Liliana Cortez

A direct torque control for a PMSM

For a long time, permanent magnet synchronous motors (PMSM) were only applied in some particular fields, e.g. for servo drives. However, in recent years PMSM gained increasing importance in novel domains like automotive hybrid drive trains. For Mexico, this boom represents a valuable opportunity for universities and research institutions, so that together with Mexican industry of the Electric Vehicle (EV) forming partnerships that result in an infrastructure that will enable the country to develop its own technology in terms of EV. This paper presents a competent and not complex direct torque controller (DTC) for PMSM drives.

Implementation of the direct torque control (DTC) in current model, with current starting limiter

This paper presents the scheme of Direct Torque Control (DTC) for induction motor drives, where flux and torque of the motor are estimated by the IM current model. Its scheme requires the knowledge of speed, rotor time constant and inductive parameters of the motor. The results prove the excellent characteristics for torque response and efficiency, which confirm the validity of this control scheme. Due to the rapid response offered by the DTC, this causes a high star current inversor protections activating. To resolve this, is presents the implementation of a closed loop of current vector the optimum switching table that limits the current and put into operation to the DTC. Experimental tests demonstrate effectiveness.

Development and Application of Interactive Virtual Tour to Berdyansk State Pedagogical University

Introduction of modern computer technologies, namely the development of interactive virtual objects in the learning process can achieve significant results in terms of dynamic update of the educational process organization, its forms and methods; it will also give students an opportunity to actively participate in the preparation and implementation of these changes.Development of an interactive model of architectural tour to Berdyansk State Pedagogical University with the help of three-dimensional graphics is actual because, firstly, in the present time there is no visualization of this architectural complex from the aesthetic and historical perspective. The University building has an interesting history, and we as the heirs need to preserve the memory of it. Secondly, there’s a cognitive and informative component: you can always help an applicant, a student, a lecturer or a visitor to plunge into the atmosphere of the educational establishment, see the plan of the lecture rooms, and show to a general viewer the architectural elements and to interact with many elements of the interior space. Thirdly, this project can be used in advertising and career-oriented work. And it is an affordable and easy resource due to intensive development of computer technologies, one of the important directions of which is Internet-based technologies.

Study of a hybrid storage system for a Photovoltaic Energy System

In this work a hybrid storage system, composed by a battery and supercapacitors, is evaluated in order to improve the voltage output signal of a Photovoltaic Energy System. First, it is presented a strategy to load the storage system, followed by a discussion of the strategy to take the energy from the storage system. Finally, the results of applying the former strategy to improve the output signal of an AC/AC converter are showed.

Performance evaluation of an OFDMA and CDMA overlaid system

The overlay systems appear due to the evolution of the mobile telephony, in fact currently exist 3G and 4G simultaneously, for this reason the impact and feasibility of an OFDMA cellular system overlaid is studied. 3G systems based on CDMA offer important characteristics and services to the users, besides a good capacity and service quality. 4G systems are the most recent technology and are based on OFDMA that is considered as the evolution of CDMA. OFDMA has demonstrated to have good efficiency, robustness to several channel effects and response to interference. In fact we are living the migration from 3G to 4G systems. In this work we evaluate the impact of this overlay situation.