Edgard L. L. Fabricio

Single-Phase to Three-Phase Drive System Using Two Parallel Single-Phase Rectifiers

This paper proposes a single-phase to three-phase drive system composed of two parallel single-phase rectifiers, a three-phase inverter, and an induction motor. The proposed topology permits to reduce the rectifier switch currents, the harmonic distortion at the input converter side, and presents improvements on the fault tolerance characteristics. Even with the increase in the number of switches, the total energy loss of the proposed system may be lower than that of a conventional one. The model of the system is derived, and it is shown that the reduction of circulating current is an important objective in the system design. A suitable control strategy, including the pulsewidth modulation technique (PWM), is developed. Experimental results are presented as well.

Shunt Active Power Filter With Open-End Winding Transformer and Series-Connected Converters

This paper presents a shunt active power filter based on the concept of open-end winding (OEW) transformers. The proposed configuration is constituted of two converters with three legs each series connected throughout a three-phase OEW transformer. Model PWM strategy and control scheme are presented as well. The main advantage of the proposed system lies on the multi-level waveform generation, which allows reduction of either harmonic distortions or switching losses. This proposed topology is suitable for medium voltage (MV) distribution systems. Simulation and experimental results validate the theoretical study.

Shunt compensator based on three-phase interconnected converters

This paper investigates a three-phase shunt power filter based on three standard three-phase interconnected converters. Compared with the usual three-phase shunt filter, the proposed converter permits to reduce the dc-link voltages and reduce either harmonic distortion or switching frequency. Control strategies suitable to control the filter and circulating currents as well as the three dc-link voltages are presented. A PWM strategy is designed to command the converter according to the reference voltage generated by the controllers. Simulation and experimental results are presented.

Y-Connected Three-Leg Converters Applied in Three or Four-Wire Shunt Compensator

This paper investigates power shunt filter topologies composed of three standard three-leg converters applied in either three or four-wire system. Compared with the usual three-phase shunt filter, the proposed ones allow us to reduce dc-link voltages, harmonic distortion or/and the semiconductor losses, and fault tolerant operation. Suitable control strategies to adjust filter and circulating currents, as well as the three dc-link voltages are presented. Two pulse-width modulation techniques are developed for the proposed topologies in order to achieve the best voltage-pulse pattern. Comparisons between these techniques are carried out in this paper. Simulation and experimental results are presented to validate the theoretical approach.

Shunt Compensator Based on Interconnected Three-Phase Converter

This paper presents a shunt power compensator based on the interconnection of three-phase two-level converters, and its comparison with two-level- and multilevel-based topologies. The shunt power compensator based on interconnected three-phase converter (ITC) is compared with compensators based on the two-level converter, three-level neutral-point clamped converter, and five-level modular multilevel converter. The comparisons were done in terms of components ratings, harmonic distortion, and semiconductor losses. Control strategies suitable to control the compensator and circulating currents, as well as the three-dc-link voltages are presented. The PWM strategy to generate the control reference voltages of the converter command is designed. Simulation and experimental results are presented.

Analysis of Main Topologies of Shunt Active Power Filters Applied to Four-Wire Systems

This paper presents a complete comparative study about the five most common configurations of shunt active power filter applied to four-wire distribution systems. In order to evaluate the applicability of the studied topologies, two scenarios of four-wire loads are investigated differing by level of zero-sequence harmonic contents. The analysis of simulation steady-state results comprise dc-link capacitor voltage and current stresses, harmonic distortion in grid currents, and semiconductor losses. The results show that structures with fourth inductor generate higher number of levels at output converter voltage. However, when they operate by compensating high levels of zero-sequence harmonics, they can present higher dc-link voltage and lower efficiency. Furthermore, system models, control strategy, and experimental results are presented as well.

Single-phase to three-phase five-leg converter based on two parallel single-phase rectifiers

This paper proposes a single-phase to three-phase converter. Such configuration is composed of two parallel single-phase rectifiers and a three-phase inverter operating at same frequency of the grid voltage. The proposed topology has advantages over the standard one due to: a) reduced power rating of the rectifier switches, which means switches operating at equivalent power rating; b) reduced costs if the price of switches with different power ratings is higher than the cost of switches with close ratings; and c) fault tolerance in the rectifier circuit. The model of the system is derived and a suitable control strategy, including the PWM technique, is developed. Experimental results are presented, as well.

Multilevel Converter Based on Cascaded Three-Leg Converters with Reduced Voltage and Current

In this paper, a modularity concept using standard three-leg converters is addressed. Three-phase cascaded topologies composed of standard three-leg converters are investigated. They are composed of three, nine, twenty-one, or

Three-phase shunt active power filter based on the interconnection of single-phase and three-phase converters

n

Multilevel converter based on cascaded three-leg converters with reduced voltage and current

three-leg converters. It permits the reduction levels of currents and voltages on switches when compared with a conventional three-phase module or a cascaded H-bridge structure. In this way, three-leg cascaded converters are suitable to be applied in scenarios of high current in which other cascaded topologies become less attractive and high voltage. Furthermore, the proposed arrangement brings advantages such as modularity that leads to convenient construction, easy maintenance, and extension to higher voltage and current levels. A dynamic model is developed and a pulse-width modulation strategy is designed to the converter command accordingly with reference voltage. Discussions about fault tolerance and dc-link capacitor currents are also carried out. Comparisons in terms of converter rating, harmonic distortion, and semiconductor power losses between the proposed and conventional cascaded H-bridge topologies have been carried out. Simulation and experimental results are presented as well.