Analytical modeling of axial flux PM machines with eccentricities

© 2017 IOS Press and the authors. All rights reserved. In this paper, an analytical quasi three-dimensional method is used to model an axial flux permanent magnet (AFPM) machine with various eccentricities. AFPM machines (AFPMMs) have various advantages but they are sensitive to geometrical imperfections for manufacturing aspect. The main aim of this paper is to propose a general analytical model to analyze the AFPMMs with various types of eccentricities. The radial and tangential magnetic flux densities in the air gap under healthy condition are obtained via combination of Maxwell's equations and Schwarz-Christoffel (SC) mapping firstly. Next, in order to investigate the eccentricities, equations for air gap length and radii are deduced. The back electromotive force (EMF) is calculated and compared with those from healthy condition and finite element (FE) analysis, respectively. The results show that the analytical predictions agree well with the FE results. Moreover, using this method has a significantly less time consuming than the 3D FM simulation process, which is a great advantage of this method. Finally, the analytical model is verified via experimental results

Impact of loading capability on optimal location of renewable energy systems distribution networks

Copyright © 2023 The Authors. A distribution system's network reconfiguration is the process of altering the open/closed status of sectionalizing and tie switches to change the topological structure of distribution feeders. For the last two decades, numerous heuristic search evolutionary algorithms have been used to tackle the problem of network reconfiguration for time-varying loads, which is a very difficult and highly non-linear efficiency challenge. This research aims to offer an ideal solution for addressing network reconfiguration difficulties in terms of a system for power distribution, to decrease energy losses, and increase the voltage profile. A hybrid Genetic Archimedes optimization technique (GAAOA) has also been developed to size and allocate three types of DGs, wind turbine, fuel cell and PV considering load variation. This approach is quite useful and may be used in many situations. This technique is evaluated for loss reduction and voltage profile on a typical 33-bus radial distribution system and a 69-bus radial distribution system. The system has been simulated using MATLAB software. The findings suggest that this approach is effective and acceptable for real-time usage

Investigation of six-phase surface permanent magnet machine with typical slot/pole combinations for integrated onboard chargers through methodical design optimization

This article presents an analytical magnetic equivalent circuit (MEC) modeling approach for a six-phase surface-mounted permanent magnet (SPM) machine equipped with fractional slot concentrated winding (FSCW) for integrated onboard chargers. For the sake of comparison, the selected asymmetrical six-phase slot/pole combinations with the same design specifications and constraints are first designed based on the parametric MEC model and then optimized using a multiobjective genetic algorithm (MOGA). The commercial BMW i3 design specifications are adopted in this article. The main focus of this study is to achieve optimal design of the SPM machine considering both the propulsion and charging performances. Thus, a comparative study of the optimization cost functions, including the peak-to-peak torque ripple and core losses under both motoring and charging modes and electromagnetic forces (EMFs) under charging, is conducted. In addition, the demagnetization capability in the charging mode and the overall cost of the employed machines are optimized. Since the average propulsion torque is crucial in electric vehicle (EV) applications, it is maintained through the design optimization process. Furthermore, finite element (FE) simulations have been carried out to verify the results obtained from the analytical MEC model. Eventually, the effectiveness of the proposed design optimization process is corroborated by experimental tests on a 2-kW prototype system

Advocacy training for young family doctors in primary mental health care: A report and global call to action

Background The World Health Organization (WHO) recognises the essential role of mental health in achieving health for all; its mental health action plan calls for more effective leadership for mental health and the provision of community-based, integrated care. 1 However, integrating mental health care into primary care is a challenging, transformational change that requires more than clinical knowledge. 2 It depends on strong advocacy, leadership, and change management: skills that can be learnt. 3,4 Project The Farley Health Policy Centre (FHPC) partnered with the World Organization of Family Doctors (WONCA) to develop and pilot a global curriculum to enable learners to lead practice transformation and be empowered with policy-influencing skills to advocate for their patients, to promote and enhance primary care mental health. We recruited 12 young family doctors, of whom seven were women and ten were from low- and middle-income countries (LMICs), as shown in Figure 1. The programme began with a survey of learners' needs and aspirations, and an expectation that each would self-identify a practice transformation goal. Faculty and learners took part in a two-phase learning evaluation. Funding from WONCA was provided for logistics and evaluation. A small stipend was offered to each learner on successful course completion. Faculty gave their time pro bono. The programme was conducted between March and October 2020. The evaluation process was approved by the University of Liverpool Health and Life Sciences Research Ethics Committee. The learners were divided into two learning cohorts. Sessions were facilitated by two leaders and supported by four mentors. The educational content was delivered twice (to accommodate differing time zones) in six 90-minute monthly virtual sessions. The topics were: • Introduction to mental health integratio

Noise utilization as an approach for reducing energy consumption in street lighting.

Noise is considered as one of the challenging problems in big cities. However, this noise could be utilized in producing energy especially in dense urban areas. Sound as a form of mechanical energy, it can be converted to electric energy through many approaches including heating, by using the diaphragm and through using piezoelectric materials. This research aims at utilizing noise through using piezoelectric materials as an approach of conversion to produce green sustainable electric energy that can be used to decrease the energy consumption from non-renewable sources and utilizing this energy in street lighting. The study was carried in three bus stations in Alexandria by having measurements during weekdays and weekends in order to study the noise produced in the selected stations and the amount of electric energy that could be produced and utilized in street lighting. The noise level index LDEN was calculated for each of the three selected locations. The equivalent noise level values were always exceeding the limits through the day, evening and night. At daytime they ranged between 75-85 dB which is higher that the permissible limit by 10-20 dB, at evening they ranged from 80-85 dB which is also higher than the permissible limit with 20-25 dB and at the night they ranged from 75-80 dB which is higher by 20-25 dB than the permissible limit. The research concluded that utilizing noise using the piezoelectric material is successful. The electric energy produced from an area of 1.45 m2 containing 690 piezoelectric QB220-503YB transducers at each of the selected stations was about 0.024 watt hr. This amount of electric energy is too small to be used in an application. So the application area should be maximized to hundreds of square meters to produce beneficial electric energy that can be used in lighting 1 LED street lamp or it can be stored and used when needed in applications that use greater amount of electric energy and this would help in reducing the energy consumed

Applicability of fractional slot axial flux permanent magnet synchronous machines in the field weakening region

In this paper, a complete sensitivity analysis of the optimal parameters for the axial flux permanent magnet synchronous machines working in the field weakening region is implemented. Thanks to the presence of a parameterized accurate analytical model, it is possible to obtain all the required parameters of the machine. The two goals of the ideal design are to maximize the power density: Pdensity and the ratio of maximal to rated speed: nmax/nr, which is an inductance related parameter keeping the efficiency at the target speed above 90%. Different slots/poles/phases combinations are studied to reveal the optimum combination for each phase. This paper has studied the effect of the ratio of number of stator slots to number of rotor poles on the Pdensity and nmax/nr. It is shown that a low value of this parameter results in a better Pdensity and nmax/nr. The effect of the outer diameter, and the inner to outer diameter ratio are studied with respect to the two design goals. In addition, a comparison between the finite and the theoretical infinite speed designs is implemented. A complete 3D finite element validation has proven the robustness of the analytical model