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ABSTRACT This paper presents an educational tool based on a novel approach to develop an FPGA-based real-time emulator of an induction motor using the dynamic model. The method exploits the parallelism and high speed characteristics of... more
ABSTRACT This paper presents an educational tool based on a novel approach to develop an FPGA-based real-time emulator of an induction motor using the dynamic model. The method exploits the parallelism and high speed characteristics of the FPGA. Different fixed-point representation of the external and internal signal is used. The emulator architecture is presented as well as peripheral units implemented along with the main unit. The real-time emulator is evaluated by experimentation under start-up and varaible load torque conditions. This emulator is the based to implement algorithms like speed and flux estimators, i. e. Extended Kalman Filter, Luenberguer-like observer, etc., and several control schemes like Direct Torque Control, Field-Oriented Control, etc. for induction motors.
In this work, a new time-frequency tool based on minimum-norm spectral estimation is introduced for multiple fault detection in induction motors. Several diagnostic techniques are available to identify certain faults in induction... more
In this work, a new time-frequency tool based on minimum-norm spectral estimation is introduced for multiple fault detection in induction motors. Several diagnostic techniques are available to identify certain faults in induction machines; however, they generally give acceptable results only for machines operating under stationary conditions. Induction motors rarely operate under stationary conditions as they are constantly affected by load oscillations, speed waves, unbalanced voltages, and other external conditions. To overcome this issue, different time-frequency analysis techniques have been proposed for fault detection in induction motors under non-stationary regimes. However, most of them have low-resolution, low-accuracy or both. The proposed method employs the minimum-norm spectral estimation to provide high frequency resolution and accuracy in the time-frequency domain. This technique exploits the advantages of non-stationary conditions, where mechanical and electrical stre...
The electric spring (ES) is a contemporary device that has emerged as a viable alternative for solving problems associated with voltage and power stability in distributed generation-based smart grids (SG). In order to study the... more
The electric spring (ES) is a contemporary device that has emerged as a viable alternative for solving problems associated with voltage and power stability in distributed generation-based smart grids (SG). In order to study the integration of ESs into the electrical network, the steady-state simulation models have been developed as an essential tool. Typically, these models require an equivalent electrical circuit of the in-test networks, which implies adding restrictions for its implementation in simulation software. These restrictions generate simplified models, limiting their application to specific scenarios, which, in some cases, do not fully apply to the needs of modern power systems. Therefore, a robust steady-state model for the ES is proposed in this work to adequately represent the power exchange of multiples ESs in radial micro-grids (µGs) and renewable energy sources regardless of their physical location and without the need of additional restrictions. For solving and co...
El tópico de este artículo, abordará la investigación de una técnica novedosa para la compensación electrónica de la dispersión en comunicaciones por fibra óptica a larga distancia, en la cual una señal es pre-compensada eléctricamente... more
El tópico de este artículo, abordará la investigación de una técnica novedosa para la compensación electrónica de la dispersión en comunicaciones por fibra óptica a larga distancia, en la cual una señal es pre-compensada eléctricamente usando un modulador diferencial Mach-Zender, controlado por filtros digitales no lineales. La dispersión cromática fue efectivamente compensada con el uso del conjugado de fase óptica en el transmisor a través de los 4000 Km de fibra mono modo (carente de no-linealidad y atenuación) en donde la dispersión es compensada para una señal de NRZ (no retorno a cero) de intensidad modulada a 10 Gb/s. La compensación de la dispersión fue confirmada midiendo la razón de error de bit y observando los diagramas de ojo detectados.
The topic of this report will deal with the study of advanced modulation formats for highspeed optical communication systems. Basically, the use of alternate polarization modulation (alP) is considered in order to reduce the inter-symbol... more
The topic of this report will deal with the study of advanced modulation formats for highspeed optical communication systems. Basically, the use of alternate polarization modulation (alP) is considered in order to reduce the inter-symbol interference (ISI) caused mainly by effects such as Chromatic Dispersion (CD), Polarization Mode Dispersion (PMD) and Nonlinear effects. The comparative analysis among the different formats is carried out by means of the obtaining of its different spectrums. A detailed analysis of these and their dependency to the modulation format that generates it is presented. The article presents numerical comparative analysis using commercial software VPI Maker Transmission, where the results obtained show that the formats of alternating polarization are the best results at the bit rate of 40 Gb/s per channel.
For industry, the induction motors are essential elements in production chains. Despite the robustness of induction motors, they are susceptible to failures. The broken rotor bar (BRB) fault in induction motors has received special... more
For industry, the induction motors are essential elements in production chains. Despite the robustness of induction motors, they are susceptible to failures. The broken rotor bar (BRB) fault in induction motors has received special attention since one of its characteristics is that the motor can continue operating with apparent normality; however, at certain point the fault may cause severe damage to the motor. In this work, a methodology to detect BRBs using vibration signals is proposed. The methodology uses the Shannon entropy to quantify the amount of information provided by the vibration signals, which changes due to the presence of new frequency components associated with the fault. For automatic diagnosis, theK-means cluster algorithm and a decision-making unit that looks for the nearest cluster through the Euclidian distance are applied. Unlike other reported works, the proposal can diagnose the BRB condition during startup transient and steady state regimes of operation. Ad...
Nowadays, many industrial applications require online systems that combine several processing techniques in order to offer solutions to complex problems as the case of detection and classification of multiple faults in induction motors.... more
Nowadays, many industrial applications require online systems that combine several processing techniques in order to offer solutions to complex problems as the case of detection and classification of multiple faults in induction motors. In this work, a novel digital structure to implement the empirical mode decomposition (EMD) for processing nonstationary and nonlinear signals using the full spline-cubic function is presented; besides, it is combined with an adaptive linear network (ADALINE)-based frequency estimator and a feed forward neural network (FFNN)-based classifier to provide an intelligent methodology for the automatic diagnosis during the startup transient of motor faults such as: one and two broken rotor bars, bearing defects, and unbalance. Moreover, the overall methodology implementation into a field-programmable gate array (FPGA) allows an online and real-time operation, thanks to its parallelism and high-performance capabilities as a system-on-a-chip (SoC) solution. ...
This paper presents a new EEMD-MUSIC- (ensemble empirical mode decomposition-multiple signal classification-) based methodology to identify modal frequencies in structures ranging from free and ambient vibration signals produced by... more
This paper presents a new EEMD-MUSIC- (ensemble empirical mode decomposition-multiple signal classification-) based methodology to identify modal frequencies in structures ranging from free and ambient vibration signals produced by artificial and natural excitations and also considering several factors as nonstationary effects, close modal frequencies, and noisy environments, which are common situations where several techniques reported in literature fail. The EEMD and MUSIC methods are used to decompose the vibration signal into a set of IMFs (intrinsic mode functions) and to identify the natural frequencies of a structure, respectively. The effectiveness of the proposed methodology has been validated and tested with synthetic signals and under real operating conditions. The experiments are focused on extracting the natural frequencies of a truss-type scaled structure and of a bridge used for both highway traffic and pedestrians. Results show the proposed methodology as a suitable ...

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