ROBUST FAULT ANALYSIS FOR PERMANENT MAGNET DC MOTOR IN SAFETY CRITICAL APPLICATIONS

Robust fault analysis (FA) including the diagnosis of faults and predicting their level of severity is necessary to optimise maintenance and improve reliability of Aircraft. Early diagnosis of faults that might occur in the supervised process renders it possible to perform important preventative actions. The proposed diagnostic models were validated in two experimental tests. The first test concerned a single localised and generalised roller element bearing fault in a permanent magnet brushless DC (PMBLDC) motor. Rolling element bearing defect is one of the main reasons for breakdown in electrical machines. Vibration and current are analysed under stationary and non-stationary load and speed conditions, for a variety of bearing fault severities, and for both local and global bearing faults. The second test examined the case of an unbalance rotor due to blade faults in a thruster, motor based on a permanent magnet brushed DC (PMBDC) motor. A variety of blade fault conditions were investigated, over a wide range of rotation speeds. The test used both discrete wavelet transform (DWT) to extract the useful features, and then feature reduction techniques to avoid redundant features. This reduces computation requirements and the time taken for classification by the application of an orthogonal fuzzy neighbourhood discriminant analysis (OFNDA) approach. The real time monitoring of motor operating conditions is an advanced technique that presents the real performance of the motor, so that the dynamic recurrent neural network (DRNN) proposed predicts the conditions of components and classifies the different faults under different operating conditions. The results obtained from real time simulation demonstrate the effectiveness and reliability of the proposed methodology in accurately classifying faults and predicting levels of fault severity.the Iraqi Ministry of Higher Education and Scientific Researc

Performance analysis of electric drives using slotless motors

La tesi descrive le principali criticità nel controllo di macchine elettriche di tipo 'slotless'; con particolare riguardo alle prestazione della macchina stessa in relazione alle tecniche di controllo utilizzate (SVM o controllo trapezoidal e)

Implementation,Simulation of Four Switch Converter Permanent Magnet Brushless DC Motor Drive for Industrial Applications

This Research paper proposes a low cost four switch three phase inverter (FSTPI) fed brushless DC (BLDC) motor drive for Active power factor correction for residential applicationswith out environmental issues. This proposed system is simplified the topological structure of the conventional six switch three phase inverter (SSTPI) and includes an active power factor correction in front end rectifier which results in sinusoidal input current and it closed to unity power factor. In this project a new structure of four switch three phase inverter with reduced number of switches for system is introduced. This system consists of single phase rectifier and four switch three phase inverter. This proposed inverter fed BLDC motor used in Sensorless control schemes. To improve sensorless control performance, six commutation modes based on direct current controlled PWM scheme is implemented to produced the desire Torque-Speed characteristics. This four switch three phase inverter is achieved by the reduction of switches, low cost control and saving of hall sensor. The design and implementation of low cost four switch inverter for Brushless motor drive with active power factor correction  have been conducted successfully and valediction  of the proposed sensorless control for four switch three phase inverter fed BLDC motor drive is developed and analysed using both  MATLAB/SIMULINK and hardware results  are verified out successfully

Kinetic energy recovery system design and control of the braking vehicle system

This PhD thesis presents a simulation of the dynamic energy recovery with an experimental-based model of the braking process. Accordingly, it describes the steps taken to develop a small-scale representation of the designed testing equipment, which was built within the laboratory boundaries to simulate the natural system. Moreover, it demonstrates the experimental probing and mathematical modelling of the system from an electronic perspective as well as in the mechanical perception as ready-made (black box) models. Meanwhile, the designed system shows an accurate representation in simulation, which was verified experimentally. In this study, energy recovery with two distinct storage units, especially, ultra-capacitors (UCs) and battery energy storage systems (ESS) was considered as an alternative energy source with propulsion strategies to assess their effect on storing and generating electricity from the braking process. A simulation was determined to signal the system behaviour for different operating scenarios. Consequently, the voltage generated by a permanent magnet brushless direct current (PMBLDC) motor of the test network, when used as a generator in the braking operation, was used to study the impact of the uncontrolled charging loads (batteries and UCs) on the system performance in the braking process. Furthermore, this research has proposed a new paradigm and regenerative braking (RB) algorithm. Taking the necessary information about the system from the flow rate correlated with two connected reservoirs to represent the charge flow rate in the RB mechanism. The dual tank's design was developed and used to describe the UCs’ and the generator as a storage model. The variable generated voltage during the landing and braking process determines an important term, which is the generator capacity concerning the UCs’ capacity. While modelling and analysis were primarily based on experimental results, many cases were examined to manage the best representation of the design. The outcomes were identified and discussed for both energy recovery II and downtime, which satisfy the design requirements and provide an accurate result regarding system performance