| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 3.97 MB | Adobe PDF |
Authors
Abstract(s)
As primeiras referências a máquinas multifásicas remontam aos anos 60 do século
XX [1]. No entanto, só no inico do século XXI, por força da grande melhoria e eficiência dos
conversores eletrónicos de potência, é que este tipo de máquinas despertou o interesse da
comunidade científica.
As máquinas multifásicas caracterizam-se por possuírem um número de fases
superior a 3 e apresentam como principais vantagens, relativamente às suas congéneres
trifásicas, menor pulsação de binário, maior densidade de potência e maior tolerância a
falhas [2]. Em contrapartida, excetuando a máquina hexafásica com enrolamento simétrico,
a alimentação das máquinas polifásicas tem de ser efetuada por intermédio de um conversor
eletrónico de potência que permita criar um sistema polifásico, adequado ao tipo de
enrolamento da máquina, a partir da rede de alimentação.
A crescente procura por acionamentos elétricos de velocidade varável capazes de
cumprirem com critérios cada vez mais exigentes de eficiência energética e apresentando
níveis elevados de fiabilidade e disponibilidade tornou evidente a necessidade de se analisar
os modos de falha, e seus efeitos, de desenvolver métodos capazes de detetar avarias de
caracter evolutivo num estado inicial e de estratégias de controlo que permitam operar o
acionamento em caso de avaria, ainda que com algumas limitações no seu desempenho.
Neste trabalho, apresenta-se uma abordagem teórica às máquinas de indução com
seis fases, suas características construtivas, princípio de funcionamento, aplicações e tipos
de falhas predominantes. Posteriormente, será apresentado um modelo computacional da
máquina, desenvolvido para a análise do desempenho da máquina em funcionamento
normal (saudável) e na presença de avarias no estator (curto-circuito entre espiras).
Apresenta-se, ainda, a validação do modelo computacional desenvolvido. Por fim,
apresentar-se-á uma metodologia adequada ao diagnóstico de avarias no estator, mais
precisamente de curto-circuitos entre espiras.
The first references to polyphase machines date back to the 60’s of the 20th century [1]. However, it was only at the beginning of the 21st century that this type of machines stimulated the interest of the scientific community, due to the great improvement and efficiency of electronic power converters. Multiphase machines are characterized by having a number of phases greater than 3 and have as main advantages, in relation to their three-phase counterparts, lower torque pulsation, higher power density and greater fault tolerance [2]. On the other hand, except for the six-phase machine with symmetrical winding, the supply of the multiphase machines must be carried out by means of an electronic power converter that allows the creation of a multiphase system, suitable for the type of winding of the machine, from the grid supply. The growing demand for variable speed electric drives capable of satisfy increasingly demanding criteria of energy efficiency and presenting high levels of reliability and availability made evident the necessity to analyze the failure modes, and their effects, to develop methods capable of detect evolutionary failures in an initial state and control strategies that allow the drive to be operated in the event of a failure, although with some limitations in its performance. In this work, a theoretical approach of induction machines with six phases is presented, with their constructive characteristics, operating principle, applications and predominant types of failures. Later, a computational model of the machine will be presented, developed for the analysis of the machine's performance in normal operation (healthy) and in the presence of faults in the stator (inter-turn short circuit). The validation of the developed computational model is also presented. Finally, an adequate methodology will be presented for the diagnosis of faults in the stator, more precisely for inter-turn shortcircuits.
The first references to polyphase machines date back to the 60’s of the 20th century [1]. However, it was only at the beginning of the 21st century that this type of machines stimulated the interest of the scientific community, due to the great improvement and efficiency of electronic power converters. Multiphase machines are characterized by having a number of phases greater than 3 and have as main advantages, in relation to their three-phase counterparts, lower torque pulsation, higher power density and greater fault tolerance [2]. On the other hand, except for the six-phase machine with symmetrical winding, the supply of the multiphase machines must be carried out by means of an electronic power converter that allows the creation of a multiphase system, suitable for the type of winding of the machine, from the grid supply. The growing demand for variable speed electric drives capable of satisfy increasingly demanding criteria of energy efficiency and presenting high levels of reliability and availability made evident the necessity to analyze the failure modes, and their effects, to develop methods capable of detect evolutionary failures in an initial state and control strategies that allow the drive to be operated in the event of a failure, although with some limitations in its performance. In this work, a theoretical approach of induction machines with six phases is presented, with their constructive characteristics, operating principle, applications and predominant types of failures. Later, a computational model of the machine will be presented, developed for the analysis of the machine's performance in normal operation (healthy) and in the presence of faults in the stator (inter-turn short circuit). The validation of the developed computational model is also presented. Finally, an adequate methodology will be presented for the diagnosis of faults in the stator, more precisely for inter-turn shortcircuits.
Description
Keywords
Análise e Diagnóstico de Avarias Estatóricas
Em Motores de Indução Hexafásicos Com Enrolamento Simétrico