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This paper presents recent repetitive control (RP) techniques applied to uninterruptible power supplies (UPS). A proportional-derivative (PD) technique including a feedforward term is implemented as the main controller. In addition, recent repetitive control laws are presented and applied to a single phase PWM inverter. It is also presented a new RP approach for repetitive gain adaptation in the presence...
The control of the current distribution in a two leg interleaved inverter is analyzed in this paper. Feedback is used in order to control the current distribution on the inverter legs, avoiding the use of bulky and costly passive solutions. Low THD in the output voltage is ensured by a PI compensator and a repetitive controller. The design of the current compensators was accomplished by approximating...
This work deals with the viability analysis and photometric comparison between two different systems concepts for public lighting, hence the solid state lighting (SSL) employing high power LED luminaries with integrated electronic converters and the conventional high pressure sodium (HPS) lamp based luminaries along with electromagnetic ballasts. The study and comparison stem on the relative perception...
This paper describes the procedures and results of a study to evaluate the quality and determination of the electromagnetic losses in ballasts used for the illumination of large areas (as the ones in industry buildings) or in public lighting networks. A number of new and old high pressure sodium and mercury vapor lamp ballasts were tested, which are adopted by the energy company ENERGISA S. A., with...
In this paper is proposed an algorithm for the selection and specification of three-phase induction motors (MIT), using the equivalent circuit parameters. The equivalent circuit parameters are calculated with manufacter's data. With the circuit parameters is possible to select a MIT that better takes account of load characteristics. The algorithm result's are compared with traditional methods. Experimental...
This paper proposes a model based predictive controller for direct power control of DFIG. The control law is derived by optimization of an objective function that considers the control effort and the difference between the predicted outputs (active and reactive power) and the specific references, with predicted outputs calculated using a linearized state-space model. Because the generator leakage...
Current developments in globalized markets lead to an increasing need for flexible and reconfigurable production systems. By means of automatic reconfiguration of real-time capable communication networks, the effort to perform changes in production systems can be tremendously reduced. This paper proposes new approaches for automatic reconfiguration for robot cells and their equipment on the one hand,...
Networked Control Systems (NCS) have become a widely considered research topic. This new control approach differs from the traditional fieldbus systems in that the controller and the plant are physically separated and connected through an industrial network. The major challenge of NCS design is the limited data feedback using the communication network (network delays and packet loss), which can degrade...
This paper discusses the development and implementation of a system of remote sensing applied to surfboards to be used, especially, in athlete coaching. The developed system uses ZigBee technology to transmit data and uses the experimental analysis of mechanical stress of the materials for the acquisition of the variables to be analyzed. It is basically composed by two modules, called Remote Central...
In this paper, we propose a new method to locate faults on overhead power transmission lines. Line-to-ground or line-to-line faults induce transient currents in the shield wire, which flow partially to ground through the towers. In the towers closest to the fault position, the transient currents are greater and this behavior can be used to locate the fault. The method uses sensors distributed along...
This paper proposes a new method for detection and location of lightning strokes to overhead power transmission lines. The method uses sensors distributed along the transmission line, placed on the top of the towers, to detect and locate the stroke by measuring the stroke currents flowing from shield wires to the towers. When a lightning strikes the shield wire, the stroke currents flow from the wire...
This paper presents an on-line fault diagnosis software in primary distribution feeders. The software is written in DELPHI and C++ languages and its interaction with the operator is made in a very friendly environment. The input data are the currents of the feeder per phase, monitored only in the substation. An artificial immune system was developed using the negative selection algorithm to detect...
Dynamic voltage compensators have been playing important role in the protection of sensitive loads against disturbances, as voltage sags and swells. One implementation option for such equipment is based on the use of a conventional three-phase inverter, which is not able to inject zero sequence components. This paper evaluates the performance of a dynamic sag compensator without zero sequence injection...
This study aims to establish an alternative methodology for determination of the main transients on brushless exciters due to transients in the main generator armature. The method consists in calculating, from design data, the parameters of the equivalent circuits of the main generator and the exciter, followed by simulations, with the software PSIM®, of the worst voltage and current transients in...
In the present work the model of an electromagnetic device that corresponds to an electric machine with stator core fault is presented. The acquisition process of the mathematical model and the equivalent Bond Graph model is based on its Magnetic Equivalent Circuit derived from the idealized physical system. From the experimental results, the non-linear characteristic of the magnetic material is reproduced...
The electromagnetic structure of the proposed induction planar actuator (IPA) comprehends a static ferromagnetic core with an aluminium slab as secondary, and a primary moving part called mover. The latter is fitted with three-phase orthogonal windings assembled on a slotted core that produces a linearly moving magnetic field. The interaction between the magnetic field and the electrical currents...
This paper describes the development and a real application of a new digital self-tuning control scheme when applied to a damped pendulum system for trajectory tracking. The proposed control technique is derived from the optimization of a quadratic performance index which includes an additional weighted derivative term. The self-tuning control action is implemented with a recursive identification...
This paper intends to present a mathematic model of operation of a headbox designed for papermaking, analyzing possible setups of the productive process through stock jet speed, as well as the variables of lip opening and jet-to-wire ratio. On the progress of this work are simulated the control regulators of pressure and jet speed, permitting its optimization in amplitude, and performance evaluation...
In the process industry the loop problem is how to choose a suitable set of PID parameters because of their influence on the asymptotic stability of the system. This paper develops a PID control algorithm based on Internal Model Control (IMC) design for linear and nonlinear control systems in the discrete-time domain under satisfactory performance. Compared with traditional feedback controllers, IMC...
This paper proposes a robust multivariable predictive control algorithm that improves the robustness of closed loop systems, even when they have multiple time delays between the inputs and outputs. The desired robustness is achieved by including an appropriate filter on the disturbances model. The proposed algorithm is applied to the control of humidity and temperature of a neonatal incubator. Simulation...
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