Drive modelling and performance estimation of IPM motor using SVPWM and Six-step Control Strategy

2021 ◽  
Keyword(s):  
Comprehensive Evaluation ◽  
Element Model ◽  
Torque Ripple ◽  
Performance Estimation ◽  
Smooth Transition ◽  
Motor Speed ◽  
Traction Motor ◽  
Modulation Techniques ◽  
And Performance ◽  
The Impact

This paper presents a comprehensive evaluation of the performance of an interior permanent magnet (IPM) traction motor drive, and analyses the impact of different modulation techniques. The most widely used modulation methods in traction motor drives are Space vector modulation (SVPWM), over-modulation, and six-step modulation have been implemented. A two-dimensional electromagnetic finite element model of the motor is co-simulated with a dynamic model of a field-oriented control (FOC) circuit. For accurate tuning of the current controllers, extended complex vector synchronous frame current regulators are employed. The DC-link voltage utilization, harmonics in the output waveforms, torque ripple, iron losses, and AC copper losses are calculated and compared with sinusoidal excitation. Overall, it is concluded that the selection of modulation technique is related to the operating condition and motor speed, and a smooth transition between different modulation techniques is essential to achieve a better performance.

Performance Trends for Portland Cement Concrète General Aviation Pavements in Illinois

1996 ◽  
Vol 1524 (1) ◽  
pp. 194-202 ◽  
Author(s):  
Thomas Van Dam ◽  
James Bildilli
Keyword(s):  
Portland Cement ◽  
Element Model ◽  
General Aviation ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Actual Performance ◽  
Deterioration Rate ◽  
Performance Trends ◽  
And Performance ◽  
The Impact

The deterioration and performance of portland cement concrete general aviation (GA) airport pavements in Illinois are discussed. Two popular design procedures are reviewed, and typical GA pavement sections are structurally evaluated by using the ILLI-SLAB finite-element model. Subjected to GA pavement loading conditions, 125- and 150-mm-thick slabs would be considered structurally adequate, whereas 100-mm-thick slabs would not be expected to perform well. It was determined that slab size, as determined by the ratio of the slab length over the radius of relative stiffness (L/ l) was strongly correlated to pavement distress and performance. As the slab size was increased higher incidences of distress at higher severity levels were observed. Performance trends were identified by using a deterioration rate approach that accounts for the performance of individual sections. It is believed that this procedure reflects actual performance trends by addressing the issues of long-lived pavement sections, the impact of maintenance, and the influence of inspection variability.

scholarly journals CHINESE AIRLINE COMPETITIVENESS EVALUATION BASED ON EXTENDED BINARY RELATIVE EVALUATION(BRE) MODEL

2013 ◽  
Vol 14 (Supplement_1) ◽  
pp. S227-S256 ◽  
Author(s):  
Chong Wu ◽  
Xin Wang ◽  
Xinying Zhang ◽  
Yongli Li ◽  
Brad O’Brien
Keyword(s):  
Comprehensive Evaluation ◽  
Evaluation Model ◽  
Evaluation Index System ◽  
Analytic Hierarchy ◽  
Index Set ◽  
Evaluation Indexes ◽  
Model Based ◽  
And Performance ◽  
Improved Model ◽  
The Impact

In order to eliminate the impact of the sample's objective merits on the evaluation results, this research built a two-stage model of Chinese airline competitiveness evaluation to reflect the subjective management and performance. In the first stage, Analytic Hierarchy Process (AHP) and Factor Analysis (FA) models were used to analyze the data from 2008 to 2009. In the second stage, two kinds of comprehensive evaluation indexes in 2008 were taken as the reference index set, and two kinds of comprehensive evaluation indexes in 2009 as the current index set. The four sets of data were calculated with the Group Decision-making Model Based on Data Envelopment Analysis (DEA) with Restraint Cone. This paper has (1) enriched the theory of airline competitiveness,(2) built a more scientific and comprehensive evaluation index system of airlines’ competitiveness, (3) constructed a competitiveness evaluation model based on BRE, and (4) conducted an empirical study of the improved model based on the 2008 and 2009 data from 15 Chinese airlines. The ranking results of the proposed method, theory and model coincide with the real conditions of the airline market demonstrating that our evaluation of airline competitiveness based on BRE is accurate, reliable and objective.

scholarly journals Optimal Design Parameters of a Percussive Drilling System for Efficiency Improvement

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Changheon Song ◽  
Jintai Chung ◽  
Jae-Sang Cho ◽  
Yun-Joo Nam
Keyword(s):  
Optimal Design ◽  
Resistance Coefficient ◽  
Rock Breaking ◽  
Performance Estimation ◽  
Design Parameters ◽  
Percussive Drilling ◽  
Rock Interaction ◽  
Breaking Mechanism ◽  
And Performance ◽  
The Impact

This paper aims to determine the optimal design parameters for percussive drilling systems considering the bit-rock interaction. First, the motion dynamics of a bit impacted by a dropped piston are modeled by impact stress propagation and a rock-breaking mechanism representing the penetration resistance coefficient and unloading constant. Next, the damping vibration behavior of the bit is investigated considering the impact duration and the rock loading/unloading condition. In addition, the proposed dynamics are simplified by adopting two dimensionless parameters representing the bit-piston mass ratio and the rock-piston stiffness ratio. Finally, the drilling efficiency, defined by the energy transmitted from the piston to the rock, is presented in terms of the proposed parameters. The use of optimal design parameters for percussive drilling systems improved the drilling efficiency. These results are applicable to the design and performance estimation of down-the-hole and top-hammer systems.

The Impact of Property Characteristics on Economic Performance of Russian Industrial Enterprises

2005 ◽  
pp. 53-68 ◽  
Author(s):  
R. Kapeliushnikov ◽  
N. Demina
Keyword(s):  
Detailed Analysis ◽  
Economic Performance ◽  
Ownership Concentration ◽  
Corporate Sector ◽  
Concentrated Ownership ◽  
Industrial Enterprises ◽  
Russian Industry ◽  
Control Premium ◽  
And Performance ◽  
The Impact

The paper provides new survey evidence on effects of concentrated ownership upon investment and performance in Russian industrial enterprises. Authors trace major changes in their ownership profile, assess pace of post-privatization redistribution of shareholdings and provide evidence on ownership concentration in the Russian industry. The major econometric findings are that the first largest shareholding is negatively associated with the firm’s investment and performance but surprisingly the second largest shareholding is positively associated with them. Moreover, these relationships do not depend on identity of majority shareholders. These results are consistent with the assumption that the entrenched controlling owners are engaged in extracting "control premium" but sizable shareholdings accumulated by other blockholders may put brakes on their expropriating behavior and thus be conductive for efficiency enhancing. The most interesting topic for further more detailed analysis is formation, stability and roles of coalitions of large blockholders in the corporate sector of post-socialist countries.

The Impact of Women’s Employment on Marital Stability in Qatar Society

2019 ◽  
Vol 10 (2) ◽  
pp. 144-151
Author(s):  
Noora Ahmed Lari ◽  
Keyword(s):  
Work Motivation ◽  
Marital Stability ◽  
Female Employment ◽  
Social Constraints ◽  
Primary Data ◽  
Family Policies ◽  
Insufficient Time ◽  
And Performance ◽  
The Impact ◽  
The Relationship

The State of Qatar has implemented several family policies in order to improve the wellbeing of Qatari families and ensure fair distribution of development benefits for both men and women. However, there is a linkage between female employment outside the home and instability in the marriages of Qatari families. This paper investigates the impact of female employment on marital stability, based on the results of primary data collected in Qatar, a questionnaire that consisted of several sections such as challenges in the workplace, supervisor, family and spouse relations, work motivation and performance. Of the 824 questionnaires that were returned, 807 were completed and valid for analysis. Regression analysis and an ANOVA test have been used to test the relationship between the variables. The results of the research have produced mixed findings about how wives’ employment increases marital instability and have yielded few significant differences on mean scores of discuss on work demands, insufficient time together, housework, financial matters, communication, relatives and rearing children. The results indicates that in general Qatar working women face several challenges in relation to their marital life as part of cultural and social constraints.

The Role of Research and Innovation in the Transformation of Agri-Food Systems

2018 ◽  
Vol 12 (2) ◽  
pp. 60-63
Author(s):  
Mariana Sandu ◽  
Stefan Mantea
Keyword(s):  
Technological Progress ◽  
Food Systems ◽  
Food System ◽  
Agricultural Research ◽  
Research And Innovation ◽  
And Performance ◽  
The Impact ◽  
Determinant Factor ◽  
Rapid Transformation

Abstract Agri-food systems include branching ramifications, which connect in the upstream the input suppliers with farmers, and downstream farmers, processors, retailers and consumers. In the last decades, at the level of the regions, food systems have undergone rapid transformation as a result of technological progress. The paper analyzes the changes made to the structure, behavior and performance of the agri-food system and the impact on farmers and consumers. Also, the role of agricultural research as a determinant factor of transformation of agri-food system is analyzed. The research objective is to develop technologies that cover the entire food chain (from farm to fork) and meet the specific requirements of consumers (from fork to farm) through scientific solutions in line with the principles of sustainable agriculture and ensuring the safety and food safety of the population.

Analyzing the impact of financial momentum on the development of the economy

2020 ◽  
Vol 26 (2) ◽  
pp. 299-315
Author(s):  
V.V. Smirnov
Keyword(s):  
Financial Regulation ◽  
Systems Approach ◽  
Financial System ◽  
Modern Economic ◽  
And Performance ◽  
The Interest Rate ◽  
National Economies ◽  
Economic Ties ◽  
The Impact ◽  
Global Financial System

Subject. The article discusses the momentum in finance. Objectives. The study reveals the impact of financial momentum as the unity of antipodes in the development of the national economy. Methods. The study is based on a systems approach and methods of descriptive statistics. Results. I discover the ultimate goal of globalization, i.e. the substantive simplification of national economies and strengthening of global economic ties. The goals determine the logic tendency of national economies for reducing the interest rate so as to gain the financial momentum and, consequently, fanning the crisis risk in the global financial system. The global financial system became the substance of global economic processes, which determined development opportunities of national economies. I reveal what countries have the high and low financial momentum. Conclusions and Relevance. Being the unity of antipodes in the modern economic development, financial momentum causes countries to lose their economic identity, making them just functions of the global financial system. The cyclical development model of national economies is replaced with the metron model that rests on fluctuating advanced economies with the low financial momentum at its bottom and emerging economies at its top. The findings crystallize the concept and new competencies for a person who decide on the determination and performance of financial regulation activities.

From strategic human resources to organization performance

2014 ◽  
Author(s):  
Ana Rita Damas Oliveira ◽  
Paulo Alexandre Guedes Lopes Henriques ◽  
Teresa Cristina Clímaco Monteiro de Oliveira
Keyword(s):  
Human Resources ◽  
Business Strategy ◽  
Organization Performance ◽  
Case Study Methodology ◽  
Strategic Human Resources ◽  
The People ◽  
Sustainable Advantage ◽  
Strategy Alignment ◽  
And Performance ◽  
The Impact

Much has been written about the link between HR and performance, however consensus has yet not been found concerning the understanding on how that relationship comes together. Empirically, no direct impact has been found and research has only suggested an indirect impact. Consequently, the Strategic HRM field is particularly interested on the understanding of the mediating variables that impact the organization performance. Besides the integrated and business strategy alignment of the HR function, it should be considered that it is the people (HR) of the organization and not their practices that determine the company´s competitive advantage. (Messersmith & Guthrie, 2010) argue that it is the impact of those practices that represent “the true resource and enable a sustainable advantage over industry rivals”. The objetive of this research proposal is to study the impact of strategic human resources practices on the organization performance through a case study methodology, supported by longitudinal data. Namely, the project aims to achieve a deeper understanding of the variables that affect the process stream during strategy implementation. How the HR practices impact on people? And why human resources are the most valuable asset? These core premises are in line with the most recent economic concerns about people productivity, employment policies and labor flexibility.

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