Manoel L. Aguiar

Extended DQ Transformation for Vectorial Control Applications of Non-sinusoidal Permanent Magnet AC Machines

This paper presents an extended dq transformation model of non-sinusoidal permanent magnet synchronous machines (SM-PMSM). This transformation permits to obtain a simpler electromagnetic torque equation for this type of machine. The resultant electromagnetic torque equation obtained from this model is directly proportional to the machine quadrature stator current. Initially, the three-phase equations of the motor are presented. These equations are widely used for sinusoidal permanent magnetic machines, as well as for non-sinusoidal ones. The well known vectorial model for sinusoidal PM machines is shown. Then, a vectorial model for a non-sinusoidal PM machine is presented and the proposed vectorial model with variable dq axis magnitude is developed. Simulation results of the electromagnetic torque, produced by a brushless DC drive system using conventional six step open loop control are presented. These results are compared with those produced by the same system using the proposed model into an open loop system and into a closed loop system

Magnetic Field Analysis of a Brushless DC Motor Comparing Ferrite and NdFeB Magnets on Rotor

This paper presents comparisons between three-phase permanent-magnet motor with ferrite magnets on rotor and other with NdFeB (bonded). Related to this replacement, the advantages and disadvantages are quoted. The analysis of magnetic field is made through the finite element method. The used machine has nonsinusoidal flux. Its application main is in hermetic compressor household refrigeration systems. Also, the geometric and magnetic characteristics are presented.

Simulation of DTC Strategy in VHDL Code for Induction Motor Control

This paper presents a simulation of direct torque control (DTC) strategy, used to control induction motors. This simulation was realized with Matlab and Modelsim programs. The Matlab/Simulink was used to simulate the motor dynamics and the inverter of the control system. The DTC strategy was executed in Modelsim using VHDL floating point

Chopper-controlled PMDC motor drive using VHDL code

In many industrial applications it is necessary to convert a constant-voltage dc (direct current) source into a variable-voltage/variable-current source for the speed control of the dc motor drive. The variable dc voltage is controlled by chopping the input voltage by varying the on and off times of a converter, and the type of converter capable of such a function is known as a chopper. This work presents a chopper control using VHDL (very high speed integrated circuit hardware description language - VHSIC-HDL) language to control a PMDC motor (permanent magnetic direct current). The simulation is performed using two programs: MATLAB/Simulink and ModelSim, working in a co-simulation mode, provided by Link for ModelSim toolbox from Simulink. While the motor and inverter dynamics is performed in MATLAB, the control algorithm of the chopper runs in the ModelSim program. The simulation results are presented and analyzed in this work.

Harmonic Detection Based on Artificial Neural Networks for Current Distortion Compensation

In this paper a method for the determination of part of the current harmonic components for the selective compensation harmonic by single-phase active power filter is presented. The non-linear load is composed by an AC controller with variable resistive load. The first six components are identified through artificial neural network. The effectiveness of the proposed method and its application in the single-phase active power filters with selective harmonic compensation are verified. Simulation results are presented to validate the proposed approach.

Improved Sensorless Vector Control of Induction motor Using Sliding Mode Observer

This work deals with a sensorless speed control for three-phase induction motor in order to improve its operation at low speed. Initially, a direct field oriented control employing space vector pulse with modulation based on sliding mode observer (SMO) is studied and evaluated due to its high accuracy in estimating the flux at low speed. The proposed current model based on SMO provides good speed estimation under low speed and parameter or load changes. Simulations and experimental tests with diferent operational conditions at low speed are carried out in order to test the sensorless control. The results show a good perfomance and agreed with the results shown in recent papers.

Strategy to Control the Terminal Voltage of a SRG Based on the Excitation Voltage

Since the power demand is increasing through out the decades, recent researches on electrical generator topologies have been developed. The switched reluctance generator has been pointed out as a great choice since it shows a simple structure, robustness and low cost. In order to be driven properly, there are some control technics that allow stable voltage values when the power system suffers disturbances during its operation. This work deals with a Fuzzy voltage controller for a switched reluctance generator. Simulations and experimental results have been carried out in order to evaluate the control robustness and their results are presented in this paper.

A Rapid Prototype Design to Investigate the FPGA-Based DTC Strategy Applied to the Speed Control of Induction Motors

This work presents a virtual prototype for study and simulation of DTC technique applied to the speedy control of induction motor. The implementation is supposed to be realized in a FPGA device. The simulation was conducted using the Matlab/Simulink and the ModelSim programs. While the inverter/motor dynamics is executed in the Matlab, the ModelSim perform the speed control and the DTC procedure witch is written in VHDL-code. The both programs work in co-simulation mode provided by the Link-for-ModelSim toolbox in the Simulink. This virtual prototype was tested with the implementation of the DTC strategy using float point representation.

Implementation of a Non-Sinusoidal Permanent-Magnet Synchronous Machine Vectorial Control

This paper shows the results of the implementation of a proposed vectorial model for non-sinusoidal air-gap magnetic flux density distribution permanent-magnet synchronous machines (SM-PMSM). This work shows a comparison between this kind of machine fed by a conventional six-step 120deg inverter and an inverter with the proposed non-sinusoidal vectorial machine model. The same machine is fed by these two kinds of converter in a positioning drive system of a machine-tool application, both in similar situations. The results of rotor position are shown for those two situations, showing the effect of electromagnetic torque ripple in rotor position, consequently, in tool positioning. This same machine was submitted to a traction application and was fed by the converter employing non-sinusoidal vectorial machine model. The measured stator currents and simulation results were compared in similar situations

Integral sliding mode controller with anti-windup method analysis in the vector control of induction motor

This work presents an integral sliding mode controller, applied to the three-phase induction motor IM using indirect field oriented control technique. Besides seeking high dynamic performance using the slinding mode controller, it is discussed the necessity of a parametric action control (known as equivalent control) to turn the system stable. To do so, it is used an integral sliding mode controller with anti-windup method. The motor performance is verified by means of numeric simulations and experimental tests with load disturbances.