Ademir Nied

Benchmark for Peak Detection Algorithms in Fiber Bragg Grating Interrogation and a New Neural Network for its Performance Improvement

This paper presents a benchmark for peak detection algorithms employed in fiber Bragg grating spectrometric interrogation systems. The accuracy, precision, and computational performance of currently used algorithms and those of a new proposed artificial neural network algorithm are compared. Centroid and gaussian fitting algorithms are shown to have the highest precision but produce systematic errors that depend on the FBG refractive index modulation profile. The proposed neural network displays relatively good precision with reduced systematic errors and improved computational performance when compared to other networks. Additionally, suitable algorithms may be chosen with the general guidelines presented.

Soft Starting of Induction Motor with Torque Control

This paper presents a simple technique based on stator-flux estimation to control the electromagnetic torque of induction motors (IMs) during soft starting. The inherent problems related to pure integration of the back electromagnetic force to estimate the stator flux are minimized using the low-pass-filter approach. The experimental results are dealt with and compared with the usual current-control technique. The results obtained validate the proposed technique, showing its viability in applications where the objective is to fit the IM torque profile during starting or stopping according to the load torque.

SVPWM-DTC Strategy for Single-Phase Induction Motor Control

A SVPWM-DTC strategy to control a single-phase induction motor drive is investigated in this paper. The basic operating principles of DTC and SVPWM are described. The objective is to implement a low-cost solution for low-power applications. As DTC scheme do not require the use of speed or position signal for torque control, this technique is a good solution for single-phase induction motor. In this paper, a dq model for single-phase motors in the stator reference frame is implemented. Simulations were carried out and performance analysis of the scheme is presented.

Single-Phase Induction Motor Control Based on DTC Strategies

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.

Model-based predictive direct speed control applied to a Permanent Magnet Synchronous Motor with trapezoidal back-EMF

This paper presents an investigative work about the application of State Space Model-Based Predictive Control in a three-phase Permanent Magnet Synchronous Motor with trapezoidal back-electromotive force, for speed control. Such motor is utilized in the white goods appliances industry and also in automotive and medical applications, among others, especially due to its high efficiency and long life cycle. The predictive control methods present a differential in the driving performance for industrial applications, mainly by enabling the imposition of constraints. In this work, a linear prediction model identified with a Least Mean Squares algorithm is used with the State-Space predictive control approach. Such predictive method is interesting for industrial applications for being easy to tune and, in addition to the imposition of constraints, allowing ponderation between tracking performance and spent energy. The utilization of constraints is discussed for the predictive algorithm in this work. There are satisfactory simulated and experimental results that show advantages in using the mentioned control method to drive the Permanent Magnet Synchronous Motor.

Single-phase induction motor indirect field oriented control under nominal load

This paper discusses the performance of a single-phase induction motor drive under nominal load in a closed-loop vector-controlled system. The control strategy to be applied is known as indirect field oriented control. Single-phase induction motor when operating as two-phase motor has its dynamic performance increased. With the use of a standard three-phase voltage-source inverter, space vector pulse width modulation can be implemented. Experimental results show the effectiveness of the control system.

Direct torque control of induction motor soft starting

This paper presents a simple technique based on stator flux estimation to control the electromagnetic torque of induction motors during soft starting. The inherent problems related to pure integration of the back electromagnetic force to estimate the stator flux are minimized using the low pass filter approach. The experimental results are dealt with and compared to the usual current control technique.

Web-based learning of electrical machines simulation tool - iMotor

The web-based learning is rapidly emerging as an alternative to the traditional classroom. Todays students have a visual learning ability and skill with technological resources towering previous generations. Thus, the use of an open source simulation tool for electric machines in web platform made in the Model-View-Controller pattern is an appeal to help teachers and students to learn the dynamic behaviour motors in undergraduate and graduate degree in Electrical Engineering.

Evaluation of constrained and unconstrained SESSMPC applied in five-phase PMSM

This work presents a comparative analysis of a successively evaluated state space model-based predictive control approach used to drive a five-phase permanent magnet synchronous motor. It is presented a five-phase motor modelling and control theoretical basis main concept, including the prediction model preparation, as well unconstrained and constrained formulations. Both formulations are used and compared to drive the motor, in the simulation results. The results satisfactorily demonstrate the advantages of the model-based predictive control to drive this motor, specially due to the constraints treatment.

Space Vector PWM-DTC Strategy for Single-Phase Induction Motor Control

Single-phase induction motors are widely used in fractional and sub-fractional horsepower applications, mostly in domestic and commercial applications such as fans, refrigerators, air conditioners, etc., operating at constant speed or controlled by an on/off strategy which can result in poor efficiency and low-power factor. In terms of construction, these types of motors usually have a main and an auxiliary stator winding, are asymmetrical and are placed 90 degrees apart from each other. The rotor is usually the squirrel-cage type. The asymmetry presented in the stator windings is due to the fact that these windings are designed to be electrically different so the difference between the stator windings currents can produce a starting torque (Krause et al., 1995). Since it has main and auxiliary stator windings, the singlephase induction motor is also known as a two-phase asymmetric induction motor. In recent years, with the growing concern about low-cost operation and the efficient use of energy, the advance in motor drive control technology made it possible to apply these motors to residential applications with more efficiency. Different inverter topologies have been proposed to drive single-phase induction motors, providing ways to save energy. In dos Santos et al. (2010) different ac drive systems are conceived for multiple single-phase motor drives with a single dc-link voltage to guarantee installation cost reduction and some individual motor controls. In Wekhande et al. (1999) and Jabbar et al. (2004), Campos et al. (2007a) and Campos et al. (2007b), two topologies are considered. One is a Half-bridge inverter and the other is a three-leg inverter. The cost difference between the two topologies lays in the fact that the H-bridge inverter needs two large capacitors in the dc link rated for dc link voltage. Also, there is a need of two large resistors connected in parallel with the capacitors to balance the voltage of the capacitors. Despite the fact that the three-leg inverter has more switches, the development of power modules and the need for just one capacitor in the dc link have decreased the topology cost. Along with the reduced cost, a more efficient use of the dc link voltage is achieved. Besides the effort for developing more efficient driving topologies, many strategies to control single-phase motors have been proposed. In Jacobina et al. (1999), rotor-flux control, stator-flux control and direct torque control (DTC) (Takahashi and Noguchi, 1986) are analyzed. The main drawback of the two first strategies is that they use an encoder to obtain