Browsing by Author "Ertan, H. Bulent"

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An Approach for Improving Performance of Sensorless Field Control
(Ieee, 2018) Ertan, H. Bulent; Filci, Tayfun; Electrical-Electronics Engineering; 06. School Of Engineering; 01. Atılım University
Sensorless vector control is preferred in some applications, because there is no need for speed or position sensor. However, by their very nature, they are susceptible to making position error in rotor position estimation. As a consequence the performance of motor drives employing this technology is lower than those which employ sensors. This paper presents a new approach which identifies and uses rotor slot harmonic current component in the stator current to identify rotor position. The time taken by the algorithm used is short enough to be embedded within the vector control algorithm. The essence of the algorithm is treating the current component due to rotor slot harmonics as an amplitude modulated signal on the fundamental current component. The magnitude of this current component is identified via demodulation. Using this information rotor position and speed can be determined. This approach is tested on a commercial induction motor and some results are presented which illustrate that rotor position can be successfully determined.
Citation - WoS: 2
Comparison of a Magnetically Geared Pm Wind Generator With Radial Flux Generator
(Ieee, 2018) Zeinali, Reza; Ertan, H. Bulent; Electrical-Electronics Engineering; 06. School Of Engineering; 01. Atılım University
Direct drive wind turbines promise to be more reliable and efficient than commonly used geared wind turbines. This paper presents part of a study aiming to identify whether "Dual Stator Spoke Array Vernier Permanent Magnet" (DSSAVPM) generators present an advantage, regarding size or cost, as compared to the conventional radial flux PM machine for direct drive applications. For this purpose, design of both machines is optimized for the same specifications and using the same design criteria. Optimization results are presented and discussed. It is found that a DSSVPM generator design, with almost the same performance as the RFPM generator, but with 45% of its mass is possible.
Citation - WoS: 3
Citation - Scopus: 5
Designing High Power Density Induction Motors for Electric Propulsion
(Ieee, 2022) Ertan, H. Bulent; Siddique, M. Salik; Koushan, Salar; Azuaje-Berbeci, Bernardo J.; Electrical-Electronics Engineering; 06. School Of Engineering; 01. Atılım University
Designing high-power-density electric motors for propulsion has become an increasingly important issue in the past few decades. This is not only because electric vehicles are projected to become the main private transportation means in near future, but also because of the ever so important metro and railway transport requirements. Along with these application areas, electric aircraft propulsion is also coming into focus in recent years. Electric motors for traction are required to have high torque density, high efficiency over a wide speed range and are required to be robust. In recent years, permanent magnet (PM) motors became the favorite choice for such applications because of their higher efficiency than other types of motors. Increasing demand for permanent magnets is likely to cause supply problems. Therefore, permanent magnet-free alternative motor types are of much interest. In this paper, the authors present the design of a 125 kW induction motor for railway application. This design has 3-times the power density of a commercial induction motor. The designed motor is manufactured and its test results are used for establishing an accurate finite-element model for the prediction of its performance. This model is used to investigate the effect of magnetic loading choice, slot shape and magnetic material choice on the efficiency of the motor. It is shown that with the same basic dimensions the efficiency of the motor can be increased to 96% which is comparable with a similar size PM motor.
Driving Conditions Leading To Thermal Runaway in Li-Ion Battery EV's
(IEEE, 2024) Ertan, H. Bulent; Azuaje-Berbeci, Bernardo J.; Electrical-Electronics Engineering; 06. School Of Engineering; 01. Atılım University
The adoption of high-energy-density lithium-ion batteries (LIB) as the energy source in electric vehicles (EV) introduces significant safety concerns. Thermal runaway (TR), a self-accelerating rise in battery temperature resulting in catastrophic failure, is a significant safety concern. Cooling system failure within the EV's thermal management system is one of several factors that can trigger TR. Typically, TR is initiated by exceeding a critical temperature threshold under abusive conditions. Understanding the operating conditions that lead to the path of TR is essential for ensuring EV and occupant safety. Recently, a detailed electrochemical-thermal model that incorporates the chemical reactions within the battery until TR is introduced. This paper aims to illustrate how this model can be used to identify the conditions leading to TR under realistic EV driving scenarios. For this purpose, an Advisor/Matlab-based model of a hybrid EV is developed and verified by tests, is used to estimate the current required from the vehicle's battery pack at a given driving condition. This is followed by the prediction of battery thermal response using the mentioned finite-element-analysis-based battery model. Several scenarios are tested in this paper to determine whether TR occurs and to identify the factors contributing to TR. This study aids in comprehending the factors that contribute to TR and the development of preventative measures for battery management system design.
Citation - WoS: 1
Fem-Based Design Modifications and Efficiency Improvements of a Brushed Permanent Magnet Dc Motor
(Ieee, 2017) Tarvirdilu-Asl, Rasul; Zeinali, Reza; Ertan, H. Bulent; Electrical-Electronics Engineering; 06. School Of Engineering; 01. Atılım University
This paper describes design modifications of a brushed permanent magnet DC motor. Test motor is modeled using a Finite Element Method (FEM) based software. Model accuracy is investigated by comparing measurement and simulation results. Reducing material consumption in motor fabrication while the motor develops the desired torque at a higher efficiency is aimed in this paper. Modifications are done in three stages and simulations results are also presented. These results are also compared to simulation results of the test machine.
Citation - WoS: 14
Citation - Scopus: 18
Inductance Measurement Methods for Surface-Mount Permanent Magnet Machines
(Ieee-inst Electrical Electronics Engineers inc, 2023) Ertan, H. Bulent; Sahin, Ilker; Electrical-Electronics Engineering; 06. School Of Engineering; 01. Atılım University
Analytical performance estimation of a permanent magnet (PM) motor requires an accurate equivalent circuit model. In a lumped electrical model of a PM motor, resistance and inductances appear as passive elements, which are used to represent the phase winding resistance, inductance, core loss, etc. There is currently no available standard for parameter measurement of PM motors. In the literature, there are many studies on inductance measurement. However, they are applied to different types of motors. The purpose of this study is to evaluate those different inductance measurement methods, on the same motors, to identify whether they lead to the same result. Also, it was aimed to find out the difficulties involved in the measurement process. This study concentrates on determining the d -axis and q -axis inductances of two different surface-mount PM motors at standstill and under running conditions. The standstill measurement methods evaluated include the "current decay " method and the "dc inductance bridge " method as well as more common methods. The dependence of the inductances on the current magnitude, frequency, and excitation signal waveform is investigated. Measurements with PWM and sinusoidal ac voltage excitation are found to give similar results. The tests indicated that the "current decay " method is prone to measurement errors especially when the phase resistance is low. It is discovered that inductance measurements from standstill tests are independent of frequency for all practical purposes. Next, the same inductances are measured, while the test motors are running. The methods considered include; inductance measurement from no-load test, zero power factor (PF) load test, and unity PF load test; while the machine is in generating mode. Furthermore, a new inductance measurement method is introduced where the measurement is made while the test motor is driven with a vector-controlled drive. Finally, inductance measurement results from different standstill tests and running tests are compared and evaluated.
Citation - WoS: 3
Integration of Offshore Wind Farm Plants To the Power Grid Using an Hvdc Line Transmission
(Ieee, 2019) Berkani, Abderrahmane; Pourkeivannour, Siamak; Negadi, Karim; Boumediene, Bachir; Allaoui, Tayeb; Ertan, H. Bulent; Electrical-Electronics Engineering; 06. School Of Engineering; 01. Atılım University
This paper investigates an integration of Offshore Wind Farm Plants with Power Grid Based on an HVDC line Interconnection. Large offshore wind farms are installed in the North Sea area using modern multi-megawatt wind turbines. The Voltage source converter - high voltage direct current VSC-HVDC is a suitable means of integrating such large and distant offshore Wind Power Plants (WPP) which need long submarine cable transmission to the onshore grid. The offshore network then becomes very different from the conventional grid, in that it is only connected to electronic power converters. A wind farm model with VSC-HVDC connection is developed. This work presents the modeling and simulation of such a system. The dynamic study of system performance under the fluctuations of wind energy and wind speed was studied to demonstrate the effectiveness of the control strategy. The validity of the proposed control technique is verified by Matlab/Simulink. Simulation results presented in this paper confirm the validity and feasibility of the proposed control approach, and can be tested on experimental setup.
Citation - WoS: 2
Magnetically Geared Direct Drive Wind Generator Thermal Analysis
(Ieee, 2017) Zeinali, Reza; Ertan, H. Bulent; Yamali, Cemil; Tarvirdilu-Asl, Rasul; Electrical-Electronics Engineering; 06. School Of Engineering; 01. Atılım University
This paper considers Dual Stator Spoke Array Vernier Permanent Magnet (DSSA-VPM) generator for the direct drive wind-electric energy conversion. The structure of the generator is described. Although how this design is optimized is not discussed, dimensions of the designed generator are given. In electrical machine design thermal performance is naturally of utmost importance. In this paper thermal performance of the design and how its temperature can be kept within the temperature limit imposed by its insulation class and the permanent magnets used is investigated. It is found that when air flow within the generator is not permitted, at rated load condition the generator temperature reaches very high levels. To lower the operating temperature, ventilation holes are introduced to the end plates of the frame. Also some blades are placed on the rotor to help flow of air over the end windings. A model is introduced to calculate the air speed in the region where air flows. Using the calculated air speed a new heat transfer coefficient is determined for the region where air flows. It is found out that with the mentioned modifications to the structure of the generator the designed generator temperature rise can be kept within the value permitted for its insulation class. Therefore, the power density of the design can be safely compared with the power density of other types of designs for direct drive turbines. It is found that DSSA-VPM generator topology offers a clear advantage over other types of generators considered in the literature.
Citation - WoS: 23
Citation - Scopus: 22
A Model for the Prediction of Thermal Runaway in Lithium-Ion Batteries
(Elsevier, 2024) Azuaje-Berbeci, Bernardo J.; Ertan, H. Bulent; Electrical-Electronics Engineering; 06. School Of Engineering; 01. Atılım University
The increasing popularity of electric vehicles is driving research into lithium -ion batteries (LIBs). Thermal runaway (TR) in LIBs is a serious concern for the safe operation of these high-energy-density batteries that is yet to be overcome. A reliable model is needed to predict voltage variation, heat generation, temperature rise, and the process leading to TR of a LIB battery under its operating conditions (charging-discharging). Such a model can be used to design battery packs more resilient to thermal runaway or assess how a battery pack would perform under hazardous conditions. Furthermore, it can be used for generating a warning signal if there is a possibility of the battery going towards TR. This paper presents an approach to solving this problem, which is not currently well addressed in the literature. The approach adopted in this paper is based on a numerical analysis of a multilayered electrochemical-thermal model of LIB. Tuning the parameters of a LIB for accurate results from this numerical model is presented, as well as the details of the approach in the paper. Experiments are performed under several LIBs, and their voltage and surface temperature variations are measured under various operating conditions, including thermal runaway. The results of the experiments are compared with the predictions of the numerical simulations. An excellent agreement is observed with the experimental results, proving the accuracy of the proposed approach. This approach can be configured to give results in a few minutes. The paper also discusses how the developed approach can be used to create a TR warning during operating conditions or to change the mode of operation of a LIB before a hazard occurs.
Citation - WoS: 1
Sizing of Series Hybrid Electric Vehicle With Hybrid Energy Storage System
(Ieee, 2018) Ertan, H. Bulent; Arikan, F. Remzican; Electrical-Electronics Engineering; 06. School Of Engineering; 01. Atılım University
This work is aimed to develop a realistic design procedure for a series hybrid plug in vehicle, with a view to use it in a mathematical design optimization. The purpose of the optimization is minimizing the initial cost, as well as the running costs of the vehicle. Therefore there is a multi-objective design optimization problem in hand. Such problems are very suitable for mathematical optimization, however, accurate and not time consuming design procedure is a must, to obtain meaningful results. This paper introduces such a design procedure. The approach is illustrated on a commercial vehicle simulation model. The accuracy of the model is illustrated by comparing simulation results with vehicle test results.