The bio-inspired algorithms are novel, modern, and efficient tools for the design of electrical machines. However, from the mathematical point of view, these problems belong to the most general branch of non-linear optimization problems, where these tools cannot guarantee that a global minimum is found. The numerical cost and the accuracy of these algorithms depend on the initialization of their internal parameters, which may themselves be the subject of parameter tuning according to the application. In practice, these optimization problems are even more challenging, because engineers are looking for robust designs, which are not sensitive to the tolerances and the manufacturing uncertainties. These criteria further increase these computationally expensive problems due to the additional evaluations of the goal function. The goal of this paper is to give an overview of the widely used optimization techniques in electrical machinery and to summarize the challenges and open problems in the applications of the robust design optimization and the prospects in the case of the newly emerging technologies.

The installed solar capacity in the European Union has expanded rapidly in recent years. The production of these plants is stochastic and highly dependent on the weather. However, many factors should be considered together to estimate the expected output according to the weather forecast so that these new PV plants can operate at maximum capacity. Plants must be operated in coordination with maintenance operations and considering actual energy market prices. Various methods have recently been developed in the literature, ranging from the most impactful artificial-intelligence-based generation estimation methods to various diagnostic and maintenance methods. Moreover, the optimal operational and maintenance strategy usually depends on market regulation, and there are many concerns related to the distribution system operator. This review article aims to summarize and illustrate the challenges of operating and maintaining solar power plants and the economic and technical importance of these problems.

Inductive fault current limiters, such as saturated cores topology, have been considered as an enabling technology for the advent of modern power grids. Thereby, several full-scale prototypes have been developed in recent years aiming, e.g., supporting increased penetration of dispersed generation, mostly from renewable sources. For the advent of these devices and technology, the development of straightforward design tools that allow simulating them in electrical power grids with different voltage ratings and characteristics is required. In this paper, a methodology for simulating the behavior of saturated cores limiters is presented as an alternative to techniques based on finite elements methods (FEM), thereby dramatically reducing computation time. This methodology is based on characteristic parameters of those limiters and is compared with FEM simulations. Experimental measurements in a laboratory scale prototype are also carried out to validate the proposed methodology.

Maritime ports represent an important ecosystem for pollutant emissions and, considering the ongoing energy transition, need to adopt new solutions to mitigate current emission levels. These emissions are partially avoidable if ships and vessels docked at the port use electric energy to feed their power needs instead of using their internal combustion engines. In Europe, there is an ongoing discussion on including such emissions in the European Union Emissions Trading System, which will represent added costs for maritime operators. Onshore power supply systems can contribute to the ongoing energy transition by allowing the use of electric power to feed docked ships. As a first step to contribute to the development of onshore power supply solutions, it is necessary to evaluate the added power needs that these systems would represent for the port. This paper presents a methodology that allows port operators to verify, straightforwardly and transparently, their power needs for onshore power supply applications. The methodology is based on the historical data of docked ships at the port or quay level and provides an energy analysis of each type of vessel to determine the power to be installed at the port so that it is possible to supply energy to different types of ships and vessels simultaneously. Additionally, the implemented methodology provides economic and technical decision support factors by comparing the fuel costs with electric power costs, assessing the potential for this transition to onshore power supply. The methodology is validated using a real case study for the Port of Lisbon, and obtained results demonstrate the potential for the installation of an onshore power supply in medium- to large-dimension maritime ports.

Magnetic shielding inductive fault current limiters with high temperature superconducting cylinders have previously been described by a characteristic (or maximum) hysteresis loop, built from properties of their constitutive parts, which allowed predicting their behavior in electrical grids. These preliminary results were based on finite element simulations, but posterior experiments suggested limitations in the models. In order to investigate the application of these previous models to real devices, two laboratory-scale prototypes were built with different types of superconducting material in the secondary, either bulk cylinder or tape. Although the behavior of both devices is still approximately defined by a maximum hysteresis loop, differences in the shielding current response, when compared with previous model, must be incorporated in future models.

Inductive superconducting fault current limiters have already demonstrated their technical viability in electrical networks. Its architecture and robustness make them potentially adequate for distribution networks, and this type of devices is considered as an enabling technology for the advent of embedded generation with renewable energy sources. In order to promote the growth and maturity of these superconducting technologies, fast design tools must be developed, allowing simulating devices with different materials in grids with diverse characteristics. This work presents advances in the development of such tool, which, at present stage, is an effective alternative to software simulations by finite elements methods, reducing dramatically computation time. The algorithms are now compared with experimental results from a laboratory scale prototype, showing the need to refine them