1. Procedure for the determination of the appropriate protective foil size to reduce step voltage using a FEM model and evolutionary methodsMarko Jesenik, Peter Kitak, Robert Maruša, Janez Ribič, 2025, izvirni znanstveni članek Opis: When a fault occurs in a power transmission system, voltages that are dangerous to people may occur. The aim of this work is to present the following method of protection: the use of protective foil installed at the appropriate depth around the transmission pole. Moreover, a procedure is presented for determining the optimal size of the protective film using a minimum number of finite element method calculations. In addition to the finite element method, evolutionary methods are used to determine the appropriate coefficients. Real earthing system data, earth data, and the fault current are obtained from the Slovenian system operator (ELES, d.o.o.) and used exclusively in the presented analyses. The results of determining the appropriate size of the protective foil for two transmission poles are presented, and the determination of the required breakthrough strength of the materials used is shown. The suitability of the proposed method is confirmed. This method is practical and useful when protection with protective foil is required, ensuring only as much as necessary is applied.
Ključne besede: transmission system, touch voltage, touch voltage, step voltage, grounding system, differential evolution, artificial bee colony, teaching–learning-based optimization
Objavljeno v DKUM: 23.04.2025; Ogledov: 0; Prenosov: 1
 Celotno besedilo (29,51 MB) |
2. The approach of using a horizontally layered soil model for inhomogeneous soil, by taking into account the deeper layers of the soil, and determining the model’s parameters using evolutionary methodsMarko Jesenik, Mislav Trbušić, 2025, izvirni znanstveni članek Opis: A new approach using a horizontally layered analytical soil model for inhomogeneous soil is presented. The presented approach also considers deeper soil layers, which is not the case when simply dividing the area of interest into smaller subareas. The finite element method model was used to prepare test data because, in such a case, the soil parameters are known. Six lines simulating Wenner’s method were used, and their results were combined appropriately to determine the soil parameters of nine subareas. To determine the soil parameters in the scope of each subarea, different optimization methods were used and compared to each other. The results were analyzed, and Artificial Bee Colony was selected as the most appropriate method among those tested. Additionally, the convergence of the methods was analyzed, and Memory Assistance is presented, with the aim of shortening the calculation time. In this study, three-, four-, five-, and six-layered soil models were tested, and it is concluded that the three-layered model is most appropriate. A finite element method model based on the soil determination results was constructed to verify the results. The results of the Wenner’s method simulation in the cases of the test data and final model were compared to confirm the accuracy of the presented method
Ključne besede: grounding system, soil model, finite element method, differential evolution, artificial bee colony, teaching–learning-based optimization
Objavljeno v DKUM: 21.02.2025; Ogledov: 0; Prenosov: 3
Celotno besedilo (6,81 MB) |
3. Innovative approach for the determination of a DC motor’s and drive’s parameters using evolutionary methods and different measured current and angular speed responsesMarko Jesenik, Miha Ravber, Mislav Trbušić, 2024, izvirni znanstveni članek Opis: The determination is presented of seven parameters of a DC motor’s drive. The determination was based on a comparison between the measured and simulated current and speed responses. For the parameters’ determination, different evolutionary methods were used and compared to each other. The mathematical model presenting the DC drives model was written using two coupled differential equations, which were solved using the Runge–Kutta first-, second-, third- and fourth-order methods. The approach allows determining the parameters of controlled drives in such a way that the controller is taken into account with the measured voltage. Between the tested evolutionary methods, which were Differential Evolution with three strategies, Teaching-Learning Based Optimization and Artificial Bee Colony, the Differential Evolution (DE/rand/1/exp) can be suggested as the most appropriate for the presented problem. Measurements with different sampling times were used, and it was found out that at least some measuring points should be at the speed-up interval. Different lengths of the measured signal were tested, and it is sufficient to use a signal consisting of the drive’s acceleration and a short part of the stationary operation. The analysis showed that the procedure has good repeatability. The biggest deviation of calculated parameters considering 10 repeated measurements was 6% in case of the La calculation. The deviations of all the other parameters’ calculations were less than 2%.
Ključne besede: differential evolution, artificial bee colony, teaching-learning based optimization, DC motors, electric drive
Objavljeno v DKUM: 26.01.2024; Ogledov: 230; Prenosov: 26
Celotno besedilo (5,41 MB)
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