A.A. Aboulnaga

A novel, low-cost, high-performance single-phase adjustable-speed motor drive using PM brush-less DC machine: IIT's design for 2003 future energy challenge

This paper presents a novel, low-cost, high-performance single-phase adjustable-speed motor drive by using a three-phase permanent magnet brush-less DC (BLDC) machine. This system has been designed and implemented by the multidisciplinary student team of Illinois Institute of Technology (IIT) for the 2003 IEEE/DOE/DOD international future energy challenge and won the first prize overall award for the motor competition. Machine configurations and driver topologies have been investigated to develop a low-cost innovative system. To satisfy the requirements of the challenge, a commercially available motor has been selected and redesigned including the stator winding and permanent magnet rotor. The redesigned motor has been fabricated and tested successfully. For the designed power electronic driver, the main goal was to achieve high performance and reliability at low cost. Simulation and experimental results are provided to verify the proposed approach.

High performance bidirectional Cuk converter for telecommunication systems

Telecommunication systems mainly need highly reliable power supplies with high efficiency. Other important issues are related to the noise and electromagnetic interference (EMI), which are produced by the power supply. Low EMI means low shielding cost and low distortion of the main communication signal. To meet such essential requirements, a high performance bidirectional Cuk converter-based power supply is proposed in this paper. The converter provides high efficiency, low noise, and low EMI. In addition, the converter has high power density, low cost, and electric isolation. These advantages are achieved from integrating the magnetic components of the converter, the input inductors, the output inductor, and the isolation transformer, on one magnetic assembly. In this paper, the conventional 42 VDC power supply architecture for telecommunication systems is briefly described. A modified system that utilizes the integrated magnetics bidirectional Cuk converter is explained. Finally, the full design integrated Cuk converter, simulation results, and practical performance evaluation are presented.

Performance evaluation of the isolated bidirectional Cuk converter with integrated magnetics

In this paper, an isolated bidirectional DC/DC Cuk converter featuring high power density, zero input/output current ripples, and symmetrical design is presented. The magnetic components of the converter, which include the input inductor, the output inductor, and the isolation transformer, are assembled together in one magnetic structure. The magnetic assembly is modeled and designed using the gyrator-capacitor (G-C) approach. Simulation and experimental results are presented to verify the converter performance in both forward and backward modes of operation. The effect of the switching frequency on the percentage current ripples is discussed.

Simplified simulation and modeling technique for integrated magnetic components in power electronic converters

The inductance modeling technique is used as the traditional method for analyzing magnetic components. This model is simple to generate for individual components, i.e., an inductor and a transformer. However, it becomes difficult to realize this model for the integrated magnetic structures where multiple inductors and transformers exist on one assembly. In addition, it is difficult to model the effect of the magnetic saturation in the inductance model. This work presents a simple model for the discreet as well as integrated magnetic components. In this model, the magnetic circuit is converted to a pure electric circuit with capacitors; every winding is replaced with a pair of current controlled voltage sources, namely a Gyrator. Finally, the complete simulation model for the isolated Cuk converter with integrated magnetics is presented as an illustrative example.

Future energy challenge: a novel low-cost adjustable speed motor with wide speed range

In this paper, a low cost and high efficiency, 500 W permanent magnet brushless DC (PM-BLDC) motor drive that has been designed and implemented for the 2003 International Future Energy Challenge is presented. This drive is mainly designed to operate over a wide range of speed (from 150 rpm to 5000 rpm) and to operate efficiently at different operating points.

GTO by-pass thyristor based method for improving performance of single-phase AC/DC bridge converters

High power phase-controlled converters suffer from several fundamental disadvantages. They inject current harmonics into the input AC mains due to their nonlinear characteristics, thereby distort the supply voltage waveform and demand reactive power from the associated AC power system at retarded firing angle. In this paper, a novel GTO by-pass thyristor technique is suggested, which, when applied to the conventional AC-DC bridge converter, substantially overcomes these disadvantages. Experimental and theoretical results are given which show a good input power factor, a good waveform of the line current, and a wide adjustable range of the DC output voltage.

Analysis and design of forced commutation circuit for by-pass thyristor-based AC-DC converters

In by-pass thyristor based AC-DC bridge converters, the by-pass thyristor can be either a conventional thyristor or a GTO thyristor. Generally, when the turn off facility is added to the by-pass thyristors, the total harmonic distortion (THD) of the supply current is reduced and the input power factor is successfully improved. This paper presents an alternative modified scheme, where forced commutation is applied to the conventional by-pass thyristors instead of using GTO thyristors. The complete analysis and design of a forced commutation circuit is presented for the single-phase bridge converter with conventional by-pass thyristors. Analytical and experimental results illustrating the benefits obtained from applying forced commutation are presented and discussed.