Preliminary Overview of the Economies of Latin America and the Caribbean 1999

Includes bibliography

Preliminary Overview of the Economies of Latin America and the Caribbean 2006

Includes bibliography

Variable speed refrigeration system with HPF input rectifier stage

This paper is based on the analysis and implementation of a new drive system applied to refrigeration systems, complying with the restrictions imposed by the IEC standards (Harmonic/Flicker/EMI-Electromagnetic Interference restrictions), in order to obtain high efficiency, high power factor, reduced harmonic distortion in the input current and reduced electromagnetic interference, with excellent performance in temperature control of a refrigeration prototype system (automatic control, precision and high dynamic response). The proposal is replace the single-phase motor by a three-phase motor, in the conventional refrigeration system. In this way, a proper control technique can be applied, using a closed-loop (feedback control), that will allow an accurate adjustment of the desirable temperature. The proposed refrigeration prototype uses a 0.5Hp three-phase motor and an open (Belt-Drive) Bitzer IY type compressor. The input rectifier stage's features include the reduction in the input current ripple, the reduction in the output voltage ripple, the use of low stress devices, low volume for the EMI input filter, high input power factor (PF), and low total harmonic distortion (THD) in the input current, in compliance with the IEC61000-3-2 standards. The digital controller for the output three-phase inverter stage has been developed using a conventional voltage-frequency control (scalar V/f control), and a simplified stator oriented Vector control, in order to verify the feasibility and performance of the proposed digital controls for continuous temperature control applied at the refrigerator prototype. ©2008 IEEE.

Power losses analysis and cooling system design of three topologies of multilevel inverters

This paper presents the comparison of three topologies of multilevel inverters applied to drive an induction motor of 500 kVA/4.16 kV. The multilevel inverters analyzed are: a neutral point clamped inverter, a symmetrical cascaded multilevel inverter and a hybrid asymmetrical cascaded multilevel inverter. The performance indexes used in the comparison are total harmonic distortion, first order distortion factor, semiconductors power losses distribution and heat-sink volume. The comparison is developed with the purpose of finding the efficiency and the heat-sink volume where the three systems present the same output filter. ©2008 IEEE.

The outlook for agriculture and rural development in the Americas: a perspective on Latin America and the Caribbean, 2010

Includes Bibliography

Latin America and the Caribbean: policies to improve linkages with the global economy

Includes bibliography

América Latina y el Caribe: la propiedad intelectual después de los tratados de libre comercio

Incluye Bibliografía

Review of Caribbean economic and social performance in the 1980's and 1990's

Includes bibliography

Structural change and productivity growth, 20 years later: old problems, new opportunities

Includes bibliography

Opportunities for convergence and regional cooperation: Unity Summit of Latin America and the Caribbean

Includes Bibliography

Building SME competitiveness in the European Union and Latin America and the Caribbean: policy proposals by the private sector

Includes bibliography

Trolleybus power system for operation with AC or DC distribution networks

This paper presents the development and experimental analysis of a special input stage converter for a Trolleybus type vehicle allowing its operation in AC (two wires, single-phase) or DC distribution networks. The architecture of proposed input stage converter is composed by five interleaved boost rectifiers operating in discontinuous conduction mode. Furthermore, due to the power lines characteristics, the proposed input power structure can act as AC to DC or as DC to DC converter providing a proper DC output voltage range required to the DC bus. When operation is AC to DC, the converter is capable to provide high power factor with reduced harmonic distortion for the input current, complying with the restrictions imposed by IEC 61000-3-4 standard. Finally, the main experimental results are presented in order to verify the feasibility of the proposed converter, demonstrating the benefits and the possibility for AC feeding system for trolleybus type vehicle. © 2010 IEEE.

A HPF AC-AC converter for Permanent Magnet Generator applications

This paper describes the design and development of a high input power-factor (HPF) AC to AC converter for naval applications using Permanent Magnet Generator (PMG). The proposed converter comprises an isolated three-phase uncontrolled multipulse rectification stage directly connected to a single-phase inverter stage, without the use of DC to DC intermediary stage, resulting in more simplicity for the overall circuitry, assuring robustness, reliability and reduced costs. Furthermore, the multipulse rectifier stage is capable to provide high power factor and input currents with low total harmonic distortion (THD). The output voltage of the PMG varies from 260V rms (220 Hz) to 380V rms (360 Hz), depending on load conditions. The output single-phase inverter stage was designed to operate with wide range of DC bus voltage, maintaining 120V rms, 60 Hz output. Measured total harmonic distortion for the AC output voltage represents less than 2%, at 3.6kW nominal linear load. © 2010 IEEE.

Policy alternatives and strategies for the Plurinational State of Bolivia following the end of trade preferences

Include bibliography

Caribbean trade and integration: trends and future prospects

Includes Bibliography