An implementation of rotor speed observer for sensorless induction motor drive in case of machine parameter uncertainty

The paper describes observers using model reference adaptive system for sensorless induction motor drive with the pulse width modulator and the direct torque control under the circumstances of incorrect information of induction motor parameters. An approximation based on the definition of the Laplace transformation is used to obtain initial values of the parameters. These values are utilized to simulate sensorless control structures of the induction motor drive in Matlab-Simulink environment. Performance comparison of two typical observers is carried out at different speed areas and in presence of parameter uncertainty. A laboratory stand with the induction motor drive and load unit is set up to verify the properties of observers. Experimental results confirm the expected dynamic properties of selected observer

Characterization and snubbing of a bidirectional MCT in a resonant ac link converter

The MOS-Controlled Thyristor (MCT) is emerging as a powerful switch that combines the better characteristics of existing power devices. A study of switching stresses on an MCT switch under zero voltage resonant switching is presented. The MCT is used as a bidirectional switch in an ac/ac pulse density modulated inverter for induction motor drive. Current and voltage spikes are observed and analyzed with variations in the timing of the switching. Different snubber circuit configurations are under investigation to minimize the effect of these transients. The results will be extended to study and test the MCT switching in a medium power (5 hp) induction motor drive

Control of Induction Motor Drive using Artificial Neural Network

The induction motor drive is a dynamic nonlinear system with uncertainty in the machine parameters. The aim of this study is to improve tracking performance of the induction motor drive. A method for controlling induction motor drive is presented with conventional Proportional-Integral (PI) controller and Artificial Neural Networks (ANNs) controller. MATLAB/SIMULINK software is used to develop a three phase induction motor model. Also the performances of the two controllers have been verified. The ANN is trained so that the speed of the drive tracks the reference speed. It is found that with the use of the ANN controller the performance and dynamics of the induction motor are enhanced as compared with that of a conventional PI controller

Artificial intelligence based direct torque control of induction motor drive system

In this project, a three-phase Induction motor (IM) under the direct torque control (DTC) technique is studied. IM is known for its simple engines and its self-starter feature but it always suffered a setback in the area of torque and speed control as it is a highly coupled nonlinear plant and proves to be most complex and expensive speed drive. The application of direct torque control (DTC) is beneficial for fast torque reaction in IM but provide high torque and ripples due to harmonic effects. Thus, the speed control of induction motor is important to achieve maximum torque and efficiency. The aim of this study is to improve tracking performance of the induction motor drive using artificial intelligence control system. A method for controlling induction motor drive is presented with Proportional-Integral (PI) controller and Artificial Neural Networks (ANNs) for performance comparison. MATLAB/SIMULINK software is used to develop a three-phase 2 pole-cage type induction motor model. Also the performances of the two controllers have been verified in terms of its speed and torque responses. The ANN is trained so that the speed of the drive tracks the reference speed. This study proved that the performance and dynamics of the induction motor are enhanced using ANN controller as compared with PI controller

Analysis of coupled and decoupled PWM techniques for induction motor drive

Dual inverter fed induction motor drive-in open-end winding gives more advantages than multilevel inverter fed induction motor drives. For better quality of output voltage with low common mode voltage (CMV), in this paper analysis of coupled and decoupled PWM techniques for open end winding induction motor are carried. The analysis is carried in MATLAB/simulink environment for vector controlled open end winding induction motor drive. The performance of drive and PWM techniques are evaluated both in transient, steady state and loaded conditions

Field Oriented Controlled Speed Sensorless Control of Induction Motors

In this paper, a special class of adaptive control system, model reference adaptive controller (MRAC) for the speed estimation of the field oriented controlled (FOC) induction motor drive is presented. The proposed MRAC is formed using instantaneous and steady-state values of tuning signal insynchronously rotating reference frame, which is a fictitious quantity and has no physical significance. Requirement of no additional sensors makes the drive suitable for retrofit applications. The proposed MRAC-based speed sensorless field oriented controlled induction motor drive estimation technique has been simulated in MATLAB/SIMULIN

Space Vector Based High Performance Discontinuous Pulse Width Modulation Algorithms for VSI Fed AC Drive

This paper presents Space Vector based high performance Discontinuous Pulse width modulation (DPWM) algorithms for VSI fed Induction motor drive. To avoid the complexity due to angle calculation and sector identification involved in Conventional space vector pulse width modulation (CSVPWM), the proposed algorithms use the concept of Imaginary Switching times and a constant variable µ and modulation phase angle δ are used to generate modulating waveforms. The proposed algorithms results in reduced current ripple over CSVPWM. To validate the proposed methods, simulation is carried on V/f controlled Induction Motor drive in MATLAB/SIMULINK environment and the results have been presented. Keywords: CSVPWM, DPWM, Imaginary Switching times, V/f control

High Performance Multicell Series Inverter-Fed Induction Motor Drive

This document is the Accepted Manuscript version of the following article: M. Khodja, D. Rahiel, M. B. Benabdallah, H. Merabet Boulouiha, A. Allali, A. Chaker, and M. Denai, ‘High-performance multicell series inverter-fed induction motor drive’, Electrical Engineering, Vol. 99 (3): 1121-1137, September 2017. The final publication is available at Springer via DOI: https://doi.org/10.1007/s00202-016-0472-4.The multilevel voltage-source inverter (VSI) topology of the series multicell converter developed in recent years has led to improved converter performance in terms of power density and efficiency. This converter reduces the voltage constraints between all cells, which results in a lower transmission losses, high switching frequencies and the improvement of the output voltage waveforms. This paper proposes an improved topology of the series multicell inverter which minimizes harmonics, reduces torque ripples and losses in a variable-speed induction motor drive. The flying capacitor multilevel inverter topology based on the classical and modified phase shift pulse width modulation (PSPWM, MPSPWM) techniques are applied in this paper to minimize harmonic distortion at the inverter output. Simulation results are presented for a 2-kW induction motor drive and the results obtained demonstrate reduced harmonics, improved transient responses and reference tracking performance of the voltage in the induction motor and consequently reduced torque ripplesPeer reviewe

Measurement and reduction of EMI radiated by a PWM inverter-fed AC motor drive system

This paper presents theoretical and experimental relationships in between radiated electromagnetic noises and common-mode and normal-mode currents, paying attention to an induction motor drive system fed by a voltage-source PWM inverter. A method of reducing both the currents is proposed, based on an equivalent model taking parasitic stray capacitors inside an induction motor into account. Electromagnetic interference (EMI) radiated by a 3.7 kW induction motor drive system is actually measured, complying with the VDE 0871 Class A [3m]. Experimental results verify that the combination of the already proposed common-mode transformer and the normal-mode filters being proposed in this paper is a practically viable and effective way to reduce the EMI resulting from both the common-mode and normal-mode currents</p