4 research outputs found
Desenvolvimento de padrões de verificação para medições de tensão e corrente aplicadas ao controle da operação de sistemas de transmissão de energia elétrica
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Metrologia Científica e Industrial.Os sistemas elétricos de geração, transmissão e distribuição de energia elétrica crescem continuamente, em porte e em complexidade. Em função disso, crescem também as exigências com relação à supervisão e ao controle das grandezas envolvidas. Esse papel é desempenhado pelos denominados sistemas de medição operacional. Apesar da importância desses sistemas, verifica-se que há dentro do setor elétrico uma grande diferença de rigorismo no tratamento metrológico quando comparado ao dispensado aos sistemas destinados à medição de faturamento. Enquanto para a medição operacional pouca atenção é dada aos aspectos metrológicos, a medição de faturamento é revestida de rigoroso formalismo, através de freqüentes processos de calibração e sucessivas auditorias de agentes externos. Verificações periódicas são procedimentos corriqueiros nos processos de garantia da confiabilidade metrológica em praticamente todas as áreas do conhecimento. Dificuldades operacionais e falta de normatização específica fazem com que tal não seja usual na medição operacional. Visando contribuir para aumentar a confiabilidade nas medições operacionais este trabalho estabelece requisitos, analisa alternativas e descreve o desenvolvimento e a avaliação experimental de padrões de verificação de tensão e de corrente. Os sistemas de medição desenvolvidos foram testados em campo e em laboratório de metrologia rastreado a padrões internacionais. Os resultados mostram grande potencial para aplicação como padrões de referência em verificações, nas medições operacionais. Conseguiu-se implementar instrumentos não invasivos, operacionalmente seguros, de custo relativamente baixo e de exatidão adequada
Micro-manufactured Rogowski coils for fault detection of aircraft electrical wiring and interconnect systems (EWIS)
Aircraft wiring failures have increased over the last few years resulting in arc faults and
high-energy flashover on the wiring bundle, which can propagate down through aircraft
Electrical Wiring and Interconnect Systems (EWIS). It is considered cost prohibitive to
completely rewire a plane in terms of man hours and operational time lost to do this,
and most faults are only detectable whilst the aircraft is in flight. Temperature, humidity
and vibration all accelerate ageing and failure effects on EWIS.
This research investigates methods of in-situ non-invasive testing of aircraft wiring
during fight. Failure Mode Effects and Analysis (FMEA) was performed on legacy
aircraft EWIS using data obtained from RAF Brize Norton. Micro-Electro-mechanical-
Systems (MEMS) were evaluated for use in a wire monitoring system that measures the
environmental parameters responsible for ageing and failure of EWIS. Such MEMS can
be developed into a Health and Usage Monitoring MicroSystem (HUMMS) by
incorporating advanced signal processing and prognostic software.
Current and humidity sensors were chosen for further investigation in this thesis. These
sensors can be positioned inside and outside cable connectors of EWIS so that arc faults
can be reliably detected and located. This thesis presents the design, manufacture and
test of micro-manufactured Rogowski sensors. The manufactured sensors were
benchmarked against commercial high frequency current transformers (HFCT), as these
devices can also detect high frequency current signature due to wire insulation failure.
Results indicate that these sensors possess superior voltage output compared to the
HFCT.
The design, manufacture and test of a polymer capacitive humidity sensor is also
presented. Two different types of polymer were reviewed as part of the evaluation. A
feature of the sensor design is recovery from exposure to chemicals found on wiring
bundles. Current and humidity sensors were demonstrated to be suitable for integrating
onto a common substrate with accelerometers, temperature sensors and pressure sensors
for health monitoring and prognostics of aircraft EWIS
Micro-manufactured Rogowski coils for fault detection of aircraft electrical wiring and interconnection systems (EWIS)
Aircraft wiring failures have increased over the last few years resulting in arc faults and
high-energy flashover on the wiring bundle, which can propagate down through aircraft
Electrical Wiring and Interconnect Systems (EWIS). It is considered cost prohibitive to
completely rewire a plane in terms of man hours and operational time lost to do this,
and most faults are only detectable whilst the aircraft is in flight. Temperature, humidity
and vibration all accelerate ageing and failure effects on EWIS.
This research investigates methods of in-situ non-invasive testing of aircraft wiring
during fight. Failure Mode Effects and Analysis (FMEA) was performed on legacy
aircraft EWIS using data obtained from RAF Brize Norton. Micro-Electro-mechanical-
Systems (MEMS) were evaluated for use in a wire monitoring system that measures the
environmental parameters responsible for ageing and failure of EWIS. Such MEMS can
be developed into a Health and Usage Monitoring MicroSystem (HUMMS) by
incorporating advanced signal processing and prognostic software.
Current and humidity sensors were chosen for further investigation in this thesis. These
sensors can be positioned inside and outside cable connectors of EWIS so that arc faults
can be reliably detected and located. This thesis presents the design, manufacture and
test of micro-manufactured Rogowski sensors. The manufactured sensors were
benchmarked against commercial high frequency current transformers (HFCT), as these
devices can also detect high frequency current signature due to wire insulation failure.
Results indicate that these sensors possess superior voltage output compared to the
HFCT.
The design, manufacture and test of a polymer capacitive humidity sensor is also
presented. Two different types of polymer were reviewed as part of the evaluation. A
feature of the sensor design is recovery from exposure to chemicals found on wiring
bundles. Current and humidity sensors were demonstrated to be suitable for integrating
onto a common substrate with accelerometers, temperature sensors and pressure sensors
for health monitoring and prognostics of aircraft EWIS.Engineering and Physical Sciences Research Council (EPSRC