Investigation of slim type BLDC motor drive with torque ripple minimization using abridged space-vector PWM control method

Abstract: Brushless DC (BLDC) motors are becoming an increasingly popular motor of choice for its unique characteristics. The BLDC motor drive is assumed to have trapezoidal back-electromotive force (EMF), rectangular phase currents and together produces the desired torque. However, practical back-EMF waveform might not be exactly trapezoidal because of current ripple, design considerations and manufacturing limitations. The adverse effect is the torque ripple generated due to the current ripple that causes mechanical vibration, acoustic noise and affects the accuracy of speed and position control which is not desirable in motor operation. In this paper an algorithm is developed to control and minimize the generated torque ripple using Space Vector Pulse Width Modulation (SVPWM) scheme. The efficiency improvement of slim type BLDC motor is confirmed using MATLAB environment and low cost TI Piccolo F28035 microcontroller (MC)

Development of Double-Sided Interior Permanent Magnet Flat Linear Brushless Motor and Its Control Using Linear Optical Potentiometer

A new 6/4 double-sided interior permanent-magnet (IPM) flat linear brushless motor (IPM-FLBM) and novel optical potentiometer mechanism for a linear motion-control system are presented in this dissertation. For this purpose, new detent-force-minimization methodologies for the IPMFLBM are studied on the basis of the superposition principle. The end-effect force is reduced by a new two-dimensional optimization using the step-shaped end frames. The cogging force is minimized through a destructive interference using the slot-phase shift between the upper and lower stators. A base model prototype with the detent force of only 1.5% of the maximum thrust force is developed using the electrical solid steel. Analytic modeling techniques of the base model prototype with slot-phase shift and alternate teeth windings are investigated. A variable winding function is newly developed to evaluate the inductances of the salient motor with the alternate teeth windings. The steady-state thrust force is modeled for this linear brushless AC (BLAC) motor. Their validities are demonstrated experimentally. The electromagnetic and steady-state performance analyses of a new prototype using a soft magnetic composite (SMC) material are also studied using a simplified nonlinear magnetic equivalent circuit (MEC) analysis. Its iron and copper losses are investigated in terms of the thermal limitation. The feasibility of the IPM-FLBM using the SMC material is demonstrated through the comparisons of the average steady-state thrust and ripple forces for these two prototype linear motors. A novel low-cost high-precision absolute displacement-sensing mechanism using optoelectronic components is developed. The working principle that is based on the change of the optical power that is reflected off the monotone-colored pattern track from a light emitting diode (LED) to a red-green-blue (RGB) photo diode (PD) is presented. The performance of the proposed optical potentiometer (OP) mechanism is verified by the bandwidth (BW) of 4.42 kHz and nonlinearity of 2.8% are achieved. A novel low-ripple 12-step current control scheme using a single current sensing resistor is developed using the six Hall-effect sensors for the force control of the IPMFLBM. Its performances are experimentally verified and compared with a conventional field-oriented control (FOC) scheme. In the end, the position-control loop, which includes the 12-step current control loop, double-sided IPM-FLBM, and linear optical potentiometer (LOP), is designed using a proportional controller with a lead compensator. The performances of the linear motion-control system are demonstrated through the various experiments in the time and frequency domains

Investigation of Doubly Salient Stator Slot Permanent Magnet Machines

Variable flux reluctance machines (VFRMs), which have both field and armature windings on the stator, are novel types of magnetless machines with a simple and robust mechanical structure and a low manufacturing cost. However, their electromagnetic performance, especially their overloading capability, is limited by high magnetic saturation due to field excitation. Therefore, circumferentially magnetized permanent magnets (PMs) are placed in the stator slot openings in order to (a) alleviate the magnetic saturation and (b) increase the torque capability based on VFRM, which leads to novel machine topologies, i.e. hybrid excited stator slot PM machines (HESSPMs) and stator slot PM machines (SSPMs). The effects of PMs in the stator slot openings are comparatively investigated for VFRMs, HESSPMs and SSPMs together with the discussion of the unique fault tolerant feature in stator slot PM machines. Furthermore, the overlapping winding (OW) layouts with coil pitches of 3 stator slot pitches are proposed in the three machine topologies in order to enhance the torque density. The electromagnetic performance of each machine topology, with OW and non-overlapping winding (NOW) and various feasible stator slot/rotor pole number combinations, is comparatively studied by finite element method. It shows that the proposed OW layout can improve the average torque of VFRM, HESSPM and SSPM with the optimal stator/rotor pole number combination. The proposed OW layout will be more competitive for the machines with a longer axial length and reduced end-effect. Prototype machines for these three machine topologies with both NOW and OW are built and tested to validate the finite element predicted results

44th Aerospace Mechanisms Symposium

The Aerospace Mechanisms Symposium (AMS) provides a unique forum for those active in the design, production and use of aerospace mechanisms. A major focus is the reporting of problems and solutions associated with the development and flight certification of new mechanisms

Permanent magnet synchronous machine drive system with variable DC bus for EV regenerative braking

Orientador: José Antenor PomilioDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: Este trabalho aborda o acionamento da máquina síncrona de magnetos permanentes em um sistema com frenagem regenerativa. O controle da máquina é realizado por orientação de fluxo e possui observadores para estimar a posição e a velocidade angular do rotor. O sistema de armazenamento de energia é uma topologia híbrida bateria/capacitor. A alimentação do inversor é fornecida por um barramento CC de tensão controlada por um conversor CC/CC elevador de tensão. Esse conversor é controlado por malhas aninhadas de corrente no indutor e tensão no capacitor, que determinam o fluxo de energia entre os sistemas de armazenamento. A referência da tensão CC é uma função da velocidade do rotor e possibilita que o capacitor forneça e absorva energia da máquina. O dimensionamento do capacitor do barramento CC e a administração de energia faz com que picos de potência na bateria sejam atenuados durante as acelerações e as desaceleraçõesAbstract: his work adresses the driving of a permanent magnet synchronous machine in a system with regerative braking. The machine control is done by flux orientation and has observers for estimation of the rotor position and speed, needed in this control. The energy storage system is a hybrid topology battery/capacitor. The feeding of the inverter is supplied by the DC link that is controlled by a DC/DC boost converter. The converter control is executed by nested loops of inductor current and capacitor voltage that manages the energy flow between the storage systems. The DC voltage reference proposed is a function of the machine speed and it allows the DC link capacitor to supply and absorb kinetic energy from the machine. The sizing of the DC link capacitor and the energy managing makes the power peaks, in the battery, lower during the accelerations and the brakingsMestradoEnergia EletricaMestre em Engenharia Elétrica1490992CAPE

ESSE 2017. Proceedings of the International Conference on Environmental Science and Sustainable Energy

Environmental science is an interdisciplinary academic field that integrates physical-, biological-, and information sciences to study and solve environmental problems. ESSE - The International Conference on Environmental Science and Sustainable Energy provides a platform for experts, professionals, and researchers to share updated information and stimulate the communication with each other. In 2017 it was held in Suzhou, China June 23-25, 2017

Personality Identification from Social Media Using Deep Learning: A Review

Social media helps in sharing of ideas and information among people scattered around the world and thus helps in creating communities, groups, and virtual networks. Identification of personality is significant in many types of applications such as in detecting the mental state or character of a person, predicting job satisfaction, professional and personal relationship success, in recommendation systems. Personality is also an important factor to determine individual variation in thoughts, feelings, and conduct systems. According to the survey of Global social media research in 2018, approximately 3.196 billion social media users are in worldwide. The numbers are estimated to grow rapidly further with the use of mobile smart devices and advancement in technology. Support vector machine (SVM), Naive Bayes (NB), Multilayer perceptron neural network, and convolutional neural network (CNN) are some of the machine learning techniques used for personality identification in the literature review. This paper presents various studies conducted in identifying the personality of social media users with the help of machine learning approaches and the recent studies that targeted to predict the personality of online social media (OSM) users are reviewed

Massachusetts Domestic and Foreign Corporations Subject to an Excise: For the Use of Assessors (2004)

International audienc