Evaluating the reliability of NAND multiplexing with PRISM

Probabilistic-model checking is a formal verification technique for analyzing the reliability and performance of systems exhibiting stochastic behavior. In this paper, we demonstrate the applicability of this approach and, in particular, the probabilistic-model-checking tool PRISM to the evaluation of reliability and redundancy of defect-tolerant systems in the field of computer-aided design. We illustrate the technique with an example due to von Neumann, namely NAND multiplexing. We show how, having constructed a model of a defect-tolerant system incorporating probabilistic assumptions about its defects, it is straightforward to compute a range of reliability measures and investigate how they are affected by slight variations in the behavior of the system. This allows a designer to evaluate, for example, the tradeoff between redundancy and reliability in the design. We also highlight errors in analytically computed reliability bounds, recently published for the same case study

Rol de la electrónica de potencia en las energías renovables y la calidad de red

1. Estudio teórico del control no lineal en accionamientos eléctricos enfocados a la generación de energía eléctrica basados en fuentes de energías renovables. 2. Metodologías de control no lineal aplicados a convertidores de potenciaCONACYT - Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Finite-fixed switching predictive control technique for a 7-level cascaded H-bridge multilevel active power filter. A comparative study.

This paper presents a finite-fixed predictive control technique applied to the three-wire cascade H-bridge multilevel converters for active power filter applications. The focus of this paper is to examine the impacts of the use of optimum modulation techniques combined with predictive current control in order to increase the control performance in terms of reactive power compensation and total harmonic distortion.CONACYT – Consejo Nacional de Ciencia y Tecnologí

Research in power electronics and control

Fault-tolerance is one of the most interesting feature of wind energy conversion systems (WECS). The ability to maintain operation even after an open-phase fault, allows for the system operators to maintain energy production, providing tangible economic benefits.CONACYT – Consejo Nacional de Ciencia y Tecnologí

Predictive-fixed switching frequency technique for six-phase wind energy conversion systems

This paper presents a speed control with an enhanced predictive current control technique with fixed switching frequency applied to the six-phase wind energy conversion systems. Simulation results show the efficiency of the proposed technique, demonstrating that it is a viable alternative to conventional predictive controllers.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

A review of existing evaluation methods for point clouds quality

This paper analyzes the existing evaluation methods for the point cloud quality and a new discussion regarding their applicability to aerial photographs is opened. Some of these methods are chosen based on practical issues and applied to a pair of reconstructions. The principal conclusion is that objective methods are the most interesting in photogrammetry applications, particularly the comparison between two point clouds.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Modulated model based predictive control with switcher of redundant states for a three-phase cascade H-bridge multilevel STATCOM

Due to problems caused by variable switching frequency a modulated model based predictive control was proposed for different topologies and their applications. However, for cascade H-bridge multilevel converters, there is another problem, the imbalance in the dc-link voltages. This paper proposes extend the modulated model based predictive control to a cascade H-bridge 7-level STATCOM, further including a switcher of redundant states to solve the imbalance voltage issue. Simulation results show improvements in terms of mean squared error, total harmonic distortion and balance voltages in the dc-links.CONACYT – Consejo Nacional de Ciencia y Tecnologí

Attitude tracking of a tri-rotor uav based on robust sliding mode with time delay estimation

The paper presents a robust sliding mode with time delay estimation method for controlling the attitude of a tri-rotor unmanned aerial vehicle (UAV) in presence of uncertainties and disturbances. The proposed control algorithm allows high accuracy tracking since a good disturbance estimation is provided using time delay estimation method and allows chattering reduction. The stability analysis of the closedloop system is presented using the theory of Lyapunov. Finally, two numerical simulations are presented in the presence of disturbances to show the effectiveness of the proposed nonlinear control scheme.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Nonlinear backstepping with time delay estimation for six-phase induction machine

In this paper, a robust nonlinear stator currents controller based on a known nonlinear technique is proposed for a six-phase induction machine. First of all, a proportional-integral regulator is used in an outer loop to control the speed. Secondly, the inner loop based on a nonlinear method that combines the nonlinear backstepping control scheme with the time delay estimation consists of controlling the stator currents. The chosen time delay estimation method can approximate the unmeasurable rotor current while the nonlinear backstepping can achieve good tracking performances. The stability analysis of the current closed-loop error dynamics is provided based on a recursive Lyapunov function. Numerical simulations have been conducted to demonstrate the efficiency and the performance of the developed nonlinear control method for the asymmetrical six-phase induction machine.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI