Analytical modeling of partially shaded photovoltaic systems

As of today, the considerable influence of select environmental variables, especially irradiance intensity, must still be accounted for whenever discussing the performance of a solar system. Therefore, an extensive, dependable modeling method is required in investigating the most suitable Maximum Power Point Tracking (MPPT) method under different conditions. Following these requirements, MATLAB-programmed modeling and simulation of photovoltaic systems is presented here, by focusing on the effects of partial shading on the output of the photovoltaic (PV) systems. End results prove the reliability of the proposed model in replicating the aforementioned output characteristics in the prescribed setting. The proposed model is chosen because it can, conveniently, simulate the behavior of different ranges of PV systems from a single PV module through the multidimensional PV structure

Dynamic charging of electric vehicle with negligible power transfer fluctuation

High-efficiency inductive power transfer (IPT) with low misalignment effects is a key issue in the dynamic charging of electric vehicle (EV) systems. In this study, an advanced concept of analysis and design of transmitter and receiver coils with a special coil assembly is proposed for the dynamic charging of EVs. In each transmitter coil, large rectangular section is series connected with two zigzag-shaped small rectangular sections. These small sections are back-to-back series connected and located inside the large rectangular section. An adjacent pair of proposed transmitter coils with back-to-back series connection named extended double D (DD)-shaped transmitter is used throughout this paper. The major contribution in the case of the extended DD transmitter is negligible power transfer fluctuation, regardless of any horizontal misalignment of the receiver coil. Justification of the coil design is performed based on its load independent voltage gain and power transfer fluctuation characteristics. Experimental results prove that the power transfer fluctuation with load independent voltage gain is within ±6%, and the efficiency is approximately 93% under horizontal misalignment of receiver coil with an air gap of 140 mm. Finally, a new coil design set with a special arrangement has been proposed to maintain nearly uniform coupling factor and negligible power transfer fluctuation

Investigating the relationship between land use/land cover change and land surface temperature using Google Earth Engine; case study: Melbourne, Australia

The rapid alteration to land cover, combined with climate change, results in the variation of the land surface temperature (LST). This LST variation is mainly affected by the spatiotemporal changes of land cover classes, their geospatial characteristics, and spectral indices. Melbourne has been the subject of previous studies of land cover change but often over short time periods without considering the trade-offs between land use/land cover (LULC) and mean daytimes summer season LST over a more extended period. To fill this gap, this research aims to investigate the role of LULC change on mean annual daytime LST in the hot summers of 2001 and 2018 in Melbourne. To achieve the study’s aim, LULC and LST maps were generated based on the cost-effective cloud-based geospatial analysis platform Google Earth Engine (GEE). Furthermore, the geospatial and geo-statistical relationship between LULC, LST, and spectral indices of LULC, including the Normalised Difference Built-up Index (NDBI) and the Normalised Difference Vegetation Index (NDVI), were identified. The findings showed that the mean daytime LST increased by 5.1 °C from 2001 to 2018. The minimum and maximum LST values were recorded for the vegetation and the built-up area classes for 2001 and 2018. Additionally, the mean daytime LST for vegetation and the built-up area classes increased by 5.5 °C and 5.9 °C from 2001 to 2018, respectively. Furthermore, both elevation and NDVI were revealed as the most influencing factors in the LULC classification process. Considering the R2 values between LULC and LST and their NDVI values in 2018, grass (0.48), forest (0.27), and shrubs (0.21) had the highest values. In addition, urban areas (0.64), bare land (0.62), and cropland (0.61) LULC types showed the highest R2 values between LST regarding their NDBI values. This study highlights why urban planners and policymakers must understand the impacts of LULC change on LST. Appropriate policy measures can be proposed based on the findings to control Melbourne’s future development

Investigating the impacts of COVID-19 lockdown on air quality, surface Urban Heat Island, air temperature and lighting energy consumption in City of Melbourne

The COVID-19 pandemic has threatened city economies and residents' public health and quality of life. Similar to most cities, Melbourne imposed extreme preventive lockdown measures to address this situation. It would be reasonable to assume that during the two phases of lockdowns, in autumn (March) and winter (June to August) 2020, air quality parameters, air temperature, Surface Urban Heat Island (SUHI), and lighting energy consumption most likely increased. As such, to test this assumption, Sentinel 5, ERA-5 LAND, Sentinel 1 and 2, NASA SRTM, MODIS Aqua and Terra, and VIIRS satellite imageries are utilized to investigate the alterations of NO₂, SO₂, CO, UV Aerosol Index (UAI), air temperature, SUHI, and lighting energy consumption factors in the City of Melbourne. Furthermore, satellite imageries of SentiThe results indicate that the change rates of NO₂ (1.17 mol/m2) and CO (1.64 mol/m2) factors were positive. Further, the nighttime SUHI values increased by approximately 0.417 °C during the winter phase of the lockdown, while during the summer phase of the lockdown, the largest negative change rate was in NO₂ (−100.40 mol/m2). By contrast, the largest positive change rate was in SO₂ and SUHI at night. The SO₂ values increased from very low to 330 μm mol/m2, and the SUHI nighttime values increased by approximately 4.8 °C. From the spatial point of view, this study also shows how the effects on such parameters shifted based on the urban form and land types across the City of Melbourne by using satellite data as a significant resource to analyze the spatial coverage of these factors. The findings of this study demonstrate how air quality factors, SUHI, air temperature, and lighting energy consumption changed from pre-lockdown (2019) to lockdown (2020), offering valuable insights regarding practices for managing SUHI, lighting energy consumption, and air pollution

Urban Design and Walkability: Lessons Learnt from Iranian Traditional Cities

Physical activity is connected to public health in many ways, and walking is its most popular form. Modern planning models have been applied to cities to manage rapid urban expansions. However, this practice has led to low level of walkability and strong car-dependency in today’s cities. Hence, this study aims to provide a review of the most promising urban design parameters affecting walkability, using Frank Lawrence’s theory of “Objectively Measured Urban Form” (density, connectivity and accessibility, and mixed-use development) as the basis of discussion. The second part of this paper takes a case study approach, through discussing the main design elements of traditional Iranian cities (mosques, bazaars, residential quarters, and alleyways) and analyses their impacts on promoting walkability. This study concludes that incorporating inherent values of traditional urban design elements will complement modern planning and design practice

SVR-based model to forecast PV power generation under different weather conditions

Inaccurate forecasting of photovoltaic (PV) power generation is a great concern in the planning and operation of stable and reliable electric grid systems as well as in promoting large-scale PV deployment. The paper proposes a generalized PV power forecasting model based on support vector regression, historical PV power output, and corresponding meteorological data. Weather conditions are broadly classified into two categories, namely, normal condition (clear sky) and abnormal condition (rainy or cloudy day). A generalized day-ahead forecasting model is developed to forecast PV power generation at any weather condition in a particular region. The proposed model is applied and experimentally validated by three different types of PV stations in the same location at different weather conditions. Furthermore, a conventional artificial neural network (ANN)-based forecasting model is utilized, using the same experimental data-sets of the proposed model. The analytical results showed that the proposed model achieved better forecasting accuracy with less computational complexity when compared with other models, including the conventional ANN model. The proposed model is also effective and practical in forecasting existing grid-connected PV power generation

Optimization of antireflection coating design using pc1d simulation for c − si solar cell application

Minimizing the photon losses by depositing an anti-reflection layer can increase the conversion efficiency of the solar cells. In this paper, the impact of anti-reflection coating (ARC) for enhancing the efficiency of silicon solar cells is presented. Initially, the refractive indices and reflectance of various ARC materials were computed numerically using the OPAL2 calculator. After which, the reflectance of SiO2, TiO2, SiNx with different refractive indices (n) were used for analyzing the performance of a silicon solar cells coated with these materials using PC1D simulator. SiNx and TiO2 as single-layer anti-reflection coating (SLARC) yielded a short circuit current density (Jsc ) of 38.4 mA/cm2 and 38.09 mA/cm2 respectively. Highest efficiency of 20.7% was obtained for the SiNx ARC layer with n = 2.15. With Double-layer anti-reflection coating (DLARC), the Jsc improved by ∼0.5 mA/cm2 for SiO2 /SiNx layer and hence the efficiency by 0.3%. Blue loss reduces significantly for the DLARC compared with SLARC and hence increase in Jsc by 1 mA/cm2 is observed. The Jsc values obtained is in good agreement with the reflectance values of the ARC layers. The solar cell with DLARC obtained from the study showed that improved conversion efficiency of 21.1% is obtained. Finally, it is essential to understand that the key parameters identified in this simulation study concerning the DLARC fabrication will make experimental validation faster and cheaper