Browsing by Author "Ozturk,S.B."

Now showing 1 - 8 of 8

Citation Count: 5
Design and Analysis of 240 Watt SEPIC Converter for LED Applications
(Institute of Electrical and Electronics Engineers Inc., 2019) Hayirli,I.H.; Kelleci,B.; Kivanc,O.C.; Ozturk,S.B.; Tuncay,R.N.; Citci,M.O.
A 240 Watt output power SEPIC converter with an output voltage of 24 V is proposed to be used in automotive and railway LED applications. The input voltage of the converter varies between 16 V and 36 V. The stability of the converter is guaranteed by moving one of the dominant pole to lower frequency and canceling the other pole with a zero. The phase margin is higher than 56° across all input voltage values. The transients of the switch is damped using a passive snubber circuit. Electromagnetic analyses are performed using Ansys SiWave™ to determine voltage drop, current distribution, near and far field and resonance behavior of SEPIC converter. Measurement results indicate that the SEPIC converter is stable under various operating conditions. © 2019 IEEE.
Citation Count: 1
Design of a Controller for Torsional Vibrations of an Electric Vehicle Powertrain
(Institute of Electrical and Electronics Engineers Inc., 2019) Karamuk,M.; Ozturk,S.B.
Electric powertrains are subject to vibrations due to weak damping and fast torque response of electric motor. In this study, a PD controller is developed to damp the vibrations. By using PD controller, two solution methods are developed. First solution is to use the wheel speed sensors available in all four wheels. Second solution is to use a reduced order observer to estimate the wheel speed. Differentiation of motor speed and wheel speed is input to the PD controller. Output of the PD controller is the torque damping feedback to the torque reference. Simulation model is developed including a flux vector controlled permanent magnet synchronous motor, powertrain model and vibration controller. The results demonstrate the validity and effectiveness of the proposed scheme. © 2019 IEEE.
Citation Count: 2
Electro-hydraulic power steering system modelling for parameter fault detection based on model reference adaptive frame
(IEEE Computer Society, 2016) Kivanc,O.C.; Ozturk,S.B.; Tuncay,R.N.; Kesici,E.; Yazi,C.
A simple and efficient fault detection and parameter monitoring algorithm for electro-hydraulic power steering (EHPS) system is proposed using model reference adaptive system (MRAS) without any additional sensor. In a faulty situation where the hydraulic system is disabled, assisted power is provided by an electric motor. Therefore, in low speed maneuvers, during sudden direction changes and parking, some parameters of an electric motor in EHPS are affected. These changes threaten the vehicle's driving reliability and performance of EHPS. In this study, an EHPS system with rotor flux estimation based adaptive driver torque control principle has been presented. The motor winding temperature is obtained for monitoring purpose with the help of MRAS stator resistance estimation. The proposed parameter estimation method for EHPS has been simulated by using AMESim and MATLAB/Simulink cosimulation model. Simulation results demonstrate the feasibility and effectiveness of the proposed method. © 2016 IEEE.
Citation Count: 3
An encoder fault tolerant FPGA based robot control using bluetooth of a smart phone
(Institute of Electrical and Electronics Engineers Inc., 2017) Majeed,A.; Ozturk,S.B.; Tureli,D.K.
An FPGA based Bluetooth controlled robot with encoder fault tolerant algorithm is presented. The smart phone is used to obtain user intentions, such as turning, speeding or braking and this data is sent to a robot using Bluetooth. The motor control algorithms and robot communication interfaces are implemented on FPGA for parallel processing. The robot is capable of changing its position with the help of two independent PI closed loop speed controlled DC motors. The motor speed is determined by the accelerometer of the sensor data of a smart phone. The FPGA receives speed information and generates appropriate PWM signals. Motor rpm is calculated via rotary encoder. In case of an encoder failure, an on-board gyroscope helps maintaining normal operation. An Android based smart phone application has been developed. MATLAB is used for simulating an encoder failure and observation of results. The motor control algorithm has been implemented using Verilog and tested on the field. © 2017 EMO (Turkish Chamber of Electrical Enginners).
Citation Count: 0
Exciting system selection for brushless synchronous machine
(2012) Ustun,O.; Ozturk,S.B.; Kivanc,O.C.; Ali Zade,P.G.; Tuncay,R.N.
The paper deals with the special brushless synchronous electrical machine (SBSM) working with an extensive variable load. It's exciting systems usually keep cosθ ≈ 1. Among them are unmanned deep-well oil pumps drives, wind renewable energy SBSM, etc. The SBSMs usually works in harsh climate conditions, where thyristor or IGBT exciting systems are not reliable (except diodes). Oil field drives are supposed to have fire/explosion-proof brushless motors. It is shown in this paper that replacement of induction motors (IMs) with the special brushless synchronous motors (SBSM) with stable cosθ ≈ 1 in the sucker-rod pumps (SRPs) will help to cut energy losses and diminish voltage pulsations in the oil field electric network. It also results in some reduction of oversize motor utilizations. The main proposal of this paper is to avoid any controlled electronic exciting system, but at the same time obtain the stabilizing cosθ ≈ 1 effect by application of the special small construction change in the motor.
Citation Count: 0
MATLAB function based approach to FOC of PMSM drive
(UK Simulation Society, 2016) Kivanc,O.C.; Ozturk,S.B.
In this study, modeling and simulation of a speed sensor driven field-oriented control (FOC) of a permanent magnet synchronous motor (PMSM) drive is developed by using MATLAB Function blocks in MATLAB/Simulink. This method allows easier algorithm and software development stages for experimental studies compared to the classical block diagram approach. The superiority of the method over commonly used “Code Generation” tools is also emphasized. First, a MATLAB/Simulink model of the FOC of PMSM drive is developed by using MATLAB programming in MATLAB Functions similar to C coding techniques. The results of the simulation are presented. Then, the MATLAB programming based codes developed in simulation are implemented in a TMS320F28335 floating-point MCU by using C programming language and the experimental results are obtained. Finally, the results of the simulation and experiments are compared. © 2016, UK Simulation Society. All rights reserved.
Citation Count: 9
Sector determination for SVPWM based four-switch three-phase VSI
(John Wiley and Sons Inc, 2017) Kivanc,O.C.; Ozturk,S.B.
Sector determination for a normalised space vector pulse width modulation (SVPWM) scheme is proposed for four-switch three-phase (FSTP) voltage source inverter (VSI) by using already available stationary reference frame stator voltages without requiring complex trigonometric calculations. The proposed method has been simulated by using MATLAB/Simulink and implemented using a VSI with a TMS320F28335 floating-point digital signal processing. Simulation and experimental results show the feasibility and effectiveness of the proposed SVPWM algorithm for FSTP inverter. © The Institution of Engineering and Technology 2017.
Citation Count: 6
A simple least squares approach for low speed performance analysis of indirect FOC induction motor drive using low-resolution position sensor
(Institute of Electrical and Electronics Engineers Inc., 2017) Ozturk,S.B.; Kivanc,O.C.; Atila,B.; Rehman,S.U.; Akin,B.; Toliyat,H.A.
This paper investigates an ordinary least squares based indirect field oriented control (IFOC) of induction motor at very low speed range (1-5 rpm) using a low-count encoder. At very low speeds the speed estimation provided by common techniques for low-count encoder applications such as averaging the last two speed samples and/or considering the previous speed value until the next position update can generate erroneous speed results which can cause instability in the overall control system. By proposing ordinary least squares (OLS) method with low-resolution position sensor based speed estimation for IFOC of IM drives more realistic speed can be obtained by fitting the predefined sets of speed data in a linear or quadratic manner. Experimental tests prove that the proposed scheme which is constituted of OLS (linear) speed estimation algorithm increases stability and improves low and oscillating speed performance of IFOC of IM drive with low-count encoders down to four pulses per revolution. © 2017 IEEE.