called “entire curve correction procedures” in this paper.…”

Section: Introductionmentioning

confidence: 99%

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Determining the optimal standard test condition correction procedure for high‐throughput field I–V measurements of photovoltaic modules

Golive

Kottantharayil

Vasi

et al. 2021

Progress in Photovoltaics

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The field-measured current-voltage (I-V) curves of photovoltaic (PV) modules need to be corrected to Standard Test Conditions (STC) in order to estimate the degradation rates. STC correction procedures have various attributes such as accuracy, requirement of minimum number and types of I-V curves, required irradiance range, and the type of correction (specific points or entire I-V curve) that determine their optimality for specific applications. This paper presents the investigation of accuracy and constraints of six different STC correction procedures for high-throughput field I-V measurements through experimental and simulation studies. Following STC correction procedures are considered in this paper: IEC 60891-Procedure 1, IEC 60891-Procedure 2, Modified IEC 60891-Procedure 1, Standard Irradiance and Desired Temperature (SIDT) procedure, Anderson procedure, and Voltage-Dependent Temperature Coefficient (VDTC) Procedure. Eight different simulation models for predicting the performance of PV modules at arbitrary irradiance and temperature are compared, and the simulation model that yields lowest root mean square error and the most accurate estimation of power temperature coefficient is identified. The simulated I-V curves using this model and the experimentally measured I-V curves on a flash tester at different temperatures and irradiances are provided as an input to all of the STC correction procedures. The average percentage errors in correction of maximum power (P max ), open-circuit voltage (V oc ), short-circuit current (I sc ),and fill factor (FF) were determined as a function of irradiance and temperature during measurement. Systematic biases introduced during correction by certain procedures were also identified. Based on the error estimation, constraints of various procedures, and requirements of high-throughput field I-V measurements, the most optimal STC correction procedure was identified. Moreover, the analysis of the root cause of superior performance of this procedure is also presented.

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Section: Stc Correction Proceduresmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Determining the optimal standard test condition correction procedure for high‐throughput field I–V measurements of photovoltaic modules

Golive

Kottantharayil

Vasi

et al. 2021

Progress in Photovoltaics

View full text Add to dashboard Cite

show abstract

“…The remaining IV curves were processed to: 1) correct for irradiance and temperature to enable comparisons across different test conditions [25], 2) remove voltage values less than 10V to avoid inductive ringing, 3) normalize by each curve's maximum I and V values to remove local variations between times the curves were collected, and 4) resample evenly spaced 5V point intervals, ranging from (max(V 0>10V ), min(V oc )) of all curves, resulting in a length of 82 points per IV curve. Irradiance and temperature corrections were derived from [25] as…”

Section: B Data Filtering and Processingmentioning

confidence: 99%

Neural Network-Based Classification of String-Level IV Curves From Physically-Induced Failures of Photovoltaic Modules

et al. 2020

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Accurate diagnosis of failures is critical for meeting photovoltaic (PV) performance objectives and avoiding safety concerns. This analysis focuses on the classification of field-collected string-level current-voltage (IV) curves representing baseline, partial soiling, and cracked failure modes. Specifically, multiple neural network-based architectures (including convolutional and long short-term memory) are evaluated using domain-informed parameters across different portions of the IV curve and a range of irradiance thresholds. The analysis identified two models that were able to accurately classify the relatively small dataset (~400 samples) at a high accuracy (99%+). Findings also indicate optimal irradiance thresholds and opportunities for improvements in classification activities by focusing on portions of the IV curve. Such advancements are critical for expanding accurate classification of PV faults, especially for those with low power loss (e.g., cracked cells) or visibly similar IV curve profiles.

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“…The accuracy of STC correction algorithms considerably impacts the overall uncertainty associated with the field I‐V measurements. In the literature, various STC correction procedures are available such as: IEC 60891‐Procedure 1, Procedure 2, and Procedure 3 1,2 ; Modified IEC 60891‐Procedure 1 3,4 ; Anderson Procedure 5 ; Standard Irradiance and Desired Temperature (SIDT) Procedure 6 ; and IEC 60891‐Procedure 4 (VDTC) 1,7,8 . The comparison of accuracy of six STC correction procedures and the average percentage errors in STC correction of various performance parameters like P max , V oc , I sc , and FF for different irradiance and temperature conditions were previously reported by the authors Golive et al 9 for c‐Si PV modules through experimental and simulation studies.…”

Section: Introductionmentioning

confidence: 99%

Sensitivity of accuracy of various standard test condition correction procedures to the errors in temperature coefficients of c‐Si PV modules

Golive

Kottantharayil

Shiradkar

2022

Progress in Photovoltaics

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The Standard Test Condition (STC) correction procedures are algorithms used for transforming the Photovoltaic (PV) module current-voltage (I-V) data measured at arbitrary conditions back to STC. The PV module Temperature Coefficients are used as inputs by various STC correction procedures and can significantly influence their accuracy. This paper presents the sensitivity analysis of accuracy of six STC correction procedures (IEC 60891-Procedure 1, Procedure 2, Modified IEC 60891-Procedure 1, IEC 60891-Procedure 4 (Voltage Dependent Temperature Coefficient (VDTC) Procedure), Anderson Procedure, and Standard Irradiance and Desired Temperature Procedure) to the errors in the temperature coefficients of P max , V oc , and I sc . Experimentally measured as well as simulated I-V curves of six multi c-Si PV modules were used in this study. IEC 60891-Procedure 4 (Voltage Dependent Temperature Coefficient) that uses a Voltage Dependent Temperature Coefficient which can be calculated using a single measured I-V curve was found to be most robust against errors in the temperature coefficients.

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Modified STC Correction Procedure for Assessing PV Module Degradation in Field Surveys

Cited by 4 publications

References 2 publications

Determining the optimal standard test condition correction procedure for high‐throughput field I–V measurements of photovoltaic modules

Determining the optimal standard test condition correction procedure for high‐throughput field I–V measurements of photovoltaic modules

Neural Network-Based Classification of String-Level IV Curves From Physically-Induced Failures of Photovoltaic Modules

Sensitivity of accuracy of various standard test condition correction procedures to the errors in temperature coefficients of c‐Si PV modules

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