Module trainer of photovoltaic integrated low voltage grid (PV-LV grid) with a variety load

This research is a simulation of the penetration of renewable energy at the primary source. The entire system is a compound system, especially on the load. Load types provide different voltage and current treatment. The simulation is carried out with a mini-grid device consisting of five buses with interface sensors to monitor voltage and current. Photovoltaic grid module (PV)-LV as a trainer, uses two power sources to supply the load to the voltage distribution network module. The loading scenario h two plans, where the difference lies in the type of inductive load (scenario A) and capacitive (scenario B). The types of load consist of incandescent lamps, fluorescent lamps, energy-saving lamps, drilling machines, and soldering tools. Variations in this load to meet predetermined loading scenarios. The PV measurement results show maximum power generation at noon and flowed to the load trainer via a 300W grid-tie inverter of 191.1W. The average load bus voltage increases for scenario A and scenario B by 1.045% and 1.36%, respectively. The result indicates that the integration of PV in low voltage systems positively impacts the voltage profile for both inductive and capacitive loads. The amount of voltage improvement depends on the value of the active power injection of the PV and the load supplied by the system.

Method for Evaluation of the Utility’s and Consumers’ Contribution to the Current and Voltage Distortions at the PCC

In this article, a method that allows sharing responsibilities for the generation of harmonic currents between the utility and consumers powered by one point of common coupling (PCC) is addressed. For these purposes, mathematical modeling of the power supply system (PSS) with two consumers is carried out in order to introduce new indices using the simplest PSS structure as an example. Two indices are introduced that quantify the consumers’ contribution to the distortion of current and voltage at the PCC and that evaluate harmonic emission from the utility side. Experimental tests are carried out where both linear and nonlinear loads are considered, capacitive loads are taken into account, and harmonic distortions from the utility side are modeled to show the applicability of the indices in a wide range of load types. The experiments confirmed the theoretical results and illustrated that the quantitative assessment of the contributions is unambiguous. It suggests that the proposed criterion could be a reasonable basis for further tax policy on harmonic pollution for each consumer at the PCC and for the utility.

High Cognitive Load Situations With Different Conversation Topics Affect Walking Speed and Cognitive Complexity

Walking and talking on the phone are common high-cognitive-load-situations (HCLS; e.g. dual-tasks), requiring extra attentional allocation and increasing perceived stress. We explored whether two load types, 1) single-task (ST) walking or talking on a phone and 2) HCLS walking while talking on a phone, influenced walking and/or cognitive performance among young (n=7; age=23.00±2.08yrs), middle-aged (n=14; age=44.79±7.42yrs), and older (n=15; age=74.47±3.91yrs) adults while controlling for perceived stress. Participants completed 3-minute trials of single-task walking (ST-W), single-task phone conversations with common (e.g., weather; ST-C) and uncommon topics (e.g., life experience; ST-U), and walking while talking on a phone (HCLS-C and HCLS-U). Walking speed was analyzed with 3(ST-W;HCLS-C;HCLS-U) x 3(Age) ANCOVA. HCLS resulted in slower walking speed (p<.001). Older adults exhibited slower speed across conditions compared to young (p=.015). Cognitive complexity (i.e., conversational tone and words greater than six letters (SIXLTR)) on the Linguistic Inquiry and Word Count (LIWC) were analyzed with 2(Cvs.U) x 2(STvs.HCLS) x 3(Age) ANCOVAs. Older age was associated with less cognitive complexity; positive tone (p=.014) and SIXLTR (p=.016), respectively in conversations. Uncommon topics reduced positive tone (p=.022) and SIXLTR (p=.003). Effects of HCLS on tone (p=.040) and SIXLTR (p=.005) varied with age. HCLS with different conversation topics resulted in reduced walking and cognitive complexity while controlling for perceived stress. The analysis of cognitive complexity using common/uncommon conversation topics is a novel method to assess the impact of HCLS. This research will disrupt the transformation of aging leading to a better understanding of attentional allocation and its effects on function.

Experimental Determination of Parameters of Nonlinear Electrical Load

The paper deals with issues of modeling nonlinear electrical loads of various types, such an uncontrolled rectifier, thyristor rectifier, thyristor power regulator and mixed equivalent nonlinear load. For these load types, existing analytical expressions were identified to determine the magnitudes of harmonic currents, and waveforms of currents were obtained during measurements in laboratory conditions with variable parameters of the grid impedance and load. The obtained results were compared, and it was found that the error in determining the magnitudes of harmonic currents can reach 60% for an individual load and 54% for an equivalent load. A more accurate method for determining the parameters of nonlinear electrical load is also proposed, which is based on the application of shunt harmonic filters. In laboratory conditions, it was found that when using the developed method, the error did not exceed 10% for an individual load and 14% for an equivalent load.

Binary Logistic Regression Approach for Decision Making in Bridge Management

Bridge management professionals need effective tools to help guide the decision-making process and maintain quality infrastructure in a region. A new binary response is herein defined by categorizing bridges as at-risk and not at-risk, based on the existing overall bridge condition scores. Fitting binary logistic regression model for the response, the probability of a bridge being at-risk is expressed in terms of the primary bridge factors age, load, types of construction material and structural design, and conditions of the deck, superstructure, and substructure. These estimated probabilities multiplied by specified consequence values are used to introduce the risk classes and their ranks. Employing the method for training and validating sets of sizes 13,540 and 3,385 in 2017, and 13,481 and 3,370 in 2018 data in National Bridge Inventory (NBI) Indiana, a statistically significant model is established containing age, load, conditions of both superstructure and substructure. Moreover, at-risk bridges are identified from Indiana NBI data in both years and for a subset from Connecticut in 2017. The novel bridge-ranking tool prioritizes bridges for maintenance purposes such as replacing or repairing and hence efficiently guides the management in the decision-making process for capital expenditures, and perhaps, for predicting the missing overall bridge condition.

Torsional Vibration Control of a Structure using Fluid Viscous Dampers

Damping plays a major role in design of structures resistant to earthquakes. The damping reduces the effective of the structure when they are assigned to lateral loads by energy dissipation. The number of dampers is available and in use today. Most of the dampers usually isolate the super structure from the substructure, dividing them in order to hamper the flow of vibrations into the superstructure. This classification is termed as base isolation techniques. While, the rest of the damping techniques, dissipates the oncoming vibrations on the superstructure itself and minimizes the damage to the superstructure. In this present study, Fluid Viscous Dampers (FVD) are used extensively over types of dampers. The structure endures two load types, the vertical loads and the sidewise loads, and conveys to the foundation. In order to have earthquake resistant structures, FVD have been used. In the present study, Dissymmetric Buildings are analyzed with and without Fluid Viscous Dampers. The software ETABS 2016 was used. Using Time history analysis in ETABS software, the RC building is considered and the structure is evaluated and connect with and without FVD.

Methodological approaches for quantitative assessment of health risk associated with the labour process strength

Introduction. Labour employment of the population is increasingly associated with mental activity and is characterized by increasing stress. The article presented and tested methodical approaches to the quantitative health risk assessment associated with the labour process strength (LPS), taking into account it’s detailing by type of load. Materials and methods. In the course of the work, analytical, epidemiological, and statistical methods were used. The proposed approaches were tested on the example of assessing the health risk of male employees of oil and gas production operators (OGPO), aged from 26 to 59 years (average age: 44.51 ± 8.01 years) with work experience in the profession of from 3 up to 33 years old (average experience 17.05 ± 8.89 years). Results. The developed algorithm for assessing the health risk associated with LPS includes using a tool (checklist), which will allow, along with a comprehensive assessment, assessing detailed types of loads - intellectual, emotional, sensory, monotony mode of work. The checklist contains the specified characteristics of the LPS assessment indicators and criteria that allow us to weigh the degree of tension (0 - there is no effect on this indicator, 4 - the influence on the indicator is most pronounced). The procedure provides for a quantitative assessment of occupational health risk and determination of the contribution of detailed load types to the formation of risk. The results of testing confirm the validity of the proposed approaches. The risk of developing a gastric ulcer and duodenal ulcer due to sensory load was revealed to be 2 • 10-2 and was classified as medium. As a result of exposure to sensory load and operating mode, the risk of developing atherosclerosis is 5.7 • 10-2 and 9.8 • 10-2, respectively, and classified as high. The risk of developing atherosclerosis associated with exposure to two significant LPS components is 14.9 ∙ 10-2. In this case, the contribution of the load associated with the mode of work in the development of atherosclerosis is more significant (66%) than the sensory (34%) load. Conclusion. The developed methods to assess the intensity of the labor process allow moving on to a quantitative assessment of risk and identifying the role (contribution) of individual, detailed types of loads in the formation of occupational health risks, and determining targeted preventive measures.

Research Progress of Coal Damage under Unsteady Load in China

Coalbed methane mining, suppression of coal dust, and elimination of dynamic disasters are closely related to the expansion of coal body cracks and internal damage. Understanding the expansion mechanism of pore-cracks is critical to investigate coal body damage. In this study, research from 2016 to 2021 conducted on the coal damage mechanism in China was sorted and the progress in this field was analysed to systematically investigate coal body damage. Critical topics of research in this field in recent years were identified, and load types were classified into static and dynamic loads. Dynamic loads with obvious characteristics and considerable damage-increasing effects were classified into impacting, cyclic, pulsating, and other dynamic load types. The current load-generating devices, various detection techniques and methods, research results, and the future research directions under various load types were discussed. The current coal damage research is primarily based on macrocharacteristic analysis and the stage characteristics of characterisation variables. The use of scanning electron microscopy, computerised tomography three-dimensional reconstruction technology, and acoustic emission technology can reveal the pore propagation mechanism at the micro level.

THE BEHAVIOR OF THE SOIL UNDER FOUNDATION OF OFFSHORE GRAVITY STRUCTURES SUBJECTED TO DIFFERENT COMBINATION OF LOADS

This study aims at analyzing the behavioral rules of the soil under the bottom of the offshore gravity structures when it had been subjected to the combination of load types; in which the problem of determining the deformation of the ground in semi-infinite space is determined by the view of deformed solid mechanics and elastic theory. The ground plane displacement of the soil is simulated by the computer when the structural system is subjected to concentrated loads and the distribution load is consist of the eccentricity due to wave load and other horizontal loads.