In this article, the parameter identification of a brushless DC motor (BLDC) is presented. The approach here presented is based on a direct identification considering a three-phase line-to-line voltage electromagnetic torque as function of the electric currents and rotor speed. The estimation is divided into two stages. First, the electrical parameters are estimated by well-known no-load and DC tests. Consequently, estimation of mechanical parameters is performed using a recursive Least Square Algorithm. The proposed approach is validated by comparing model responses to motor real time responses. Additionally, the design, digital simulation and real time implementation of a PI rotor speed controller, based on the estimated model, validate the identification proposal presented here.

A strong circuit-field coupling technique that can analyze multiple magnetic field systems (2D Cartesian and axisymmetric) is adapted to study power transformers. The technique is based on finite-element (FE) and modified nodal analyzes, leading to a multi-field system approach than can effectively take account of the 3D magnetic field existing inside and outside the transformer core. Hence, cumbersome 3D FE simulations are circumvented, overcoming high computational costs. A 2D Cartesian FE model is set up to represent the cross-section of the transformer core and its three-phase winding, whereas an axisymmetric representation is employed for the end sections of each set of windings (one per phase). All models and their associated circuit systems are simultaneously solved, providing a circuit-field method that is easy to implement at low computational cost, keeping the well-known advantages of 2D FE modeling. Electrical currents and local values of magnetic flux density are calculated for two limiting conditions: rated-load and short-circuit operation. Our approach shows a remarkable small difference (no higher than 1%) with a full 3D FE model.

The present work proposes a nonlinear model of a buck–boost DC-DC power converter considering the nonlinear magnetic characteristics of the power inductor and electrical losses of the system. The Euler–Lagrange formalism is used for formulating the proposed model. Previous research works have reported mathematical models to describe power inductor dynamics. However, a gap in the literature remains regarding modeling this kind of element when it operates within power converters. Also, a linear-based controller scheme is proposed to regulate a non-ideal buck–boost DC-DC power converter. A methodology for tuning the proposed controller is presented, which considers the nonlinear model structure of the power converter, the linearization procedure based on an identification process, and a frequency domain analysis based on the approximated linear model. Finally, the tuned control scheme is tested on the nonlinear model of the power converter under several operational conditions showing excellent performance by effectively regulating the output voltage. The results are compared with those derived from alternative control strategies, and a better performance is generally obtained.

Eddy currents are an electromagnetic phenomenon that represent an inexhaustible source of inspiration for technological innovations in the 21st century. Throughout history, these currents have been a subject of research and technological development in multiple fields. This article delves into the fascinating world of eddy currents, revealing their physical foundations and highlighting their impact on a wide range of applications, ranging from non-destructive evaluation of materials to levitation phenomena, as well as their influence on fields as diverse as medicine, the automotive industry, and aerospace. The nature of eddy currents has stimulated the imaginations of scientists and engineers, driving the creation of revolutionary technologies that are transforming our society. As we progress through this article, we will cover the main aspects of eddy currents, their practical applications, and challenges for future works.

Induction stoves are increasingly recognized as the future of cooking technology due to their numerous benefits, including enhanced energy efficiency, improved safety, and precise cooking control. This paper provides a comprehensive review of the key technological advancements in induction stoves, while also examining the societal and health impacts that need to be addressed to support their widespread adoption. Induction stoves operate based on the principle of eddy currents induced in metal cookware, which generate heat directly within the pot, reducing cooking times and increasing energy efficiency compared with conventional gas and electric stoves. Moreover, induction stoves are considered an environmentally sustainable option, as they contribute to improvements in indoor air quality by reducing emissions associated with fuel combustion during cooking. However, ongoing research is essential to ensure the safe and effective use of this technology on a broader scale.

At present it is claimed that all electrical energy systems operate with high values of efficiency and reliability. In electric power systems (EPS), electrical power and distribution transformers are responsible for transferring the electrical energy from power stations up to the load centers. Consequently, it is mandatory to design transformers that possess the highest efficiency and reliability possible. Considerable power losses and hotspots may exist in the bushing region of a transformer, where conductors pass through the tank. Most transformer tanks are made of low-carbon steel, for economical reasons, causing the induction of high eddy currents in the bushing regions. Using a non-magnetic insert in the transformer tank can reduce the eddy currents in the region and as a consequence avoid overheating. In this work, analytical formulations were developed to calculate the magnetic field distribution and the stray losses in the transformer region where bushings are mounted, considering a stainless steel insert (SSI) in the transformer tank. Previously, this problem had only been tackled with numerical models. Several cases were analyzed considering different non-magnetic insert sizes. Additionally, a numerical study using a two dimensional (2D) finite element (FE) axisymmetric model was carried out in order to validate the analytical results. The solved cases show a great concordance between models, obtaining relative errors between the solutions of less than two percent.