Çağdaş Hisar

Sliding mode control (SMC) is widely used for permanent magnet synchronous motor (PMSM) drives because of its robustness against disturbances and parameter uncertainties. However, the reaching law still faces a trade-off between fast convergence and chattering suppression. Reaching laws based on the signum function usually provide rapid convergence but induce severe high-frequency oscillations, whereas smooth or exponential modifications may reduce discontinuity at the expense of slower transient response or excessively large control gains. To address these limitations, this paper proposes a novel sine-logarithmic reaching law combined with a power-rate term for PMSM sliding mode control. The proposed structure avoids both the conventional smooth and exponential approximations commonly used in the literature. A theoretical analysis is presented, and the convergence behavior is characterized in terms of practical finite-time stability. The effectiveness of the proposed reaching law is evaluated in MATLAB/Simulink through comparative PMSM simulation studies, including start-up, steady-state, load-disturbance, parameter-variation, and total harmonic distortion (THD) tests against representative reaching laws from the literature. The simulation results indicate that the proposed method provides a favorable trade-off among rapid reaching, chattering attenuation, steady-state accuracy, and harmonic performance. These findings suggest that the proposed reaching law is a competitive alternative for PMSM sliding mode control.

Synchronous reluctance motors (SynRMs) have gained renewed interest as economical, mag-net-free alternatives to permanent magnet and induction machines, particularly for small- and medium-power electric vehicle propulsion systems where cost, efficiency, and sustainability are critical. Their main advantages include simple construction, high reliability, and suitability for sustainable drive systems. However, SynRMs inherently suffer from torque ripple, acoustic noise, and limited power factor, mainly due to the anisotropic nature of their magnetic design. This study presents a fully integrated Multi-Objective Genetic Algorithm (MOGA)–Finite Ele-ment Method (FEM) framework, which simultaneously minimizes torque ripple and maximizes output power by systematically optimizing rotor flux barrier geometry, in contrast to traditional trial-and-error or single-objective optimization methods. The optimization process evaluates key rotor design parameters, including flux barrier angles, widths, and insulation ratios, while explor-ing a wide design space and corresponding objective function values. FEM analysis is employed at each optimization iteration to accurately assess electromagnetic performance and ensure con-vergence toward the optimal solution. The optimized rotor demonstrates a substantial perfor-mance improvement, with the average torque increasing from 13.15 Nm to 19 Nm and the output power rising from 4.13 kW to 6 kW. The power factor is improved from 0.85 to 0.9, indicating enhanced efficiency and reduced reactive current demand. Moreover, torque ripple is quantita-tively reduced from 8.95% to 8.5%, confirming the effectiveness of the proposed optimization strategy. The introduction of barrier fillets further decreases flux density in the tangential ribs, thereby reducing mechanical stress and core losses. These results confirm that systematic opti-mization of flux barrier geometry can significantly enhance SynRM performance without the use of permanent magnets or complex rotor structures, preserving simplicity and cost-effectiveness.

Vehicle suspension system results in a trade-off between the crucial requirements of road holding and ride comfort. To increase the suspension performance and overcome this difficulty, vehicle dynamic systems must be equipped with new technologies and intelligent materials. This paper proposes a fuzzy logic control strategy to enhance ride comfort and road holding dynamics for a half-vehicle active suspension system. The fuzzy logic controller offers a control approach that enables systems with uncertainty and complexity to be managed effectively. Two fuzzy logic controllers for each tire are executed and arranged for the characteristics of the unsprung and sprung masses. The controllers’ inputs are suspension deflection and sprung mass acceleration for each tire. Moreover, actuator force is generated as the controllers’ outputs. Bump road disturbances are applied to each tire for performance evaluation of the controllers. The performance criteria for the suspension system are selected as acceleration and displacement of sprung mass, suspension deflection, and dynamic tire load. These parameters are compared to the passive suspension system and evaluated on ride comfort and road holding. Ride comfort is enhanced by 34% with the active suspension system, including a fuzzy logic controller. Furthermore, road holding is improved by about 13% regarding suspension deflection and dynamic tire load. In conclusion of the simulation, the proposed control approach enhances ride comfort and road-holding dynamics concurrently.

In recent years, studies aiming to use different motor types for traction purpose, such as in electric vehicles, have become increasingly widespread. Among these motor types, permanent magnet assisted synchronous reluctance motor (PMa-SynRM) has become in-creasingly preferred in commercially electric vehicles nowadays. This study addresses the design and control of a PMa-SynRM, also the comparison with the synchronous reluc-tance motor (SynRM). The motor design process is carried out using the finite element method in Ansys-Maxwell environment. A series of a simulation studies is conducted in the MATLAB/Simulink environment for controlling the obtained motor designed in An-sys-Maxwell. The field-oriented control (FOC) approach is chosen for precise speed con-trol. As a result of the simulation studies, it is observed that the designed motor tracks the reference with minimal error under various load conditions within a closed-loop system. Also, this paper investigates how the PM implementation affects the machine perfor-mance comparing to SynRMs. In addition, such a study takes into account that the de-sign of machines involves always several constraints, including geometry, materials, sup-ply limits, and performance constraints.

In this study, a prototype model was designed and implemented for power system failure. A mobile application was developed for notification of faults that may occur in power systems. The line current data was transmitted with Wi-Fi via module on mobile application and so negative impacts of the production sector was eliminated and the ordinary flow of life by minimizing the duration of power outages due to technical failures were prevented. By measuring the current in the prototype, it was possible to determine a short circuit situation, and to warn the operator with the mobile application on the mobile phone, and then to quickly dispatch them to the defective area. Protection in the power system is carried out more healthily with instant data flow with the mobile application