terça-feira, 29 de junho de 2021
Estudo de controladores aplicados a inversores para UPS com operação ilhada-Hildo Guillardi Júnior-Dissertação (Mestrado)–Universidade Estadual Paulista. Faculdade de Engenharia, Bauru, 2013-BRASIL
Estudo de controladores aplicados a inversores para UPS com operação ilhada
Bauru-SP
2013
MESTRADO EM ENGENHARIA ELÉTRICA
unesp
Hildo Guillardi Júnior
RESUMO
Esta dissertação apresenta o projeto, simulação e ensaio dos protótipos da etapa de
saída de uma Fonte de Alimentação Ininterrupta (UPS – Uninterruptible Power Supply)
monofásica de tensão igual a 127V e trifásica com tensões 220/127V a 4 fios, ambas de
frequência 60Hz e potência nominal igual a 1kVA para uso em operação ilhada. A validação
da metodologia de projeto foi realizada primeiramente em simulação, e depois,
experimentalmente utilizando-se diferentes tipos de cargas tipicamente encontradas em
instalações elétricas e diferentes tipos de controladores clássicos: PI (Controlador
Proporcional Integral), Ressonante e composição dos dois. Os ensaios experimentais
consistiram em duas etapas, regime e transitório, na primeira sendo avaliado o
comportamento estático do conversor com parâmetros como valor eficaz (RMS – Root Mean
Square) e a Distorção Harmônica Total (THD – Total Harmonic Distortion) da tensão de
saída e, na segunda, o comportamento frente à entrada e saída de cargas, evidenciando a
estabilidade do controle. Nas duas etapas foram aplicados procedimentos normatizados de
ensaios e os resultados foram comparados com os requisitos das normas aplicáveis a esse tipo
de conversor. Como dispositivo de controle utilizou-se um Processador Digital de Sinais
(DSP – Digital Signal Processing) de ponto fixo, responsável pelo cálculo do algoritmo de
controle e leitura dos sinais de tensões e correntes do inversor; sendo avaliada sua capacidade
de processamento frente à manutenção da qualidade e da frequência do sinal de saída. O
projeto aponta a necessidade do controle multimalhas, ou seja, o controle da tensão mais
corrente, devido à instabilidade criada em sua função de transferência ao alimentar as cargas
não resistivas. Também é mostrada, em simulação, a possibilidade de trabalho da interface de
potência do protótipo em outros propósitos: Retificador com Alto Fator de Potência (para
recarga da bateria), Fonte de Corrente (para interconexão com a rede elétrica) e, utilizando a
Teoria da Potência Conservativa (CPT – Conservative Power Theory), operação como Filtro
Ativo Paralelo (compensador de distúrbios relacionados à corrente elétrica).
sábado, 19 de junho de 2021
위상 배열 무선 전력 전송 용 초고주파 마그네트론 주파수 및 위상 제어 Frequency and Phase Control of a Microwave Magnetron for Phased Array Wireless Power Transfer-Daejeon University of Science and Technology -2020
위상 배열 무선 전력 전송 용 초고주파 마그네트론 주파수 및 위상 제어 Frequency and Phase Control of a Microwave Magnetron for Phased Array Wireless Power Transfer
Author
Kim Do-kyun
Issues
Daejeon University of Science and Technology Graduate School, 2020
Degree thesis matters
Thesis (Master's)-- University of Science and Technology Graduate School : Energy and Power Conversion Engineering 2020.
Year of issue
2020
writing language Korean
ABSTRACT
Space solar power system (SSPS) requires to transfer
electrical energy from space to the Earth. For this purpose,
long-range wireless power transfer technology based on
microwave phased array has been studied. The unit device for
phased array system must have high energy conversion
efficiency per volume. Magnetron based on vacuum electronics
can be an optimal device that meets this requirement.
Magnetron has higher DC-RF conversion efficiency than solid
state devices have. But it suffers from frequency and phase
noise so that it has limitations to using it as a unit device for a
phased array system. In this paper, stabilization & control of 2.45
GHz Magnetron’s frequency and phase are reported. In order to
stabilize the Magnetron oscillation frequency, we designed a high
voltage filter for Magnetron power supply (SM445). Then we
applied injection locking technique to control Magnetron’s
frequency. A phase locking loop (PLL) is constructed for more
precise phase stabilization.
Phase stability of 0.3° is achieved by PLL based on injection
locking technique. We expect our accomplishment can contribute
to microwave-based phased array wireless power transfer.
sexta-feira, 18 de junho de 2021
태양전지의 모델링을 이용한 PCS 특성에 관한 연구 A Study on the Characteristics of PCS Using a Modeling of Solar Cells BY KIM SUNG-SOO Electrical & Electronic Major Semyung University Graduate School
태양전지의 모델링을 이용한 PCS 특성에 관한 연구
A Study on the Characteristics of PCS Using a
Modeling of Solar Cells
BY KIM SUNG-SOO
Electrical & Electronic Major
Semyung University Graduate School
ABSTRACT
In this paper, we modeled the devices used in PV system easily.
Simulation tools use PSPICE to enable intuitive electrical circuit
simulations. Simulations were also performed on the effects of
temperature and spatial radiation that are easy to overlook when using
solar cells using modelled libraries. In addition, for full operation of the
photovoltaic system, a complete operation system for the DC-DC
buck-boost converter and the MPPT(Maximum Power Point Tracking)
control system was modeled and simulated to confirm good operation.
In order to verify the operation of the simulation, we constructed an
actual system with the same conditions in the simulation and
experimented. As a result, we proposed a single-phase 3 kW
grid-connected solar power converter. In addition to IGBT devices and
GaN type MOSFETs We have obtained design data that can be
diversified and increased in capacity considering the capacity.
Especially, it is confirmed that GaN type MOSFET is the next
generation switching device. It is possible to expand the switching
frequency to 200 [kHz] and greatly reduce the size of the heat sink
which can greatly improve efficiency and power factor.
In future, it can be used as a stand-alone system with ESS using
solar inverter, and it is possible to regenerate energy to the battery
power side, and it has efficiency of 95% or more and energy saving
effect is confirmed.
quarta-feira, 9 de junho de 2021
Reduction of Total Harmonic Distortion (THD) on Multilevel Inverter with Modified PWM using Genetic Algorithm Lucky Pradigta S.R., Ony Asrarul Q., Zainal Arief, Novie Ayub Windarko Politeknik Elektronika Negeri Surabaya
Politeknik Elektronika Negeri Surabaya
International Journal of Engineering Technology
Abstract
In this research, modified PWM has been applied to the multilevel
inverter (MLI) single‐phase three‐level diode clamp full bridge.
Modified PWM is performed to produce minimum Total Harmonic
Distortion (THD) the voltage because the quality of the good voltage
is indicated by small THD. The THD indicates the quality of AC
voltage source. The THD standard by the IEEE STD 519‐1992
Harmonic Voltage Limits is 5% and the Pacific Corp standard is 8%, if
the THD value is greater than the THD standard it can cause the
electronic load to be damaged due to the damaged waveform.
Modified PWM is applied by adding a 50 Hz sinusoidal reference
signal with a sinusoidal signal which has a certain amplitude,
frequency and phase shift angle. The frequency of the adder signal is
the frequency at which the value of the individual harmonic voltage
appears (n harmonic). To get maximum result, optimization using
Genetic Algorithm (GA) method to determinate amplitude & phase
shift angle done. The result of implementation hardware with
modified PWM shows smaller THD voltage compared to the THD
voltage with Sinusoidal Pulse Width Modulation (SPWM) switching
up to 0.19 or decrease 65,51 % for modified PWM of harmonic
injection n = 7 with GA optimization ma= 0.8 (A=0.0936 and ø = 0
rad) and up to 0.08 or decrease 12,30 % for modified PWM of
harmonic injection n = 22 with GA optimization ma = 0.4 (A=0.1221
and ø = 0 rad).
Keywords: Multilevel Inverter, Modified PWM, Genetic Algorithm.
quarta-feira, 2 de junho de 2021
Ruggedness of High-Voltage IGBTs and Protection Solutions by Thomas Basler Approved to obtain the degree of Doctor of Engineer. Technical University of Chemnitz
Ruggedness of High-Voltage IGBTs and
Protection Solutions
by Thomas Basler
Approved to obtain the degree of Doctor of Engineer.
Technical University of Chemnitz
Bibliographic information from the German National Library
The German National Library lists this publication in the
German National
Bibliography; detailed bibliographical information is in the
Available on the Internet at http://dnb.d-nb.de.
This work was supported by the Faculty of Electrical Engineering and
Information technology from the Technical University of Chemnitz as a dissertation
Approved to obtain the degree of Doctor of Engineer.
The work was written in English.
Date of submission: September 10, 2013
Reviewer: Prof. Dr. Josef Lutz
Prof. Dr. Steffen Bernet
Dr. Roland Jakob
Defense Day: February 28, 2014
ABSTRACT
Application-Oriented IGBT Requirements and
Motivation of this Work This thesis was written at Chemnitz University of Technology in cooperation
with General Electric Energy Power Conversion GmbH, former Converteam,
in Berlin. Many of the tasks and problem-settings regarding the improvement
of ruggedness of high-voltage IGBTs were derived directly from the industry
partner and its 3-level medium-voltage converter application. This topology
is widely used for industrial and traction applications [Ber00]. For the considered
converter, 42-chip press-pack IGBTs with a voltage rating of 4.5 kV
are used. The challenge was to investigate all possible IGBT short-circuit
cases in this type of converter and to shift the complete converter protection
concept to the optimum level. The interconnection between the gate unit and
the IGBT and the surrounding circuit parameters like the stray and shortcircuit
inductance were of special interest. In addition to the short-circuit
topic, a solution should be found on how to protect the load of the converter
(e.g. a large windmill generator) against asymmetric short-circuit currents
and alternating torques, see Chapter 5. For this purpose, the surge-current
mode of the IGBT is introduced and verified. It will be shown that this special
mode can be handled by the IGBT without destruction or significant
ageing.
To meet the requirements and test conditions mentioned above, a singlechip
test bench was constructed. New phenomena like the self-turn-off mechanism
or special IGBT destructions under short-circuit and surge-current
mode were studied in detail. Countermeasures were found to protect the
IGBT and the complete power-electronic circuit and application from a possible
destruction.
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