Search

Induction motors, particularly single‐phase induction motors (SPIMs), represent the major consumption of power in the household sector. SPIMs that fail during their life cycle represent the best opportunity to improve their efficiency by replacing or repairing them. Although replacing faulty motors with new and efficient ones results in significant energy savings, this replacement is uneconomical due to its high initial costs. Additionally, this option requires extensive energy and materials to manufacture, resulting in a considerable environmental impact. This article aims to introduce a three‐phase rewinding of a failed SPIM using a rewinding algorithm that significantly improves the machine's efficiency and performance in an economically viable way. The 0.75 HP single‐phase capacitor‐start induction motor has been rewound to convert it into a three‐phase motor with the required 110 V line voltage and 50 Hz frequency. The economic analysis implies that the rewound machine's life‐cycle cost is 6% and 18% lower than the purchased SPIM IE1 and existing SPIM by below efficiency class respectively. The rewound motor achieves a payback period of 1–1.6 years for different motor loading levels, based on the world average electricity price, indicating an economically viable solution. [ABSTRACT FROM AUTHOR]

Here, the authors present a new constrained multi‐objective optimization method for maximizing output power and efficiency of switched reluctance motor (SRM). The constraints play a significant role in this process. Artificial neural network‐based models are created to represent the SRM behaviour which is a difficult task. For this reason, a single neural network for each objective is built and the number of training data has been increased to reach a good accuracy. The authors propose a neural network‐based adjoint Lp metric technique to combine several objective functions and constraints with different weight factors to a single function which should be minimized. To apply the constraints, an adjoint term is added to the original Lp function including only objective functions. The flux densities of the magnetic materials are selected as the optimization constraints. When approaching as close as possible to the saturation level, the SRM has a better performance. Adding an adjoint term to the original Lp leads to better optimization results which were proved by comparing with a conventional optimization. Also, all obtained results were finally validated by the Ansoft Maxwell software. [ABSTRACT FROM AUTHOR]

The results of numerical and experimental analysis of passive magnetic bearings are presented. The proposed structure is composed of three radially stacked ring‐shaped permanent magnets. The improvements of stiffness and load capacity are proven in comparison to the classical passive magnetic bearing composed of two rings. A preliminary sensitivity analysis is carried out by means of the 2‐dimensional finite element method (FEM) modelling, which is used to provide the initial points for the stochastic optimisation and also to define the best fitness and penalty functions. Finally, the 2‐dimensional FEM is used to compare the force density and the cost of the proposed structure to those of the classical passive magnetic bearing composed of two rings. The optimised structure was manufactured and validated by experimental measurements. The proposed passive magnetic bearing exerts greater axial force and stiffness than similar structures. [ABSTRACT FROM AUTHOR]

The present study investigated the design, simulation, and manufacturing of a new coreless stator axial‐flux permanent‐magnet motor. In addition, to magnets with magnetisation along the motor axis, the new structure included magnets that were magnetised circumferentially and buried at the rotor surface. The electromagnetic design of the conventional axial‐flux motor and the new motor was evaluated according to nominal values and design equations. In this regard, the number of poles and coils, as well as the outer diameter of both motors were assumed to be identical. It was observed that the axial length of the new motor is shorter than the conventional axial‐flux motor. Simulations were continued through comparing the motors in terms of air‐gap flux density, torque, and back electromotive force using the transient finite element method. A comparison of the results showed that the new motor had a better performance than the conventional axial‐flux motor. Subsequently, the new motor was manufactured and tested; the experimental results proved to be close to those presented in the analytical section. [ABSTRACT FROM AUTHOR]