The most often used motor in commercial drives is the induction motor. While the induction motor is operating, electrical, thermal, mechanical, magnetic, and environmental stresses can result in defects. Therefore, many researchers who are involved in condition monitoring have been interested in the development of reliable and efficient fault diagnostic technologies. This paper’s goal is to provide an overview of available fault detection methods for the broken rotor bar problem, one of several defects associated to induction motors. Despite the fact that it is less common than bearing or insulator failure, this fault may cause electrical machines to fail catastrophically. It can be quite harmful, especially in large motors, and it can develop as a result of manufacturing faults, repeated starting of the machine, mechanical stress, and thermal stress. Hence, a review on rotor defect diagnosis was conducted. In order to confirm rotor bar fracture, this research provides probable defect signatures that can be extracted from the current signal. Each defect signature is reported according to (a) loading level, (b) the number of BRBs, (c) validation, and (d) methodologies.

Renewable energy includes a wide variety of technologies that may provide electric energy without releasing greenhouse gases. However, due to the intermittent nature of renewable energy sources, relying on a single source cannot ensure a steady energy supply, making it essential to combine multiple renewable energies with thermal generators to meet the required energy demand. Furthermore, the economic feasibility of renewable energy can vary significantly across different geographical regions. These challenges can be addressed successfully through the global electricity grid concept. It enables the efficient transmission of clean energy over long distances, and it allows nations to capitalize on their unique renewable energy strengths, facilitating the seamless exchange of clean energy to meet global demand while optimizing the use of renewable resources worldwide. This paper examines global and regional initiatives aimed at fostering a sustainable energy future, highlighting the benefits and challenges associated with globally interconnected power grids and intercontinental transmission networks. Although the challenges and opportunities of the global electricity grid are well understood, the quantification of its costs, benefits, and environmental impacts remains in its infancy, leaving a significant gap in the current literature.

The impact on the stability of power systems is rising as the penetration level of renewable energy with sporadic natures rises rapidly on the grid. However, the impact of different types of renewable energy sources (wind, solar) and their combination on system stability varies even with the same penetration level. This paper concentrates mainly on the stability analysis of multi-machine systems connected to various types of renewable energy sources. The study presents a simple and novel control technique named automatic reactive power support (ARS) for both single and combinations of renewable sources by injecting the available reactive power into the system during fault through converters to enhance system stability. The permanent magnet synchronous generator (PMSG) and doubly fed induction generator (DFIG) are both considered as wind generators in this paper for comparison. In addition, transient stability enhancement is carried out by improving critical clearing time of a three-phase fault in the power system. With the creation of a 3-phase fault at various buses, stability analysis is carried out on the 9-bus WSCC test bus system and also on the 68-bus IEEE test system. Comparative analysis of six test case conditions is provided and the considered cases are without renewable source, with DFIG as a wind generator, PMSG as a wind generator, solar PV farm, wind farm with DFIG and solar PV in combination and the combination of wind farm with PMSG and solar PV. Moreover, the improvement in critical clearing time of the system is compared using conventional and proposed controls with all the aforementioned renewable sources. Comparative results show that the proposed control technique improves system stability and also that the combination of renewable energy sources ought to enhance the critical clearing time of system.

In this paper, the available methods and procedures for creating equivalents for the analysis of electromagnetic transients in power systems are presented and discussed. General requirements of power system representation during simulation of electromagnetic transients are shown. The main available procedures are shown, along with an assessment of their advantages and disadvantages. Methods to search for the optimal replacement of structures in time and frequency domains are discussed. Optimization and direct methods in the frequency domain are presented. Each of these methods is discussed with respect to their possible use in determining the structure of the equivalent circuit for the study of electromagnetic phenomena. Methods to reduce a complex power system, as one of the approaches to determining the structure and parameters of the equivalent circuit, are also presented. Contraindications to the search for equivalents in the frequency domain to study electromagnetic transients are discussed. An analysis of methods for the identification of parameters of the equivalents is presented. The latest advances in the search for the structure and parameters of equivalents are presented, particularly the use of artificial neural networks in the process of replacing parts of systems. Finally, the analyses conducted in this study, together with recommendations regarding the choice of the procedure during the search for equivalents for the analysis of electromagnetic transient phenomena, are summarized.

Integrating wind power generators, whose frequency varies in a wide range due to varying wind speeds, into a grid is a formidable problem. At present, the use of permanent magnet synchronous generators (PMSG) and doubly fed induction generators (DFIG) as wind generators with suitable control is the best possible solution. However, a dual-field excited synchronous generator (DESG), which has two windings on the rotor, can also be used for the same purpose with appropriate control. A new control strategy, which essentially employs the d-axis and q-axis components of the alternator terminal voltage, is suggested here. This strategy essentially results in exciting the two field windings with a slip frequency. This eventually holds the stator frequency constant, irrespective of the rotor speed of the wind generator. The difference between the required frequency and the natural frequency, analogous to the rotor speed of the wind power generator, is the slip frequency. The ring modulator automatically adjusts the slip frequency depending on the actual speed of the generator’s rotor. This paper uses the ANSYS MAXWELL 2022 R1 software to design a DESG and uses a ring modulator as the control function generator for feedback with ANSYS TWIN BUILDER 2022 R1. Simulations are carried out using transient–transient co-simulation by combining both of these software tools for cases of both a constant-speed input and of a variable-speed input to the rotor of the machine. Moreover, a mathematical model of the DESG as a wind generator with the proposed controlled strategy is used to perform the stability analysis of a nine-bus three-machine system, and the results are compared with those of conventional wind generators.

It is vitally important that a transmission network provides a continuity of electricity to end users and that the transmission system operator prioritizes its safety and reliability. This article presents the possibilities of using multi-track overhead lines with varying levels of rated voltage, run on a common support structure. This solution would ensure safe operation of the system, reduce the area used for the construction of new overhead lines, and, at the same time increase the transmission network capacity. This article focuses on the method of modeling overhead lines for the analysis of electromagnetic transient states that occur during non-simultaneous disturbance phenomena. This article presents the idea of multi-circuit, multi-voltage lines and their validity of use in power systems. An analysis of electromagnetic transient states for non-simultaneous disturbances in multi-path, multi-voltage lines is presented. This analysis has been made on the basis of a network model, using ATP-EMTP (Alternative Transients Program-Electromagnetic Transients Program) software for solutions, for a Polish power system. Particular attention was paid to the most unfavorable phenomena appearing in the modeled system. The impact of the emerging electromagetic transients in multi-path, multi-voltage lines was evaluated. It was shown that the specificity and rapid changeability of the emerging electromagnetic transients and lack of a universal model of the overhead power line make the analyses of electromagnetic transients highly labor-intensive and time-consuming. Each change is connected with the necessity to create new line models for the study of electromagnetic transient states dependent on many factors.