Haitham Abu-Rub

Predictive current control of voltage-source inverters

A new predictive current controller for a voltage-source inverter is presented in this paper. Practical aspects of realizing the new controller in a system with a digital signal processor (DSP) are considered. Delays introduced by measurements are considered and an improved algorithm with one-period prediction of current is presented. The controller was realized in an experimental system with DSP and field-programmable gate array circuits. Results of the simulations and experiments are presented.

High Performance Control of AC Drives with MATLAB/Simulink Models: Abu-Rub/High Performance Control of AC Drives with MATLAB/Simulink Models

Description: A comprehensive guide to understanding AC machines with exhaustive simulation models to practice design and control Nearly seventy percent of the electricity generated worldwide is used by electrical motors. Worldwide, huge research efforts are being made to develop commercially viable threeand multi-phase motor drive systems that are economically and technically feasible. Focusing on the most popular AC machines used in industry – induction machine and permanent magnet synchronous machine – this book illustrates advanced control techniques and topologies in practice and recently deployed. Examples are drawn from important techniques including Vector Control, Direct Torque Control, Nonlinear Control, Predictive Control, multi-phase drives and multilevel inverters. Key features include: systematic coverage of the advanced concepts of AC motor drives with and without output filter; discussion on the modelling, analysis and control of threeand multi-phase AC machine drives, including the recently developed multi-phase-phase drive system and double fed induction machine; description of model predictive control applied to power converters and AC drives, illustrated together with their simulation models; end-of-chapter questions, with answers and PowerPoint slides available on the companion website company website This book integrates a diverse range of topics into one useful volume, including most the latest developments. It provides an effective guideline for students and professionals on many vital electric drives aspects. It is an advanced textbook for final year undergraduate and graduate students, and researchers in power electronics, electric drives and motor control. It is also a handy tool for specialists and practicing engineers wanting to develop and verify their own algorithms and techniques.

Overview of Space Vector Modulations for Three-Phase Z-Source/Quasi-Z-Source Inverters

Three existing and one extended space vector modulations (SVMs) for the three-phase Z-source/quasi-Z-source inverter (ZSI/qZSI) are investigated. The different switching control patterns, the available maximum shoot-through duty ratio, the maximum voltage stress across the switch versus voltage gain, and efficiency are compared in detail. A total average switch device power taking into account the shoot-through current stress is proposed to evaluate the total stress of power switches. Simulation and experimental results of the prototyped qZSI verify the theoretical analysis. The six parts of shoot-through time intervals will reduce the inductor current ripples, and improve the qZSI efficiency. Also, the maximum voltage stress and total average switch power will benefit from the shoot-through division. However, the division method impacts these performances of qZSI.

Space vector pulse width modulation scheme for three to seven phase direct matrix converter

In this paper a generalized multi-phase space vector theory is considered for developing the space vector modulation of a three-phase to seven-phase direct matrix converter (DMC). The modulation is based on the control of the voltage vectors in the first d-q plane, while imposing the remaining voltage vectors in the second and the third planes (x1-y1, x2-y2) zero. The duty cycles of the bidirectional switches are obtained using space vector modulation theory. The output to input voltage transfer ratio is obtained as 0.7694 for unity input power factor operation. The proposed matrix converter system offers full control of the input power factor, no limitation on the output frequency range and nearly sinusoidal output voltage. The proposed space vector algorithm can be fully implemented on a digital platform. The theoretical analysis is confirmed by digital simulations which is further verified using experimental implementation.

Model predictive control of interleaved boost converters for synchronous generator wind energy conversion systems

Interleaved boost converters are used in multimegawatt wind energy conversion systems with synchronous generators (SG), after a diode rectifier stage to control the generator and provide voltage elevation for the grid connection at lower speeds. The use of a diode rectifier is possible due to the fact SG do not consume reactive power, making it a cost-effective solution to reduce the size and cost of the full-scale converter needed in SG based turbines. This paper proposes a finite control set model predictive control (FCS-MPC) for the interleaved boost converter capable of effectively distributing the power among the different boost channels. In addition, a new strategy to fix the switching frequency is introduced to the predictive control algorithm. A criterion is presented for the design of the weighting factors. The control method has been tested through simulation on a three-channel interleaved boost converter. The steady-state behavior achieved with the proposed method is similar to the one obtained with classic PI control and PWM. This work enables the use of FCS-MPC for interleaved boost converters, to be further included in existing FCS-MPC algorithms for applications where these converters are used, such as SG based wind energy conversion systems, where this control strategy has already been used for the grid side converter.

Variable Speed AC Drives with Inverter Output Filters: Guzinski/Variable Speed AC Drives with Inverter Output Filters

The advance of variable speed drives systems (VSDs) engineering highlights the need of specific technical guidance provision by electrical machines and drives manufacturers, so that such applications can be properly designed to present advantages in terms of both energy efficiency and expenditure.nThis book presents problems and solutions related to inverter-fed electrical motors. Practically orientated, the book describes the reasons, theory and analysis of those problems. Various solutions for individual problems are presented together with the complete design process, modelling and simulation examples with MATLAB/Simulink on the companion website.nA key focus of Variable Speed AC Drives with Inverter Output Filters is to examine the state variables estimation and motor control structures which have to be modified according to the used solution (filter). In most control systems the structure and parameters are taken into account to make it possible for precise control of the motor. This methodology is able to include modifications and extensions depending on specific control and estimation structures.

Shaft misalignment detection using ANFIS for speed sensorless AC drive with inverter output filter

The aim of the paper is to present a diagnostic system for shaft misalignment detection. The diagnostic system is used in an adjustable speed sensorless induction motor (IM) drive with an inverter output filter. A nonlinear control algorithm and state observer were used in the motor control. Because the inverter output filter was installed in the drive, the control structure, as well as the estimation systems, were adequately changed. The adaptive neuro-fuzzy inference system (ANFIS) is used for shaft coupling fault detection. ANFIS is based on the analysis of the stator current, motor speed, and load torque processing. ANFIS uses only signals estimated from the state observers whereas observers calculate required variables only on the base of the inverter input voltage and two output current sensors. No additional special sensors are required. The proposed diagnostic system clearly indicates the shaft misalignment. The paper presents the model of the drive, control and estimation algorithms, as well as the diagnostic system. Whole drive and ANFIS fault indicator were verified by experiments for a 1.5 kW induction motor drive system.

States and parameters estimation in induction motor using Bayesian techniques

This paper addresses the problem of rotor speed, flux and parameters estimation of induction motor on the basis of a three-order electrical model. Thus, we propose to use a particle filtering (PF) to estimate states and parameters for an induction motor. It is assumed that only the voltages stator currents are measurable. In addition, the rotor resistance and magnetizing inductance, which vary with the motor temperature and magnetization level, can also be estimated within the same framework. Hence, the objective of this work is to estimate three states (the rotor speed, the rotor flux, and the stator flux) and two parameters (the rotor resistance and the magnetizing inductance). Simulation analysis demonstrates that the Bayesian algorithm can well estimate the states/parameters under disturbs of the noise, and it provides efficient accuracies for the states estimation. In addition, detailed case studies show that Bayesian algorithm has advantages over Unscented Kalman filter (UKF) for highly nonlinear estimation problems. Evaluation of the methods was performed by using Root Mean Square Error.

Estimation of nonlinear control parameters in induction machine using particle filtering

In this paper, particle filtering (PF) is addressed for both estimation and control to be integrated into a unified closed-loop or feedback control system that is applicable for a general family of nonlinear control structures. In the current work, the state variables (the rotor speed, the rotor flux, and the stator flux) as well as the model parameters are simultaneously estimated from noisy measurements of these variables, and the estimation technique is evaluated by computing the estimation root mean square error (RMSE) with respect to the noise-free data. In this case, in addition to comparing the performances of the estimation, the effect of the number of estimated model parameters on the accuracy and convergence of this technique is also assessed. Simulation analysis demonstrates that the particle filter can well estimate the states/parameters under disturbs of the noise, and it provides efficient accuracies for the states estimation.

Speed Sensorless AC Drive with Inverter LC Filter and Fault Detection Using Load Torque Signal

The industrial development in recent years has seen a major increase in the use of induction motors, whereby the cost has to be as lownas possible and the lifetime as long as possible. To follow up this desire, investigations in this area have become very intense. For that reason, thisnpaper presents a solution for driving an induction motor and simultaneous fault detection with no need for additional sensors. In order to achieve thisntarget, an observer system is implemented and a torque estimation procedure is used for torque detection. An LC filter was installed at the inverternoutput to provide better THD of the current. The validation of the drive operation was achieved through simulation and experiments. To investigatenpossible faults, an artificial unbalance was introduced to the test bench, whereby the experiment was validated by a comparison of physicalnvibrations and estimated torque.