Ali M. Humada

Photovoltaic Grid-Connected Modeling and Characterization Based on Experimental Results

A grid-connected photovoltaic (PV) system operates under fluctuated weather condition has been modeled and characterized based on specific test bed. A mathematical model of a small-scale PV system has been developed mainly for residential usage, and the potential results have been simulated. The proposed PV model based on three PV parameters, which are the photocurrent, IL, the reverse diode saturation current, Io, the ideality factor of diode, n. Accuracy of the proposed model and its parameters evaluated based on different benchmarks. The results showed that the proposed model fitting the experimental results with high accuracy compare to the other models, as well as the I-V characteristic curve. The results of this study can be considered valuable in terms of the installation of a grid-connected PV system in fluctuated climatic conditions.

Modeling of Photovoltaic Solar Array under Different levels of partial shadow Conditions

Different methods of configuration have been formulated regarding photovoltaic solar power by employing several techniques. This has been done because of the varying conditions so that the loss of power can be minimized. The main factor which decreases energy output of the photovoltaic PV solar systems is partial shadowing. The way the energy output of partially shadowed arrays varies with the system configuration used, has been studied extensively. A huge degree of disorder still exists, particularly with respect to the best modularity grade for these systems. There are two distinct sub-divisions in the systems implemented in the reconfiguration mechanism: reconfigurable solar arrays, and a switching matrix to do a reconfiguration. Using different methods, the proportions of shadowing obstructions were noted to allow for calculation of the likely shadowing losses. The outcomes of this paper on modeling and monitoring are used to evaluate the photovoltaic system with respect to shadowing losses with different levels and their reliance on the system configuration are selected. It has been found that power loss because of varying conditions is majorly due to the decrease in radiance occurring on the photovoltaic array and can be avoided through selecting the suitable configuration and connection. The simulation results show that the output characteristics of the simulator presented better results with that proposed model.

Implementation of 4D/BIM in the Iraqi construction industry

Building information modelling (BIM) is a new technique, which has been innovated from the traditional method to a modern form. BIM should be classified as a modern technique, since it is dealing with digital data. 3D BIM with its time schedule results on 4D/BIM is represented by softwares, such as Naviswork and Syncro, which has an advantage to solve most of the project issues such as clash detection among projects components, visualisation to projects tasks, and other benefits. The aim of this current study is to find out the benefits and challenges of 4D/BIM implementation in the construction projects. The data collection method in this research is done by conducting semi-structured interviews (SSIs) with the senior civil engineer in Al-Najaf hospital project in Iraq, in addition to that there is the extensive literature review about the benefits, challenges and obstacles in the implementation of 4D/BIM. Analysis of the results was conducted by adopting content analysis method (CAM). The results proved that the construction industry in Iraq needs to further support from the government by increasing awareness and financial support for construction companies.