Power cables are integral to modern urban power transmission and distribution systems.For power cable asset managers worldwide,a major challenge is how to manage effectively the expensive and vast network of cables,ma...Power cables are integral to modern urban power transmission and distribution systems.For power cable asset managers worldwide,a major challenge is how to manage effectively the expensive and vast network of cables,many of which are approaching,or have past,their design life.This study provides an in-depth review of recent research and development in cable failure analysis,condition monitoring and diagnosis,life assessment methods,fault location,and optimisation of maintenance and replacement strategies.These topics are essential to cable life cycle management(LCM),which aims to maximise the operational value of cable assets and is now being implemented in many power utility companies.The review expands on material presented at the 2015 JiCable conference and incorporates other recent publications.The review concludes that the full potential of cable condition monitoring,condition and life assessment has not fully realised.It is proposed that a combination of physics-based life modelling and statistical approaches,giving consideration to practical condition monitoring results and insulation response to in-service stress factors and short term stresses,such as water ingress,mechanical damage and imperfections left from manufacturing and installation processes,will be key to success in improved LCM of the vast amount of cable assets around the world.展开更多
On-line partial discharge(PD)monitoring is being increasingly adopted to improve the asset management and maintenance of medium-voltage(MV)motors.This study presents a novel method for autonomous analysis and classifi...On-line partial discharge(PD)monitoring is being increasingly adopted to improve the asset management and maintenance of medium-voltage(MV)motors.This study presents a novel method for autonomous analysis and classification of motor PD patterns in situations where a phase-reference voltage waveform is not available.The main contributions include a polar PD(PPD)pattern and a fractal theory-based autonomous PD recognition method.PPD pattern that is applied to convert the traditional phase-resolved PD pattern into a circular form addresses the lack of phase information in on-line PD monitoring system.The fractal theory is then presented in detail to address the task of discrimination of 6 kinds of single source and 15 kinds of multi-source PD patterns related to motors,as outlined in IEC 60034.The classification of known and unknown defects is calculated by a method known as centre score.Validation of the proposed method is demonstrated using data from laboratory experiments on three typical PD geometries.This study also discusses the application of the proposed techniques with 24 sets of on-site PD measurement data from 4 motors in 2 nuclear power stations.The results show that the proposed method performs effectively in recognising not only the single-source PD but also multi-source PDs.展开更多
文摘Power cables are integral to modern urban power transmission and distribution systems.For power cable asset managers worldwide,a major challenge is how to manage effectively the expensive and vast network of cables,many of which are approaching,or have past,their design life.This study provides an in-depth review of recent research and development in cable failure analysis,condition monitoring and diagnosis,life assessment methods,fault location,and optimisation of maintenance and replacement strategies.These topics are essential to cable life cycle management(LCM),which aims to maximise the operational value of cable assets and is now being implemented in many power utility companies.The review expands on material presented at the 2015 JiCable conference and incorporates other recent publications.The review concludes that the full potential of cable condition monitoring,condition and life assessment has not fully realised.It is proposed that a combination of physics-based life modelling and statistical approaches,giving consideration to practical condition monitoring results and insulation response to in-service stress factors and short term stresses,such as water ingress,mechanical damage and imperfections left from manufacturing and installation processes,will be key to success in improved LCM of the vast amount of cable assets around the world.
文摘On-line partial discharge(PD)monitoring is being increasingly adopted to improve the asset management and maintenance of medium-voltage(MV)motors.This study presents a novel method for autonomous analysis and classification of motor PD patterns in situations where a phase-reference voltage waveform is not available.The main contributions include a polar PD(PPD)pattern and a fractal theory-based autonomous PD recognition method.PPD pattern that is applied to convert the traditional phase-resolved PD pattern into a circular form addresses the lack of phase information in on-line PD monitoring system.The fractal theory is then presented in detail to address the task of discrimination of 6 kinds of single source and 15 kinds of multi-source PD patterns related to motors,as outlined in IEC 60034.The classification of known and unknown defects is calculated by a method known as centre score.Validation of the proposed method is demonstrated using data from laboratory experiments on three typical PD geometries.This study also discusses the application of the proposed techniques with 24 sets of on-site PD measurement data from 4 motors in 2 nuclear power stations.The results show that the proposed method performs effectively in recognising not only the single-source PD but also multi-source PDs.
