Search

Indirect field-oriented control, direct field-oriented control, and direct torque control are the most widely used instantaneous torque control techniques for the drive system of alternative energy vehicles (AEVs). This paper evaluates three candidate alternating-current machines and investigates the suitability of different control techniques for the drive systems of battery-powered electric vehicles, hybrid electric vehicles, and integrated starter alternators. Accurate flux and torque estimation is the core of any opted control technique for all types of AEV drive systems. Therefore, an accurate closed-loop voltage model flux and torque estimator that is insensitive to stator resistance variation has been designed. This paper also analyzes loss model control and search control (SC) techniques for the drive system's efficiency optimization and proposes an offline SC efficiency optimization technique. Experimental results are presented to demonstrate the performance of the proposed flux and torque estimator and efficiency optimizer. [ABSTRACT FROM PUBLISHER]

This paper proposes an integrated approach for developing the engineering curricula with a specific focus on engineering design. The proposed approach allows a continuous and coherent development of engineering students' design skills throughout the entire undergraduate curriculum. This ongoing design experience is delivered at an involvement and complexity level compatible with the students' study year. In the integrated approach, three different stages are identified: Structured Design Experience, Guided Design Experience, and Open-Ended Design Experience. The objectives, implementation mechanism, and the expected outcomes of each stage are outlined. The proposed methodology systematically develops not only design skills but also teamwork, communication skills, project management, and lifelong learning. The implementation of the proposed approach is demonstrated by presenting courses in the Electronics track which shows the gradual, integrated delivery of structured, guided, and open ended design experiences as students progress from the freshman to the final year of study. As a case study, the delivery of design skills using the proposed approach is assessed through the students' survey in the electrical engineering curriculum at the American University of Sharjah, United Arab Emirates. [ABSTRACT FROM AUTHOR]

This paper designs and implements an electro- mechanical propulsion system for a 42-V battery-sourced integrated starter-alternator (ISA) using an indirect-field-oriented (IFO) controller with a speed sensor on the shaft of the machine. The design aspects of the ISA energy conversion system are discussed, with emphasis on the motor selection and comparison of various candidate machines, power electronics, motor controller development and its integration with the engine controller, and a strategy for charging and discharging the energy source. A boost converter powered by the 42-V battery charges three 1-F ultracapacitors to 300 V, thus running the motor drive system at 300 V. The designed 300-V motor drive system is compared with the 42-V drive system directly powered by the 42-V battery. To improve the performance of the propulsion system, two modifications are proposed in this paper. First, terminal-quantities-based accurate voltage and current model flux observers (CMFOs) are designed, which can be used for any off-the-shelf machine. Second, a current model flux-observer-based sensorless controller is presented, which eliminates the need for the speed sensor on the rotor shaft, thus reducing the cost as well as the maintenance of the drive system. The proposed terminal-quantities-based flux observers and sensorless controller form the core of direct and IFO controllers commonly used in any alternative energy vehicular application including the ISA. The designed voltage model flux observer is insensitive to the stator resistance, and the CMFO is insensitive to the rotor resistance and speed, thus overcoming the long-standing problems in the area of flux observer design. The experimental results obtained while driving the vehicle are presented to demonstrate the effectiveness of the prototype ISA and to investigate its performance requirements as a sensorless drive system. Finally, the performance of the proposed flux observers and sensorless controller is evaluated through experimental results on a prototype induction machine to evaluate their potential for implementing a sensorless ISA drive system. [ABSTRACT FROM AUTHOR]

Development of design skills in engineering students at United Arab Emirates University is achieved using an integrated learning approach which consists of structured, guided, and open-ended design experiences. This paper presents a description of the structured design experience in terms of main objectives, implementation mechanisms, and assessed outcomes as applied to freshman laboratory courses in the College of Engineering. These courses are developed to introduce structured design experience through step-by-step, hands-on procedures which guide students to complete particular learning assignments. The coursework spans a wide range of typical engineering practice, such as measurement, calibration, error and tolerance determination, data acquisition, and control. Finally, the course assessment mechanism is presented as a means of ensuring the successful achievement of Accreditation Board for Engineering and Technology educational outcomes. [ABSTRACT FROM AUTHOR]

This paper focuses on a method for achieving robust direct field orientation control of an induction machine using a closed-loop voltage model flux observer that is insensitive to stator resistance variation and does not require voltage signal information, thereby eliminating the need for a voltage sensor. In contrast, the conventional voltage model observer topology requires voltage sensors and is highly sensitive to stator resistance variation, especially at low speed. The closed-loop sliding-mode voltage model flux observer presented here is based on current estimation error including a sliding-mode function which is a derivative of the stator flux. The newly designed sliding-mode function will not only drive the estimated current to the measured one, it will also directly give the estimation results for the terms (stator flux) replaced by the sliding-mode function. The constructed observer and chosen sliding-mode function also do not require information about parameters contained in the terms replaced by the sliding-mode function, i.e., voltage signal and stator resistance. The observer stability is verified in the paper. Simulation and experimental results are also used to illustrate features of the proposed observer. [ABSTRACT FROM AUTHOR]

Presents a study which utilized a close loop current model flux observer to estimate the rotor flux, position and velocity of an induction machine. Methodology for the proposed flux and speed observers; Computer simulation results; Performance of the proposed algorithm on speed command signals.