Detecting Defective Bypass Diodes in Photovoltaic Modules using Mamdani Fuzzy Logic System

In this paper, the development of fault detection method for PV modules defective bypass diodes is presented. Bypass diodes are nowadays used in PV modules in order to enhance the output power production during partial shading conditions. However, there is lack of scientific research which demonstrates the detection of defective bypass diodes in PV systems. Thus, this paper propose a PV bypass diode fault detection classification based on Mamdani fuzzy logic system, which depends on the analysis of Vdrop, Voc , and Isc obtained from the I-V curve of the examined PV module. The fuzzy logic system depends on three inputs, namely percentage of voltage drop (PVD), percentage of open circuit voltage (POCV), and the percentage of short circuit current (PSCC). The proposed fuzzy system can detect up to 13 different faults associated with defective and non-defective bypass diodes. In addition, the proposed system was evaluated using two different PV modules under various defective bypass conditions. Finally, in order to investigate the variations of the PV module temperature during defective bypass diodes and partial shading conditions, i5 FLIR thermal camera was used

Output Power Enhancement for Hot Spotted Polycrystalline Photovoltaic Solar Cells

Hot spotting is a reliability problem in photovoltaic (PV) panels where a mismatched cell heats up significantly and degrades PV panel output power performance. High PV cell temperature due to hot spotting can damage the cell encapsulate and lead to second breakdown, where both cause permanent damage to the PV panel. Therefore, the development of two hot spot mitigation techniques are proposed using a simple and reliable method. PV hot spots in the examined PV system was inspected using FLIR i5 thermal imaging camera. Multiple experiments have been tested during various environmental conditions, where the PV module I-V curve was evaluated in each observed test to analyze the output power performance before and after the activation of the proposed hot spot mitigation techniques. One PV module affected by hot spot was tested. The output power during high irradiance levels is increased by approximate to 1.26 W after the activation of the first hot spot mitigation technique. However, the second mitigation technique guarantee an increase in the power up to 3.97 W. Additional test has been examined during partial shading condition. Both proposed techniques ensure a decrease in the shaded PV cell temperature, thus an increase in the PV output power

GRAFPAC: FDTOPC, GRID, CONVRT, CONTUR, SURFAC, PRTGRF, and SNKGRF postprocessors for Illinois State Water Survey numerical groundwater models

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Photovoltaic fault detection algorithm based on theoretical curves modelling and fuzzy classification system

This work proposes a fault detection algorithm based on the analysis of the theoretical curves which describe the behavior of an existing PV system. For a given set of working conditions, solar irradiance and PV modules' temperature, a number of attributes such as voltage ratio (VR) and power ratio (PR) are simulated using virtual instrumentation (VI) LabVIEW software. Furthermore, a third order polynomial function is used to generate two detection limits for the VR and PR ratios obtained using VI LabVIEW simulation tool. The high and low detection limits are compared with measured data taken from 1.1 kWp PV system installed at the University of Huddersfield, United Kingdom. Samples lie out of the detection limits are processed by a fuzzy logic classification system which consists of two inputs and one output membership function. In this paper, PV faults corresponds to a short circuited PV module. The obtained results show that the fault detection algorithm can accurately detect different faults occurring in the PV system, where the maximum detection accuracy of before considering the fuzzy logic system is equal to 95.27%. However, the fault detection accuracy is increased up to a minimum value of 98.8% after considering the fuzzy system

PV output power enhancement using two mitigation techniques for hot spots and partially shaded solar cells

Hot spotting is a reliability problem in photovoltaic (PV) panels where a mismatched cell heats up significantly and degrades PV panel output power performance. High PV cell temperature due to hot spotting can damage the cell encapsulate and lead to second breakdown, where both cause permanent damage to the PV panel. Therefore, the design and development of two hot spot mitigation techniques are proposed using a simple, costless and reliable method. The hot spots in the examined PV system was carried out using FLIER i5 thermal imaging camera. Several experiments have been examined during various environmental conditions, where the PV module I-V curve was evaluated in each observed test to analyze the output power performance before and after the activation of the proposed hot spot mitigation techniques. One PV module affected by hot spot was tested. The output power during high irradiance levels is increased by approximate to 1.25 W after the activation of the first hot spot mitigation technique. However, the second mitigation technique guarantee an increase of the power equals to 3.96 W. Additional test has been examined during partial shading condition. Both proposed techniques ensure a decrease in the shaded PV cell temperature, thus an increase in the output measured power

Cross-sectional survey of patients in receipt of long-term repeat prescriptions for antidepressant drugs in primary care

This cross-sectional survey describes the clinical characteristics of 92 patients from across 12 general medical practices, in receipt of a long-term repeat prescription of an antidepressant for the treatment of depression. Psychiatric diagnoses were determined using the Schedule for Clinical Assessment in Neuropsychiatry. Fifty-three participants (57.6%) failed to meet criteria for any psychiatric diagnosis (95% confidence interval (CI): 47.5–67.7%). Independent clinical assessments based upon diagnoses and other clinical data indicated that 26 (31.0%) participants (95% CI: 28.9–49.7%) had no clear clinical reason for continued receipt of an antidepressant. Reasons for the continued use of antidepressants in this population require further investigation

Cross-sectional survey of patients in receipt of long-term repeat prescriptions for antidepressant drugs in primary care

This cross-sectional survey describes the clinical characteristics of 92 patients from across 12 general medical practices, in receipt of a long-term repeat prescription of an antidepressant for the treatment of depression. Psychiatric diagnoses were determined using the Schedule for Clinical Assessment in Neuropsychiatry. Fifty-three participants (57.6%) failed to meet criteria for any psychiatric diagnosis (95% confidence interval (CI): 47.5–67.7%). Independent clinical assessments based upon diagnoses and other clinical data indicated that 26 (31.0%) participants (95% CI: 28.9–49.7%) had no clear clinical reason for continued receipt of an antidepressant. Reasons for the continued use of antidepressants in this population require further investigation

Disguise and Deception of Action Outcomes Through Sports Garment Design Impair Anticipation Judgments.

The ability to disguise and deceive action outcomes was examined by manipulating sports garments. In Experiment 1, those with higher and lower skill levels in anticipation predicted the throw direction of an opponent who wore a garment designed to disguise kinetic-chain information. Higher skill anticipators were more adversely affected by the disguise garment than the lower skill anticipators, demonstrating that disguise removed the anticipation advantage. In Experiment 2, using the same occlusion methodology, the effect of deception was examined using 2 garments designed to create visual illusions of motion across the proximal-to-distal sequence of the thrower's action and compared with a white-garment control. Performances for the deceptive garments were reduced relative to the control garment at the earliest occlusion points for the rightmost targets, but this effect was reversed for the leftmost targets at the earliest occlusion point, suggesting that the visual illusion garments were deceiving participants about motion information from the proximal-to-distal sequence of the action

The efficacy of playing a virtual reality game in modulating pain for children with acute burn injuries: A randomized controlled trial [ISRCTN87413556]

BACKGROUND: The management of burn injuries is reported as painful, distressing and a cause of anxiety in children and their parents. Child's and parents' pain and anxiety, often contributes to extended time required for burns management procedures, in particular the process of changing dressings. The traditional method of pharmacologic analgesia is often insufficient to cover the burnt child's pain, and it can have deleterious side effects [1,2]. Intervention with Virtual Reality (VR) games is based on distraction or interruption in the way current thoughts, including pain, are processed by the brain. Research on adults supports the hypothesis that virtual reality has a positive influence on burns pain modulation. METHODS: This study investigates whether playing a virtual reality game, decreases procedural pain in children aged 5–18 years with acute burn injuries. The paper reports on the findings of a pilot study, a randomised trial, in which seven children acted as their own controls though a series of 11 trials. Outcomes were pain measured using the self-report Faces Scale and findings of interviews with parent/carer and nurses. RESULTS: The average pain scores (from the Faces Scale) for pharmacological analgesia only was, 4.1 (SD 2.9), while VR coupled with pharmacological analgesia, the average pain score was 1.3 (SD 1.8) CONCLUSION: The study provides strong evidence supporting VR based games in providing analgesia with minimal side effects and little impact on the physical hospital environment, as well as its reusability and versatility, suggesting another option in the management of children's acute pain