Ozgur Ustun

Energy Management Method for solar race car design and application

The Energy Management Method for designing a solar-cell supplied electrical vehicle is described and its implementation on Istanbul Technical University (ITU) race cars is discussed. The effectiveness of the method has been tested and proved during the 2006, 2007 and 2008 races organized by the Scientific and Technical Council of Turkey. The “Energy Management Model (EMS)”, which computes the energy consumption of the virtual vehicle on the virtual race track. For this purpose, electrical and mechanical components of the vehicle are modeled and the energy values are calculated while vehicle computer model is running on three dimensional model of the test track. When the maximum performance scenario, which means maximum possible speed for available energy, is obtained, then brushless dc machine and its driver are designed accordingly. A data acquisition system is formed to measure vehicles electrical and electromechanical quantities. This information is send to the main computer through a wireless communication system. The main computer runs the energy management program and controls whether the race is progressing suitable with the best race scenario. If any discrepancy between simulation and experiment is detected a new optimum scenario is defined and implemented. With this flexible method, maximum performance is achieved by neither flatting the battery in the middle of the race nor remaining partially charged at the finish line.

Design, analysis and implementation of a subfractional slot concentrated winding BLDCM with unequal tooth widths

The paper presents a study on design, analysis and implementation of a sub-fractional slot winding brushless dc motor with unequal tooth widths which is intended to use for light electric vehicle propulsion. Unconventional motor structures are gaining attention because of demands for electric vehicle technology. The main object is to design a BLDC motor having a larger value direct-axis phase inductance which is enabling high performance field weakening operation. For this reason, a subfractional slot concentrated winding structure with unequal tooth widths is chosen. The design phase is including the motivation and the computer aided design works. A software package based on configurator approach is used to determine the motor parameters in a broad sense. Then the motor is modeled in a FEA package for detailed analysis. The designed motor is manufactured precisely and an experimental study is held to verify the design work. The comparison of calculated and experimental results shows that most of the motor parameters can be obtained with a good accuracy.

Design and analysis of a sub-fractional slot concentrated winding BLDCM with unequal tooth widths

The paper presents a study on the design and analysis of a sub-fractional slot concentrated winding brushless direct current motor (BLDCM) with unequal tooth widths for a light electric vehicle application. This kind of brushless surface permanent magnet (SPM) motor is equipped with easy-to-manufacture features which are crucial for the electrical machinery market, especially for electric motors used in electric vehicles. The structure also responds quite effectively to field weakening operation, because of its inherent higher inductance value. The study is focused on increasing the winding inductance value by using the designs analysed in magnetic analysis software. A selected BLDC motor structure is manufactured and tested to verify the design.

Sensorless Control of Brushless DC Motor Based on Wavelet Theory

Abstract This article seeks to develop a sensorless drive technique for brushless machines based on wavelet theory that provides the advantages of separating low-frequency and commutation effects. The approach adopts two methods of position prediction. The first method employs self-inductance variation, as established with finite element analysis. The second is based on induced voltage and zero-crossing point estimation. The problem of starting is resolved by sensing inductance for the first method and by providing a look-up table for each direction of rotation for the second method. Both proportional-integral-derivative and fuzzy control algorithms are developed, and simulated current and speed-controlled performance predictions are obtained. Daubechies discrete wavelet analyses of experimental and simulated waveforms are obtained, with emphasis on commutation intervals. An algorithm is developed to predict commutation instants from wavelet results. The simulation model and its wavelet analysis match the experiments.

Dynamics and limits of electrical braking

Conversion between electrical energy and mechanical energy is done by electrical machines. It is possible to use most of the electrical machines as motor or generator and also it is easy to switch between these states. This phenomenon makes them preferable in any dynamic application. Due to fast torque response, ease of control and efficiency; brushless DC machines (BLDC) are widely used in applications those need both acceleration and deceleration in operation, i.e. electric propulsion. This paper investigates features and scope of using a BLDC as a motor/generator.

A study on autonomous vehicle development process at Okan University

In this paper, the development process of an autonomous vehicle is explained, and the project development stages are summarized. The vehicle is designed to go on urban roads, autonomously. This project has been implemented at The Transportation Technologies and Intelligent Automotive Systems, Application and Research Center (TTIS) which is established within the Faculty of Engineering and Architecture at Okan University. The project has been planned to be developed in three stages. In the first development stage, majority of the vehicle mechatronics parts are completed and the autonomous drive is achieved by using the LIDAR. To achieve the autonomous operation, steering, throttle and braking systems are controlled electronically. The first two development stages were completed on March 2012. In the third development stage, the integration of GPS and other necessary sensors will be mounted to the vehicle and the autonomous operation of the vehicle will be accomplished under normal traffic conditions.

Design of a position controlled electric actuator used in fluid control valves

Valves are the main elements for controlling fluids in industry and other application areas. To control flow precisely, valves need a controlled action which leads to implement actuators, gear systems and electronic controllers. Increasing dominance of electrical actuators due to the advantages of easy control and intervention and space-efficient designs brings seldom implementation of hydraulic and pneumatic actuation. In fluid control applications, the main target is to obtain the right position, i.e. angle for rotary actuators, for adjusting flow rate. In this study, the design and implementation of a position controlled electrically actuated valve used for fluid control are presented. The design phases of system universal power supply and electronic control system are given and the experimental results of position control which are representing the validation the design study is also discussed. Also a special current control scheme is used to overcome transient disruptions.

Development of high efficiency multi-output flyback converter for industrial applications

This study presents the development processes of a high-efficiency two-output flyback-converter. The detailed design phases are presented together with encountered design obstacles, limitations and the methods to overcome them. Despite their widely use in industry, studies on high-efficient flyback converter design still remains a need. Most of the flyback converters are designed with multi outputs for their various input voltages. This study firstly describes the preliminary design stages, modeling studies and definition of magnetic and electronic components and PCB design processes followed by a prototype manufacturing. Modelling study is conducted in MATLAB/Simulink environment, and PCB design is realized in Altium Designer Software. Prototype is tested and its performance parameters are recorded. It is seen that the performance values are good agreement with those of design objectives.

Comparison of different line start interior permanent magnet synchronous motor types with respect to IE4 efficiency class

Recently, the increasing requirements and tendencies of higher efficiency systems have caused a substantial impact on electric motor design. Designers tend to change their views on motor topologies to provide the predetermined values of higher efficiency classes (such as IE3, IE4, IE5). Line-start interior permanent magnet synchronous motors (LSIPMSM) are strong candidates for higher efficiency class general purpose motors due to their higher MTPA (maximum torque per ampere) values. In this study, three different rotor types of LSIPMSM, i.e. V-magnet type, spoke-magnet type and rectangular-magnet type, are investigated with regard to efficiency requirements of super premium efficiency class (IE4). The impact of designs on rotor cage which is essential for starting and synchronization is also studied. The electromagnetic design study is conducted and then the optimized designs are manufactured and tested. The most applicable motor type is determined by means of its ease-of-manufacture and low cost features.

An approach to optimal design of double-sided coreless linear motor

Double-sided coreless linear motors have a crucial role in direct-driven precise linear motion applications. In this study, an optimum design effort focused on thrust force production is presented. For an applicable brushless linear motor structure, winding and permanent magnet (PM) dimensions which are providing the highest possible force are defined by using finite element analysis (FEA). It is shown that the most important problem of an optimum design is arising from placing proper amount of ampere-turns, i.e. windings, without losing a substantial value of permanent magnet flux density due to increased air gap. For obtaining an optimal design, structural demagnetization, loading demagnetization and fringing flux must be taken into account. So a trade-off is provided between the winding structure and the PM assembly.