NEW METHOD TO OPTIMIZE NO-LOAD NOISE OF POWER TRANSFORMERS BASED ON CORE DESIGN & TRANSFORMER OPERATING CONDITIONS

This paper introduces a new algorithm to calculate and optimize no-load noise (sound pressure) of power transformers, and to identify iron sheet parameters. The calculation consists of two steps: the 1st step consists in calculating an initial sound pressure level (A-Evaluation) which has approx. 70 % accuracy within a tolerance interval of ±2dB (A). The 2nd step consists in estimating the expected deviation from the initial calculation to reach 90 % accuracy in the final results. This deviation could be due to material handling, quality tolerance, core manufacturing, etc. The optimization process consists of two parts: the 1st part takes place before choosing a certain iron sheet for calculation to identify the sheet parameters required for computational accuracy (“Sheet Optimization”). The 2nd part consists in considering a core design with an undesirable sound pressure level in order to reduce it to an acceptable limit. This part takes into account the other limitations such as no-load losses and transformer dimensions (“Design Optimization”). For new iron sheets in the market, there is no measurement history to rely on. However, the algorithm is also capable of identifying the sheet parameters for calculation based on the available algorithm data base and the magnetostriction measurements of the iron sheet manufacturer

Simulation and Development of Instrumental Setup to Be Used for Cement Grouting of Sand Soil

Most of Arab countries areas are occupied with deserts that is covered with sandy soil. Thus, it is necessary to make use of this huge volume of sand to be as construction materials. It is proven that, sand is initially uneven and unstable. It requires pre-modifications of its primer properties in order to be used as construction materials. One of the common techniques is injecting the sand with binders. Many grouting techniques has been implanted to modify or rehabilitate the structure of soil but for sandy soil the methods has not yet been introduced Therefore, this study aimed at developing simulation and instrumental setup to be used for cement grouting. The simulation has been custom made and utilized to form grouted samples for further investigation. The method of injecting sand is by applying pressure to produce force flow in order to be injected into the sand. After the formation of injected sand samples, an experimental investigation was carried out to determine the basic properties. Shear strength of the sand was recorded before and after grouting. It was found that, the shear strength has increased after injecting the sand with cement and the setup has produced accurate grouted samples with even distribution of the cement mix. The results of the various investigations conclusively proved that grouting can be used as an effective way to improve the strength characteristics significantly and can also contribute to the stabilization of sand

Determining transformer core losses based on investigation of core material behaviour during test and operation – Results

By identifying the characteristic equation of the specific no-load losses of each iron sheet based on the core configuration, it is possible to reach a high level of accuracy in detecting no-load losses over a wide range of flux density. The method is applicable and frequently used for reference as well as for new sheet types that appear on the market. The results presented in this paper are based on one year experience, showing that the total weight and volume of transformers have clearly been reduced

Determining transformer core losses based on investigation of core material behaviour during test and operation – mathematical interpretation

By identifying the characteristic equation of the specific no-load losses of each iron sheet based on the core configuration, it is possible to reach a high level of accuracy in detecting no-load losses over a wide range of flux density. The method is applicable and frequently used for reference as well as for new sheet types that appear on the market. The results presented in this paper are based on one year experience, showing that the total weight and volume of transformers have clearly been reduced

Influence of supply chain management on the sustainable construction industry in Algeria

The construction industry, a pivotal business sector facilitating physical infrastructure and equipment provision, holds a significant indirect influence on diverse industries. This study investigates the role of supply chain management in enhancing sustainable construction practices within the Algerian construction industry. The research delves into the relationship between traditional supply chain management and sustainable construction, employing a quantitative approach. Data collection involved a survey comprising 61 items, utilizing a five-point Likert scale, gathered through an online survey method targeting managers, supervisors, executives, and suppliers in the Algerian construction industry. With 237 participants from construction companies in Algeria, the study utilized Smart PLS for data analysis, confirming a positive relationship between traditional supply chain management and sustainable construction through partial least squares (PLS) path analysis. The findings provide valuable insights for future stakeholders, guiding employers, designers, manufacturers, contractors, and suppliers to enhance supply chain management practices for sustainable construction in Algeria. Consequently, this study offers significant results with practical and theoretical implications, contributing to the integration of sustainable supply chain management in Algerian construction. In summary, the research addresses the relationship challenges between traditional supply chain management and sustainable construction practices in Algeria

A novel collaborative IoD-assisted VANET approach for coverage area maximization

Internet of Drones (IoD) is an efficient technique that can be integrated with vehicular ad-hoc networks (VANETs) to provide terrestrial communications by acting as an aerial relay when terrestrial infrastructure is unreliable or unavailable. To fully exploit the drones' flexibility and superiority, we propose a novel dynamic IoD collaborative communication approach for urban VANETs. Unlike most of the existing approaches, the IoD nodes are dynamically deployed based on current locations of ground vehicles to effectively mitigate inevitable isolated cars in conventional VANETs. For efficiently coordinating IoD, we model IoD to optimize coverage based on the location of vehicles. The goal is to obtain an efficient IoD deployment to maximize the number of covered vehicles, i.e., minimize the number of isolated vehicles in the target area. More importantly, the proposed approach provides sufficient interconnections between IoD nodes. To do so, an improved version of succinct population-based meta-heuristic, namely Improved Particle Swarm Optimization (IPSO) inspired by food searching behavior of birds or fishes flock, is implemented for IoD assisted VANET (IoDAV). Moreover, the coverage, received signal quality, and IoD connectivity are achieved by IPSO's objective function for optimal IoD deployment at the same time. We carry out an extensive experiment based on the received signal at floating vehicles to examine the proposed IoDAV performance. We compare the results with the baseline VANET with no IoD (NIoD) and Fixed IoD assisted (FIoD). The comparisons are based on the coverage percentage of the ground vehicles and the quality of the received signal. The simulation results demonstrate that the proposed IoDAV approach allows finding the optimal IoD positions throughout the time based on the vehicle's movements and achieves better coverage and better quality of the received signal by finding the most appropriate IoD position compared with NIoD and FIoD schemes. © 2013 IEEE

Principle of Georadar and simulation of its operation by the Reflexw software

This paper is devoted to the study by simulating the propagation of electromagnetic waves of ground radar (GPR) in geological environments (heterogeneous). The latter is used as a method of geophysical prospecting based on the analysis of the spread of the diffraction and reflection of electromagnetic waves in high frequency (0.1 MHz to 2.6 GHz). A number of models have been designed to simulate the varieties of geological conditions. We used the method of finite differences in the time domain FDTD method [1], which is based on the code of scientific computing software Reflexw simulation [2]. During the spread of radar signal in a geological environment, we note that the signal decreases because of the phenomenon of absorption and reflection, and we find that the physical setting that has a great influence on the conduct of the wave in different geological environments is the effective permittivity