Muawia A. Magzoub

Analysis of Bearing Surface Roughness Defects in Induction Motors

In this paper, a Park’s transformation method for the analysis of various bearing surface roughness defects is presented. The existing instantaneous power analysis and stator current analysis techniques are unable to diagnose bearing surface roughness defects, due to the fact that characteristics defect frequency model is not available for these types of defects. Thus, this paper proposes a Park’s transformation method which can detect surface roughness defects without requiring information of the characteristic defect frequencies. The theoretical and experimental work conducted shows that the proposed method can detect bearing outer and inner race surface roughness faults without use of any extra hardware. The results on the real hardware implementation confirm the effectiveness of the proposed approach.

An Online Fault Diagnosis System for Induction Motors via Instantaneous Power Analysis

ABSTRACT This article aims to provide a new noninvasive method for the online diagnosis of bearing-localized faults under various loading conditions of the induction motors via instantaneous power analysis. The instantaneous noise variations and sensor offsets are considered to be one of the common factors that yield erroneous fault tracking in an online condition monitoring and fault diagnosis system. An adaptive threshold scheme has been designed to tackle the sensor offsets and instantaneous noise variations for reliable decision making on the existence of fault signatures in an arbitrary environment conditions. The performance of the designed threshold scheme has been evaluated on a motor with various bearing defects operating under various loading conditions. Detailed theoretical and experimental evaluations of several bearing-localized faults are presented. The results indicate the viability and effectiveness of the proposed method.

A genetic algorithm optimization of hybrid fuzzy-fuzzy rules in induction motor control

This paper discusses speed control performance of a proposed hybrid fuzzy-fuzzy controller (HFFC) in a variable speed induction motor (IM) drive system. With respect to finding the rule base of the fuzzy controller, a simple genetic algorithm (GA) is employed to resolve the problem of optimization to diminish an objective function, i.e., the Integrated Absolute Error (IAE) criterion. The principle of HFFC is established with the aim of overcoming the shortcoming of the field oriented control (FOC) technique. Simulation results show that HFFC with GA-optimized is the better strategy as compared to HFFC without GA, and conventional hybrid fuzzy-PI controller (HFPIC) for the speed control of IM.

Power system stabiliser for single machine in infinite bus based on optimal control methods

An alternative method for designing a power system stabilizer (PSS) to be used with a single machine and infinite bus system (SMIB) developed on the basis of optimal control (OP) techniques is represented in this paper. The SMIB system is chosen due to simple configuration and useful for understanding the concepts of PSS and its basic effects. The effectiveness of the proposed scheme is tested through simulation to analyse the stability characteristics of the systems small signal about the operating condition at the steady state when a transmission line is lost. The focus of the primary method was on how the control would be performed. This was later proven to possess the responses with shorter settling time and a lower overshoot.

Hybrid fuzzy-fuzzy controller for PWM-driven induction motor drive

This paper represents a method for the designing and developing of a hybrid fuzzy-fuzzy control (HFFC) scheme to gain control over the speed of an induction motor (IM). The fuzzy frequency control and fuzzy current amplitude control are studied in a closed-loop current amplitude input model for an induction motor. A combination of both controllers forms the hybrid controller. The principle of HFFC is to control the rotor speed during acceleration-deceleration stage using fuzzy frequency controller and during steady-state stage using fuzzy stator current magnitude controller to overcome the drawback of field oriented control (FOC) method. The two features (frequency and current) of FOC are employed to design a scalar controller. The software, MATLAB/Simulink is used for the simulation to determine the performance of the controller. A series of tests has been conducted to study the performance of the controller and the results shown that the controller is more reliable and insensitivity to the parameters of the motor changes as compared to the classical indirect field-oriented control (IFOC).

An Optimized Hybrid Fuzzy-Fuzzy Controller for PWM-driven Variable Speed Drives

This paper discusses the performance and the impact of disturbances onto a proposed hybrid fuzzy-fuzzy controller (HFFC) system to attain speed control of a variable speed induction motor (IM) drive. Notably, to design a scalar controller, the two fea‐ tures of field-oriented control (FOC), i.e., the frequency and current, are employed. Specifically, the features of fuzzy frequency and fuzzy current amplitude controls are exploited for the control of an induction motor in a closed-loop current amplitude in‐ put model; hence, with the combination of both controllers to form a hybrid control‐ ler. With respect to finding the rule base of a fuzzy controller, a genetic algorithm is employed to resolve the problem of an optimization that diminishes an objective func‐ tion, i.e., the Integrated Absolute Error (IAE) criterion. Furthermore, the principle of HFFC, for the purpose of overcoming the shortcoming of the FOC technique is estab‐ lished during the acceleration-deceleration stages to regulate the speed of the rotor us‐ ing the fuzzy frequency controller. On the other hand, during the steady-state stage, the fuzzy stator current magnitude controller is engaged. A simulation is conducted via MATLAB/Simulink to observe the performance of the controller. Thus, from a ser‐ ies of simulations and experimental tests, the controller shows to perform consistently well and possesses insensitive behavior towards the parameter deviations in the sys‐ tem, as well as robust to load and noise disturbances.

Managed Pressure Drilling System Using Adaptive Control

The research study that has been presented in this paper depicts automatic control of down whole pressure by topside choking in managed-pressure-drilling (MPD) that is an example of automated drilling and also elaborates automatic control needs for drilling operations. For a set of normal operations, MPD operations require a specified accuracy, including rate changes and set point ramping during connections, swab and surge, as well as certain failure operations namely, gas kicks, blocked choke and power loss. In the future, adaptive control solutions for drilling are anticipated to be extensively used. Furthermore, in this research study, two methods have been implemented for adaptive control for Automatic Managed Pressure Drilling System that are the Massachusetts Institute of Technology (MIT) rule and Lyapunov, and later-on comparison was also conducted between the two. In the end, few viewpoints for the future of intelligent-drilling operations with growing adaptation were also included.

An experimental demonstration of hybrid fuzzy-fuzzy space-vector control on AC variable speed drives

This work presents the experimental demonstration of a hybrid fuzzy-fuzzy controller speed control of a squirrel-cage induction motor variable speed drive based on the space-vector pulse width modulation technique by means of digital signal processing. In particular, two features of field-oriented control were engaged to design a hybrid fuzzy-fuzzy controller, namely the current and frequency. In order to overcome the limitations of the field-oriented control technique, the principle of the hybrid fuzzy-fuzzy controller is introduced in the course of the acceleration–deceleration stages to regulate the speed of the rotor with the help of a fuzzy frequency controller. Conversely, a fuzzy stator current magnitude controller was involved during the steady-state. The results revealed that the control approach has the ability to deliver a practical control solution in the presence of diverse operating conditions.

An approach to diagnose inner race surface roughness defects in bearing of induction motors

In this paper a Parks transformation method for the analysis of bearing inner race surface roughness defects is presented. The existing instantaneous power analysis and stator current analysis techniques are unable to diagnose bearing surface roughness defects, due the fact that characteristics defect frequency model is not available for the bearing surface roughness defects. Thus, this paper proposes a Parks transformation method which can detect surface roughness defects without requiring information of the characteristic defect frequencies. The theoretical and experimental work conducted shows that the proposed method can detect bearing inner race surface roughness faults without use of any extra hardware. The results on the real hardware implementation confirm the effectiveness of the proposed approach.

The effects of internal and external disturbances for the hybrid fuzzy-fuzzy controller applied to IM-drive

This research represents a study of the effects of internal and external disturbances for the developed hybrid fuzzy-fuzzy controller (HFFC) scheme to gain control over the speed of an induction motors (IM) variable speed drive (VSD). In case of an induction motor, the fuzzy current amplitude control and fuzzy frequency control are observed in a closed-loop current amplitude input model. A hybrid controller is formed by a combination of both controllers. In order to overcome a drawback of field oriented control (FOC) method, the principle of HFFC is based on a rule to control a speed of a rotor by utilizing a fuzzy frequency controller during the accelerate-decelerate stage. Whereas, a fuzzy stator current magnitude controller is used during a steady-state stage. The two aspects (current and frequency) of FOC are engaged to design a scalar controller. To observe a performance of a controller, a simulation is carried out by means of software, MATLAB/Simulink. Hence, a performance of a controller is observed by conducting a series of tests, and it has been concluded that a controller is more reliable and shows an insensitive behavior towards the parameter variation in the system and motor robustness to load and noise disturbances.