Nowadays the economic analysis of an induction motor’s life cycle is the clearest way to measure the viability of actions to promote energy-efficient technologies to the end user. The cost effectiveness in motors replacement by energy-efficient motors is a well-known practice that leads to energy savings, however this paper presents the cost-effectiveness of low-power induction motors which have their efficiency improved after rewinding. This process improves the investment viability and brings the greatest financial and energetic savings. In this paper, low-power induction motors are rewound and their efficiencies are measured by tests A and B from IEEE standard 112/2017. The rewound motors have better cost-effectiveness than replacement by IE3/Premium and even IE4/Super-Premium units. The rewound motors increase between 3 and 4 percentage points in relation to former efficiency and the payback is less than 2 years, regardless of the efficiency measurement method.

The permanent magnet (PM) spherical motor has been subject to growing interest from the scientific community due to its potential for applications in distinct areas, particularly in robotics, prosthetics, satellite control, sensors or camera systems. Motivated by this movement, the current work presents all the steps for the efficient design and construction of a spherical motor model, using compound deposition technology with the aid of a 3D printer. Furthermore, we report comprehensive studies on the accuracy of the positioning system of the proposed motor using only three stator coils, which jointly act to move the rotor axis toward any point in the hemisphere. Unmodeled nonlinear phenomena, such as friction, impair accurate positioning of the motor actuator, but this is solved by means of a visual servo control system, which allows the user to collect input–output data to train an artificial neural network model. Details on the construction of the proposed motor are reported, in addition to the numerical results of the positioning control in tracking a desired trajectory.

This paper proposes a robust control based on generalized predictive control (GPC) applied to the current control loop for a switched reluctance motor (SRM) drive. The proposed controller has two degrees of freedom where the setpoint tracking is decoupled from the load disturbance rejection at the nominal case. In addition a filter design is proposed in order to achieve good relationship among robustness, load disturbance rejection, and noise attenuation. Simulation and real experimental results are shown to illustrate the controller performance.

This work looks at a conception of a roped elevator prototype, using a linear induction motor (LIM) as traction machine and hence a development of a linear drive. Thus the development of a specific inverter to feeding the linear motor, allows several ways to drive the elevator, through a suitable choice of the RMS voltage levels, an angular phase displacement and a fundamental frequency of the output voltage. As result tries to establish a new paradigm of the vertical conveying, through a new construction technique and arrangement of the system with counterweight allowing an increase of trustworthy, comfort and costless.

Squirrel-cage induction motors (SCIMs) manufactured before adoption IE1 class or even after, which have been in operation for a minimum of 10 years within the industry, are being replaced with brand-new ones with higher efficiency classes such as IE3, or IE4 to comply with minimum energy performance standards (MEPS) adopted in most countries. This transition has been established as a profitable energy efficiency action (EEA), notwithstanding the elevated acquisition costs associated with such high-efficiency motors (IE3/IE4). When looking for new EEAs, optimized rewinding of oversized, line-operated, fixed-speed SCIMs of IE1, or IE2 class shows up as a cheaper option with excellent cost-effectiveness. It allows for upgrading the efficiency class to IE3 or IE4, as well as increasing the efficiency at loads lower than 50%, potentially leading to a reduction of the consumption of electrical energy. This paper shows how to upgrade the motor efficiency class through optimized rewinding and presents an economic framework based on the life cycle cost analysis (LCCA). Theoretical and experimental results show that rewinding a SCIM with a specific optimized winding configuration can increase its efficiency and be a cost-effective retrofitting measure compared to replacing the motor with a brand-new IE3 or IE4 class counterpart. In case studies conducted in the Portuguese industry, fixed-speed, variable-torque motors were rewound using an optimized rewinding strategy, leading to a significant reduction in both active and reactive power input. This approach also exhibited a superior cost-benefit ratio compared to replacing the motor with a brand-new one of IE3 or IE4 class.

This paper presents an analysis of the influence of the switched reluctance machine design parameters on its steady-state operation characteristics (phase inductance, phase current and mechanical output torque). The present analysis is carried out using computational simulation, based on the constructive parameters of a SRM designed by the authors. It is also suggested applications for incoming studies.