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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Modul pro řízení DC motorů / Module for control DC motors

Fojt, Bohumil January 2010 (has links)
Subjects this diploma thesis is positional DC motor control with personal designed electronics. Main body the diploma thesis was meet principle DC motor control. Further purposes was apprise of principle signal analyse from rotary incremental sensor and implementation design electronics for positional DC motor control.
52

Algoritmy pro řízení elektrických motorů / Algorithms for electrical motor control

Lyko, Antonín January 2017 (has links)
This paper presents the structure and basic elements of the Autosar software architecture. In addition, the configuration code generation options are presented for both MC-ISAR drivers and AURIX TriCore TC277 hardware modules using EB tresos Studio. For the purpose of possible integration of the electric motor control algorithms, configurations of the GTM and VADC hardware modules have been created and described to enable the generation of PWM signals along with synchronously triggered parallel analogue-to-digital conversions. For this purpose, an application interface including the PWM driver was also developed and described.
53

Zigbee based wireless adjustable speed drive system

Moghe, Prajakta S. January 2016 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / This thesis proposes a remotely controlled motor drive system which is able to supply a regulated voltage for both DC and AC motors. The proposed system integrates two different technologies, each of which belongs to the field of wireless communications and semiconductor power electronics. The introduction highlights the literature review and technical contributions in these two electrical engineering fields. The pulse width modulated control algorithm for speed control is discussed in detail. Incorporating the zigbee wireless technology into the motor drive system, for the speed control of an AC and a DC motor, by implementing digital pulse width modulation technique is the aim of this thesis. The main characteristics of the proposed system are: 1) its universal feature since it can feed either DC or AC motor without changing the hardware, 2) remotely controlled, which allows the end-user to control the motor speed safely from a remote distance, 3) flexibility in installation of the motor drives in areas that are not easily accessible by end-users, and 4) uninterrupted speed control for distance of up to few 100 feet.
54

Design and Implementation of Sensing Methods on One-Tenth Scale of an Autonomous Race Car

Veeramachaneni, Harshitha 12 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Self-driving is simply the capacity of a vehicle to drive itself without human intervention. To accomplish this, the vehicle utilizes mechanical and electronic parts, sensors, actuators and an AI computer. The on-board PC runs advanced programming, which permits the vehicle to see and comprehend its current circumstance dependent on sensor input, limit itself in that climate and plan the ideal course from point A to point B. Independent driving is not an easy task, and to create self-sufficient driving arrangements is an exceptionally significant ability in the present programming designing field. ROS is a robust and versatile communication middle ware (framework) tailored and widely used for robotics applications. This thesis work intends to show how ROS could be used to create independent driving programming by investigating self-governing driving issues, looking at existing arrangements and building up a model vehicle utilizing ROS. The main focus of this thesis is to develop and implement a one-tenth scale of an autonomous RACECAR equipped with Jetson Nano board as the on-board computer, PCA9685 as PWM driver, sensors, and a ROS based software architecture. Finally, by following the methods presented in this thesis, it is conceivable to build an autonomous RACECAR that runs on ROS. By following the means portrayed in this theory of work, it is conceivable to build up a self-governing vehicle.
55

Electro-Thermal Dynamics and the Effects of Generalized Discontinuous Pulse Width Modulation Algorithms on High Performance Variable Frequency Drives

Krohn, Austin Bengoechea 05 September 2014 (has links)
No description available.
56

Output Impedance in PWM Buck Converter

Cazzell, Gregory A. 27 July 2009 (has links)
No description available.
57

Steady-State and Small-Signal Modeling of a PWM DC-DC Switched-Inductor Buck-Boost Converter in CCM

Lee, Julie JoAnn 16 July 2012 (has links)
No description available.
58

Análisis y reducción de la distorsión para técnicas de modulación de pulsos

Chierchie, Fernando 17 February 2016 (has links)
La modulación digital por ancho de pulso (PWM por sus siglas en inglés) utilizada en amplificadores conmutados convierte las muestras de una se˜nal discreta en una señal binaria compuesta por pulsos de ancho variable que posee intrínsecamente altos niveles de distorsión en banda base. En esta tesis se estudian y proponen técnicas de modulación digital de tiempo real que presentan muy baja distorsión incluso cuando se utilizan frecuencias de conmutación de apenas el doble de la máxima frecuencia de la señal moduladora. Se obtiene un modelo discreto no lineal de la modulaci´on PWM que captura en forma precisa el comportamiento de la modulación en banda base, desde frecuencia cero hasta la mitad de la frecuencia de conmutación. El modelo se extiende para modelar también otros fenómenos prácticos como variaciones en la amplitud de los pulsos y corrimientos en los flancos ascendentes y descendentes de la señal PWM. Una serie de simplificaciones permite obtener modelos basados en estructuras tipo Hammerstein generalizadas conformadas por la conexión paralela de potencias y filtros lineales que modelan la din´amica del modulador. Utilizando estos modelos se desarrollan algoritmos digitales que permiten determinar los ciclos de trabajo de la señal PWM a partir de las muestras de la señal de entrada garantizando distorsión nula de la señal PWM en banda base. Un modulador basado en el método iterativo de Newton permite obtener una estructura sencilla capaz de ser implementada en tiempo real en procesadores digitales de señales. Este modulador se extiende para compensar variaciones en las amplitudes de los pulsos. Se presenta también otro método de modulación basado en una estructura de predistorsión adaptiva conocida como arquitectura de aprendizaje indirecto que estima la inversa del modelo de la modulación PWM utilizando un algoritmo de cuadrados mínimos recursivo. Estos métodos de modulación junto con otro método basado en una inversa de Volterra se comparan en diferentes condiciones de operaci´on mediante simulaciones y mediciones experimentales a partir de implementaciones en tiempo real y utilizando procesadores digitales de señales. / Digital pulse width modulation (PWM) used in switched amplifiers converts samples of a discrete-time signal into a binary signal composed of pulses of variable width, introducing high levels of baseband distortion. In this thesis real-time digital PWM modulators having very low distortion even when the switching frequency is just twice the maximum frequency of the modulating signal are presented. A nonlinear discrete-time model capturing in detail the baseband behavior (from zero Hertz to half the switching frequency) of the PWM modulator is developed. The model is extended to model other practical phenomena such as variations in the amplitude of the pulses and shifts in the switching times (rising and falling edges of the PWM signal). A number of simplifications allows to obtain a generalized Hammerstein structure composed of the parallel connection of power and linear filters which models the dynamics of the system. Using this model, modulation algorithms to determine the duty cycle of the PWM signal from the samples of the input signal ensuring zero baseband distortion are developed. A modulator based on the Newton iterative method, enables a simple structure that can be implemented in real time on digital signal processors. This modulator is extended to compensate for variations in the amplitudes of the pulses. Another modulation method based on an structure known as indirect learning architecture that estimates an inverse model of PWM modulator using a recursive least squares algorithm is also presented. These modulation algorithms and another method based on Volterra inverse are compared in different operating conditions through simulations and experimental measurements from a real-time implementation using digital signal processors.
59

Cascade Dual-Buck Inverters for Renewable Energy and Distributed Generation

Sun, Pengwei 16 April 2012 (has links)
Renewable energy and distributed generation are getting more and more popular, including photovoltaic modules (PV), wind turbines, and fuel cells. The renewable energy sources need the power electronics interface to the utility grid because of different characteristics between the sources and the grid. No matter what renewable energy source is utilized, inverters are essential in the microgrid system. Thanks to flexible modular design, transformerless connection, extended voltage and power output, less maintenance and higher fault tolerance, the cascade inverters are good candidates for utility interface of various renewable energy sources. This dissertation proposes a new type of cascade inverters based on dual-buck topology and phase-shift control scheme. Compared to traditional cascade inverters, they have enhanced system reliability thanks to no shoot-through problems and lower switching loss with the help of using power MOSFETs. With phase-shift control, it theoretically eliminates the inherent current zero-crossing distortion of the single-unit dual-buck type inverter. In addition, phase-shift control can greatly reduce the ripple current or cut down the size of passive components by increasing the equivalent switching frequency. An asymmetrical half-cycle unipolar (AHCU) PWM technique is proposed for dual-buck full-bridge inverter. The proposed approach is to cut down the switching loss of power MOSFETs by half. At the same time, this AHCU PWM leads to current ripple reduction, and thus reducing ripple-related loss in filter components. Therefore, the proposed PWM strategy results in significant efficiency improvement. Additionally, the AHCU PWM also compensates for the zero-crossing distortion problem of dual-buck full-bridge inverter. Several PWM techniques are analyzed and compared, including bipolar PWM, unipolar PWM and phase-shifted PWM, when applied to the proposed cascade dual-buck full-bridge inverter. It has been found out that a PWM combination technique with the use of two out of the three PWMs leads to better performance in terms of less output current ripple and harmonics, no zero-crossing distortion, and higher efficiency. A grid-tie control system is proposed for cascade dual-buck inverter with both active and reactive power flow capability in a wide range under two types of renewable energy and distributed generation sources. Fuel cell power conditioning system (PCS) is Type I system with active power command generated by balance of plant (BOP) of each unit; and photovoltaic or wind PCS is Type II system with active power harvested by each front-end unit through maximum power point tracking (MPPT). Reactive power command is generated by distributed generation (DG) control site for both systems. Selective harmonic proportional resonant (PR) controller and admittance compensation controller are first introduced to cascade inverter grid-tie control to achieve better steady-state and dynamic performances. / Ph. D.
60

Modeling and Control Design of a Bidirectional PWM Converter for Single-phase Energy Systems

Dong, Dong 02 September 2009 (has links)
This thesis proposes a complete modeling and control design methodology for a multifunctional single-phase bidirectional PWM converter in renewable energy systems. There is a generic current loop for different modes of operation to ease the transition between different modes, including stand-alone inverter mode, grid-tied inverter mode, grid-tied rectifier mode and grid-tied charger/discharger mode. Under stand-alone mode operation, ac voltage regulation is of importance because of the sensitive loads. In this thesis, different multi-loop-based control schemes are investigated and compared, especially between the load current feedback control, PR control and capacitor current loop control. It shows that PR controller reduces the steady-state error, while load current feedback controller improves the transient response. However, the load current feedback controller and capacitor current loop controller presents unstable outputs under some filter load condition. Single-phase d-q frame control is also studied. In order to ease the implementation effort, an unbalanced d-q frame control is proposed to achieve zero steady-state error voltage regulation without generating β-axis component. Based on the same principle, a d-q frame-based single-phase PLL is also proposed to achieve the fast dynamic response with the zero steady-state error phase tracking. The entire control system is verified on a modified 7 kW single-phase PWM converter prototype with a simple DSP-based digital implementation. The load step response test is presented under different modes of operation. The controllers for stand-alone mode are also done under no load, 1 kW resistive load, 1kVar capacitive load, and non-linear load conditions verifying that the single-phase d-q achieves 70% steady-state error improvement if taking the normal PID controller as the baseline design. In the end, the proposed PLL is compared with the standard PLL by experiments showing that the steady-state error can be reduced by 80%. / Master of Science

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