This paper offers a systematic literature review of real-time detection and classification of Power Quality Disturbances(PQDs).A particular focus is given to voltage sags and notches,as voltage sags cause huge economi...This paper offers a systematic literature review of real-time detection and classification of Power Quality Disturbances(PQDs).A particular focus is given to voltage sags and notches,as voltage sags cause huge economic losses while research on voltage notches is still very incipient.A systematic method based on scientometrics,text similarity and the analytic hierarchy process is proposed to structure the review and select the most relevant literature.A biblio-metric analysis is then performed on the bibliographic data of the literature to identify relevant statistics such as the evolution of publications over time,top publishing countries,and the distribution by relevant topics.A set of articles is subsequently selected to be critically analyzed.The critical review is structured in steps for real-time detection and classification of PQDs,namely,input data preparation,preprocessing,transformation,feature extraction,feature selec-tion,detection,classification,and characterization.Aspects associated with the type of disturbance(s)addressed in the literature are also explored throughout the review,including the perspectives of those studies aimed at multiple PQDs,or specifically focused on voltage sags or voltage notches.The real-time performance of the reviewed tools is also examined.Finally,unsolved issues are discussed,and prospects are highlighted.展开更多
Fish mortality assessments for turbine passages are currently performed by live-animal testing with up to a hundred thousand fish per year in Germany.A propelled sensor device could act as a fish surrogate.In this con...Fish mortality assessments for turbine passages are currently performed by live-animal testing with up to a hundred thousand fish per year in Germany.A propelled sensor device could act as a fish surrogate.In this context,the study presented here investigates the state of the art via a thorough literature review on propulsion systems for aquatic robots.An evaluation of propulsion performance,weight,size and complexity of the motion achievable allows for the selection of an optimal concept for such a fish mimicking device carrying the sensors.In the second step,the design of a bioinspired soft robotic fish driven by an unconventional drive system is described.It is based on piezoceramic actuators,which allow for motion with five degrees of freedom(DOF)and the creation of complex bio-mimicking body motions.A kinematic model for the motion’s characteristics is developed,to achieve accurate position feedback with the use of strain gauges.Optical measurements validate the complex deformation of the body and deliver the basis for the calibration of the kinematic model.Finally,it can be shown,that the calibrated model presented allows the tracking of the deformation of the entire body with an accuracy of 0.1 mm.展开更多
文摘This paper offers a systematic literature review of real-time detection and classification of Power Quality Disturbances(PQDs).A particular focus is given to voltage sags and notches,as voltage sags cause huge economic losses while research on voltage notches is still very incipient.A systematic method based on scientometrics,text similarity and the analytic hierarchy process is proposed to structure the review and select the most relevant literature.A biblio-metric analysis is then performed on the bibliographic data of the literature to identify relevant statistics such as the evolution of publications over time,top publishing countries,and the distribution by relevant topics.A set of articles is subsequently selected to be critically analyzed.The critical review is structured in steps for real-time detection and classification of PQDs,namely,input data preparation,preprocessing,transformation,feature extraction,feature selec-tion,detection,classification,and characterization.Aspects associated with the type of disturbance(s)addressed in the literature are also explored throughout the review,including the perspectives of those studies aimed at multiple PQDs,or specifically focused on voltage sags or voltage notches.The real-time performance of the reviewed tools is also examined.Finally,unsolved issues are discussed,and prospects are highlighted.
基金Open Access funding enabled and organized by Projekt DEALpart of the RETERO project(https://retero.org).S.A.was funded by the German Ministry of Education and Research(BMBF)with grant number 031L0152A.
文摘Fish mortality assessments for turbine passages are currently performed by live-animal testing with up to a hundred thousand fish per year in Germany.A propelled sensor device could act as a fish surrogate.In this context,the study presented here investigates the state of the art via a thorough literature review on propulsion systems for aquatic robots.An evaluation of propulsion performance,weight,size and complexity of the motion achievable allows for the selection of an optimal concept for such a fish mimicking device carrying the sensors.In the second step,the design of a bioinspired soft robotic fish driven by an unconventional drive system is described.It is based on piezoceramic actuators,which allow for motion with five degrees of freedom(DOF)and the creation of complex bio-mimicking body motions.A kinematic model for the motion’s characteristics is developed,to achieve accurate position feedback with the use of strain gauges.Optical measurements validate the complex deformation of the body and deliver the basis for the calibration of the kinematic model.Finally,it can be shown,that the calibrated model presented allows the tracking of the deformation of the entire body with an accuracy of 0.1 mm.
