Principle Of Field Oriented Control Research Articles

Alternating Current Electric Generator Machine Inverters in a Parallel Power Sharing Connection

This paper covers the theoretical background as well as chosen selected experimental results obtained for two AC current generators connected to voltage source inverters working in parallel. Inverters were connected in parallel via their intermediate direct current circuits by means of auctioneering diodes which select higher voltage source, and then directly to a DC power network. The selected real-time control algorithm for a digital signal processor and a field programmable gate array was used to achieve the proper excitation of two different types of alternators: a squirrel-cage generator denoted as and a self-excited synchronous generator. Another task for the excitation system was to maintain the proper level of direct current link voltage and stable power distribution between both generators rotating at changing speeds. The windings of alternators were fed with the use of so-called machine side inverters. The asynchronous generator was a voltage source inverter driven with the use of a sensorless multiscalar algorithm based on the current machine model, whereas the self-excited synchronous generator worked on the field oriented control principle. To prove the robustness of the chosen algorithm, different types of load were applied while during the parallel work of the generators and inverters.

Field Oriented Control Principles for Synchronous Motor

Field Oriented Control Principles for Synchronous Motor

Modeling of a Compressed Air Energy Electrification by Using Induction Generator Based on Field Oriented Control Principle

The objective of this paper is to propose a modelling of a small compressed air energy storage system, which drives an induction generator based on a field-oriented control (FOC) principle for a renewable power generation. The proposed system is a hybrid technology of energy storage and electrification, which is developed to use as a small scale of renewable energy power plant. The energy will be transferred from the renewable energy resource to the compressed air energy by reciprocating air compressor to be stored in a pressurized vessel. The energy storage system uses a small compressed air energy storage system, developed as a small unit and installed above ground to avoid site limitation as same as the conventional CAES does. Therefore, it is suitable to be placed at any location. The system is operated in low pressure not more than 15 bar, so, it easy to available component in country and inexpensive. The power generation uses a variable speed induction generator (IG). The relationship of pressure and air flow of the compressed air, which varies continuously during the discharge of compressed air to drive the generator, is considered as a control command. As a result, the generator generates power in wide speed range. Unlike the conventional CAES that used gas turbine, this system does not have any combustion units. Thus, the system does not burn fuel and exhaust pollution. This paper expresses the modelling, thermodynamic analysis simulation and experiment to obtain the characteristic and performance of a new concept of a small compressed air energy storage power plant, which can be helpful in system designing of renewable energy electrification. The system was tested under a range of expansion pressure ratios in order to determine its characteristics and performance. The efficiency of expansion air of 49.34% is calculated, while the efficiency of generator of 60.85% is examined. The overall efficiency of system of approximately 30% is also investigated.

A New Wavelet-based Speed Controller for Induction Motor Drives

This article presents a novel speed controller based on multi-resolution decomposition analysis of the discrete wavelet transform for vector-controlled induction motor drives. The field-oriented control principle is used to decouple the flux and torque components of the induction motor dynamics. In the proposed controller, the discrete wavelet transform is used to decompose the speed error between the actual and command speeds at various scales. The control signal is generated using the wavelet-transformed coefficients of speed error of different scales. It has been found that these coefficients can represent the cumulative effect of motor drive uncertainties such as parameter variations, measurement noise, frictional variation, and external torque disturbances. The performance of this controller is evaluated in both simulation and experiments. The complete vector-control scheme incorporating the proposed controller is successfully implemented in real time using the ds1102 digital signal processor board (dSPACE, GmbH, Paderborn, Germany) for the laboratory 1-hp induction motor. The experimental results validate the robustness and, hence, justify the applicability of the proposed controller for the induction motor drive to be used in high-performance drive applications. In order to prove the superiority of the proposed controller, a comparison between the proposed and the conventional proportional-integral and proportional-integral-derivative controller-based systems is made at different dynamic operating conditions.

Sistema de acionamento com motor de indução orientado indiretamente pelo campo com adaptação MRAC da velocidade

Este artigo investiga o uso da estratégia de controle adaptativo do tipo modelo de referência para sistemas de acionamentos de motores de indução com o controle orientado indiretamente pelo campo. O esquema proposto não requer o uso de nenhum sensor eletromecânico e é praticamente independente da constante de tempo rotórica. Por exemplo, este esquema é bem adequado para aplicações onde não há controle de velocidade, mas é necessário manter o controle com orientação indireta pelo campo sintonizado para se obter controle de conjugado com alto desempenho. A sensibilidade paramétrica do esquema de controle à variações em r s e sigmal s também é investigada no artigo. Os resultados experimentais apresentados demonstram o perfeito funcionamento do esquema proposto.

Field-oriented control of an induction motor using random pulsewidth modulation

The principle of field-oriented control (FOC) is a well-established means to obtain a high-performance drive, but the de facto standard FOC does not solve an important secondary problem for inverter-fed motors-the acoustic noise emitted from the motor is tonal due to the constant switching frequency operation. This may be very annoying, even if the exposure time is short. From this background, this paper proposes a classic FOC synchronized to a current-controlled pulsewidth modulation inverter operating with a random switching frequency. This implies that the sampling frequency of both the current controller and the flux estimator is nonuniform, but nevertheless, it is shown that the good dynamic response inherited from the FOC can be maintained while lowering the subjective acoustic annoyance to a great extent due to the random switching frequency operation. Besides laboratory test results documenting the dynamic and steady-state characteristics of the proposed system, design considerations are presented.

Field-oriented control of induction motors using neural-network decouplers

This paper presents a novel approach to the field-oriented control (FOC) of induction motor drives. It discusses the introduction of artificial neural networks (ANNs) for decoupling control of induction motors using FOC principles. Two ANNs are presented for direct and indirect FOC applications. The first performs an estimation of the stator flux for direct field orientation, and the second is trained to map the nonlinear behavior of a rotor-flux decoupling controller. A decoupling controller and flux estimator were implemented upon these ANNs using the MATLAB/SIMULINK neural-network toolbox. The data for training are obtained from a computer simulation of the system and experimental measurements. The methodology used to train the networks with the backpropagation learning process is presented. Simulation results reveal some very interesting features and show that the networks have good potential for use as an alternative to the conventional field-oriented decoupling control of induction motors.

FIELD-ORIENTED CONTROL OF INDUCTION MACHINES IN THE PRESENCE OF MAGNETIC SATURATION

ABSTRACT This paper presents derivation of the equations which describe field-oriented control of saturated induction machines. Field-oriented control principles are applied on the saturated model of induction machine and new equations are obtained, which differ significantly from the well-known model valid when the main flux saturation is absent or neglected. Rotor flux oriented control of voltage-fed and current-fed saturated induction machines is discussed. New decoupling circuits which are needed under saturated conditions are presented. Simulation results, which show the influence of main flux saturation on transient behaviour of the drive and which verify the theoretical results are included.