Edson Adriano Vendrusculo

High-efficiency regenerative electronic load using capacitive idling converter for power sources testing

This paper presents a regenerative electronic load developed for testing in a didactic electrical machines laboratory, and which is also suitable for burn-in test of power supplies. The basic topology is a capacitive idling Cuk converter. This converter allows independent control of the input current and permits provision of a sinusoidal output current, while assuring the power balance. An appropriate gate command allows some soft-commutation without the use of any auxiliary circuit. Design criteria and experimental results of a 1 kW prototype are presented.

Low-loss, high power factor voltage supply using a capacitive idling converter

Capacitive idling power converters derived from the Cuk and SEPIC topologies can operate as power supplies with input power factor correction. These power converters allow soft-commutation of their power switches without the need of additional circuitry, making it possible to increase the switching frequency while maintaining high efficiency. A simple high-frequency transformer allows output isolation. The input current and output voltage can be controlled by commercial ICs. EMI filter requirements are minimized by operating in high switching frequency and continuous current mode. Detailed design guidelines and circuit analysis are presented together with experimental results on a 500 W, 100 kHz prototype.

Analysis of a derivative hybrid power filter in distorted voltage grid

This paper presents the analysis of a derivative hybrid power filter in distorted voltage grid. The feeder has linear and nonlinear loads and two tuned passive filters connected to the same point of common coupling. As the voltage distortions can excite the series resonance of the passive filters. In order to avoid such effects an active filter is connected in combination with one tuned passive filter forming a derivative hybrid power filter. With the proposal control strategy, the derivative hybrid power filter is able to mitigate the high currents due to the series resonance, independently of their origin. Experimental results show the derivative hybrid power filter capability for filtering the current harmonics and mitigating the resonance effects.

Analysis of control strategy and dimensioning of Hybrid Active power filter with reduced inverter power rating

This work analyzes the compensation of harmonic currents through a Hybrid Filter. The Hybrid Filter consists of an active power filter connected in parallel with the inductor of a shunt passive tuned filter, resulting a lower voltage and current stress over the active filter. The paper investigates the behavior of an open loop control strategy, and discusses the dimensioning of the power converter. Simulation results verify the system operation.

Integrated platform for power electronics applications fast evaluation and teaching purposes

The purpose of this paper is to present a custom solution for power electronics systems control and teaching, based on fast simulation and evaluation of classical and/or modern control strategies. The system is composed by the plant to be controlled, a DSP, a PC and interfaces boards. The objective of the platform is to gradually introduce the students from the initial design phase to practical experiences in laboratory with shortened design cycle. In addition, the platform allows them to be prepared to handle advanced programs and to build their own software algorithms and hardware interfaces. An application for a DC motor drive is presented and evaluated. I. INTRODUCTION Applications based on power electronics usually allow a relative low cost and fast implementation, what is useful for evaluating different control strategies in experimental activities.

An adaptive speed estimator for single-phase induction motors

In this paper, a mechanical speed estimator based on the model reference adaptive-system (MRAS) principle is evaluated for a single-phase induction motor operated as two-phase motor. In three-phase drives with complete vector control/MRAS system the effect of the rotor time constant is auto-compensated by the decoupling compensators or slip calculation. However, it is not feasible in pure MRAS scheme application. Further, the asymmetrical main and auxiliary windings of single-phase motors increase the estimator sensitivity to parameter mismatch and environment change. The MRAS is evaluated when the error vector choice relies on observing the counter electromotive force vector, instead of flux based MRAS structures. Also, it is analytically shown that instantaneous reactive power principle does not suppress the stator resistance in MRAS speed estimation of single-phase motor. The MRAS observer was tested under offset, no load operation and field- weakening region conditions. The MRAS performance was successful even to sharply frequency-step transitions.

Soft commutation in capacitive idling converters

The capacitive idling converters derived from the Cuk, SEPIC, Zeta, and flyback topologies allow soft commutation of power switches without the need for additional circuitry, making it possible to increase the switching frequency while maintaining high efficiency.

Power Equalization Techniques for Three-Phase VSI-Driven Single-Phase Ozone Generators

The purpose of this article is to present a method to equalize power imbalances in single-phase loads driven by three-phase voltage source inverters. The objective is to unbalance the line-to-line voltages in order to equalize the individual load power. The method is evaluated under non-linear loads, considering the dispersion of the high-voltage transformer electrical parameters values usually found in ozone generating systems. Two methods are considered for equalizing the load power. In the progressive method, the power equalization is performed by a microcontroller and works setting up the voltage applied over each load in response to power feedback from the other loads. In addition, Fuzzy Logic concepts are also applied, permitting a fast response, in spite of lower precision in the power balancing. Analytical, simulation and experimental results validate both methods.