Júlio S. Martins

Fuzzy logic speed control of an induction motor

Abstract This paper describes the use of fuzzy logic techniques to control the speed of a three-phase induction motor. The use of Matlab/Simulink and fuzzyTECH MCU96 as software development tools for system design is emphasised. Hardware implementation is based on a standard 16/32-bit microcontroller, without the need of any additional components for the fuzzy logic controller. The system performance is evaluated in comparison with a traditional PI control scheme. Both simulation and experimental results are presented.

A Case Study on the Conversion of an Internal Combustion Engine Vehicle into an Electric Vehicle

This paper presents the conversion process of a traditional Internal Combustion Engine vehicle into an Electric Vehicle. The main constitutive elements of the Electric Vehicle are presented. The developed powertrain uses a three-phase inverter with Field Oriented Control and space vector modulation. The developed on-board batteries charging system can operate in Grid to Vehicle and Vehicle to Grid modes. The implemented prototypes were tested, and experimental results are presented. The assembly of these prototypes in the vehicle was made in accordance with the Portuguese legislation about vehicles conversion, and the main adopted solutions are presented.

A personal computer based controller for an active power filter

This paper presents the development of controllers used in active power filters, applied to improve power quality in electrical systems. These active filters can be able to compensate for the following current or voltage related problems: short blackouts, current or voltage distortion due to harmonics, current or voltage unbalance in three-phase systems, flicker and momentary over or under voltage. There are several causes for current and voltage distortion, namely, non-linear loads, some type of voltage sources and thunderstorms. These problems cause instant and long term effects on the electrical equipment. The short term effects are imperfections, malfunctioning, interferences and degradation of the performance of devices or equipments. Effects in the long run are, basically, overheating and premature aging of the electric devices. The main goal of the work described in this paper is to develop an active power filter controller based on a personal computer and a standard multifunction data acquisition PCI bus card, due to its relative low cost, high processing capability, versatility and the numerous possibilities offered by such a computer-based system. Four different approaches where tested: using C++ on Microsoft Windows with the manufacturers device driver, using a new device driver for Windows, using Linux with real-time application interface; and using LabVIEW for Windows. Experimental and simulation results of the developed controllers are also presented.

A single chip FPGA-based solution for controlling of multi-unit PMSM motor with time-division multiplexing scheme

Display Omitted Propose an area-efficient method based on time-division multiplexing scheme for multi-motor control systems.Present a cost-efficient solution using a single chip FPGA for controlling of multi-unit motor drive systems.Present a complete hardware design methodology using XSG tool for FPGA realization of multi-motor systems. The use of multiple unit controllers for parallel processing of multi-unit motor drive systems can significantly reduce the execution time of the control algorithm. However, this approach does not only increase the system cost but also incurs in additional cost of hardware and software interconnections. This paper presents a fully integrated single chip field programmable gate array (FPGA) based solution for controlling of an independent multi-unit permanent magnet synchronous motor (PMSM) drive system with space vector pulse width modulation (SVPWM) based vector control. For multi-unit motor systems, the complexity of control algorithms often exceeds the resource availability of low-cost FPGA devices. Thus, a system-level time-division multiplexing scheme applicable for multi-motor control systems is proposed. Using the proposed method, large identical complex control algorithms can be simplified into a single compact algorithm, which is fitted and configured into a low-cost FPGA. Simulation modeling and experimental results are shown, confirming the effectiveness of a multi-unit PMSM motor drive system using an inexpensive controller based on system-level time-division multiplexing scheme, which can operate simultaneously with robustness under different operating conditions.

A simplified methodology for parameters measurement of an Axial Flux Permanent Magnet motor without neutral point

Recent developments in the area of electric vehicles resulted in a growing interest for Axial Flux Permanent Magnet (AFPM) Motors, mainly because of their high power density. For the design of the motor drive it is extremely important to have the motor parameters. However many times the manufacturers do not provide them. This paper presents a methodology to overcome this problem, proposes a methodology to obtain the parameters of this AFPM motors, for the implementation of the d-q model of the motor. In permanent magnet synchronous motors the inductance changes with the rotor position, so the d-q model is used to simplify the analysis, modeling and control implementation. This paper presents the d-q model of an AFPM motor with two external stators and one internal rotor.

A microcontroller based voltage space vector modulator suitable for induction motor drives

Pulse width modulation techniques (PWM), introduced two decades ago, are the most used methods to control the voltage and frequency supplied to electrical AC machines. This paper describes a pulse width modulator based on the voltage space vectors technique that accepts voltage demands in dq coordinates and generates three phase PWM waveforms to drive a variable frequency voltage-source inverter. A scheme based on a high performance 16-bit standard microcontroller with minimum of additional hardware is used, which allows a flexible and economical solution. The output frequency of the modulator can be varied in a large range and with a good resolution. Experimental data obtained from an induction motor drive are presented.

Sistema Digital de Bajo Coste para la Monitorización de la Calidad de Energía Eléctrica

This paper describes the development of a low-cost digital system used for power quality monitoring. The system uses voltage and current Hall sensors, a standard data acquisition board, and has its processing system based on LabVIEW™, running on a regular Personal Computer. Several parameters related to power quality can be analyzed through 4 different applications: “Scope and THD”, “Events PQ”, “Classical Values” and “p-q Theory”. The acquired information can be visualized in tables and/or in charts. It is also possible to generate reports in HTML format. In this format, the reports can be sent directly to a printer, can be embedded in other software applications, or can be accessed through Internet, using a web browser.

Multi-mode microcontroller based PWM modulator suitable for fast vector control

This paper describes the development and implementation of a PWM modulator that produces waveforms suitable to control all types of voltage source invertor-fed AC motor drives, from fast vector controllers to high power applications. The modulator provides two basic operation modes: (1) an asynchronous mode, performing an improved version of sinusoidal PWM modulation based on the regular-sampling of a modulating waveform; and (2) a kind of synchronous modulation, where commutation instants are set accordingly to stored pre-calculated optimized PWM patterns. Transition between the two modes can be performed without problems. To implement this PWM control strategy, a 16/32 bit microcontroller is used without any additional components. The system was tested for a small power induction motor and the results are presented.

Digital Control of a Novel Single-Phase Three-Port Bidirectional Converter to Interface Renewables and Electric Vehicles with the Power Grid

This paper presents the digital control of a novel single-phase three–port bidirectional (STB) converter used to interface renewables from solar photovoltaic (PV) panels and electric vehicles (EVs) with the power grid. Using an appropriated power theory, the STB converter can be used to exchange energy between the PVs, the EVs and the power grid in four distinct modes: (1) The EV receives energy from the power grid (G2 V—grid–to–vehicle operation mode) or delivers energy to the power grid (V2G—vehicle–to–grid operation mode); (2) All the energy produced by the PV panels is delivery to the power grid; (3) All the energy produced by the PV panels is delivery to the EV; (4) The EV can receive energy simultaneously from the PV panels and from the power grid (G2 V). The currents of the power grid, PV panels and EV are controlled through independent predictive current control strategies, which ensure good power quality levels. This paper presents the architecture of the proposed STB converter and the detailed explanation of the digital implementation of the control algorithms, namely, the power theory and the predictive current control strategies. The control algorithms were validated through computational simulations and experimental results.

A Single Chip FPGA-Based Cross-Coupling Multi-Motor Drive System

Often, the demand for optimal and harmonious operation of multi-motor control systems requires sharing of feedback information from one drive to other drives. From the point of view of controller implementation, a multi-controller structure degrades the system integration and requires data communication among chips. The aim of this paper is to propose a fully integrated single chip solution for a cross-coupling multi-motor control system. The proposed speed controller with time-division multiplexing scheme can simplify the entire system, making possible the implementation on a single device. The experimental results confirm the implementation feasibility and the effectiveness of the proposed single chip system.