Antonio Heronaldo de Sousa

The objective of this work is to show the operation of a system that allows monitoring, controlling and configuring a wireless household-electric network. The user interface of this system is done through a personal digital assistant (PDA). Initially, the wireless communication was established by the Bluetooth protocol. It was used a hardware module which provided the communication between the PDA and the microcontroller embedded in the household-electric. In the next step, it will be implemented modifications in the hardware and firmware of the appliance, to implement functions using a microcontroller with integrated ZigBee protocol. In the implementation of the user interface, it is being used the JAVA programming language, which allows the portability of the interface to the Palm, windows and symbian operational systems used in PDAs and smartphones.

This paper investigates two control strategies for application in single-phase induction motor drives. The objective is to implement a low-cost solution for low-power applications. The first method to be used is the direct torque and flux control (DTC). A switching table was derived based on the voltage vectors generated by the three-leg two-phase inverter topology. The second method uses SVPWM-DTC technique. The basic operating principle of SVPWM is described. Simulations were carried out and performance analysis is presented.

In this work are developed two on-line identification methods for induction motors based on discrete models obtained when we consider continuous systems excited by sinusoidal signals. The first method uses the discrete model of the homopolar machine in the stationary frame to estimate the stator resistance and the stator leakage inductance and the discrete model of the linear system existent among the stator flux and stator current in the rotor frame to estimate all the electric parameters of the motor. The second method, besides this last model, presupposes to estimate the stator resistance with DC excitation added to the supply voltage of the motor and the knowledge of the motor class, in order to estimate the other electric parameters through classical methods of least squares parameters estimation. Simulation and experimental results illustrate the proposed methods

This paper presents a synthesis of the development of two PDA softwares that can be used to monitor and parametrize industrial equipments over Modbus protocol. Moreover, to add a new functionality to the softwares, it was carried out a study about supervisory system and softwares. The result was the design and implementation of a supervisory module to those softwares that allows the entrance of supervisory sentences to control the equipments