Pub Date : 2018-06-01DOI: 10.1109/EIC.2018.8481094
Andrea L. Caprara, A. Cavallini, Luca Garagnani, J. Guo
Electrical distribution grids consist of many Medium Voltage (MV) devices, each one of them being a possible cause of fault. The demand for their increasing reliability and decreasing maintenance/replacement costs, together with the high number of installed apparatuses, is turning the focus of the condition assessment to smart solutions, integrable in networks, able to evaluate autonomously the condition of the electrical asset and, in case of anomalies, to request for man-operated support. In this paper, a novel approach to the continuous monitoring of PD phenomena in MV grids will be described. The devised solution addresses the requirements of the MV grids in that the system is non-invasive and low cost. PD data acquisition and processing systems are fully automatic, with the relevant assessment of the conditions of the MV piece of equipment. A comprehensive description of the proposed technological solution is reported, focusing mainly on the automatic acquisition and processing of PD data, automatic noise rejection and the recognition of increasing PD trend as a tool to trigger warning signals. To show the effectiveness of the proposed approach, case studies will be reported for various MV pieces of equipment, particularly on Switchgears and Ring Main Units.
{"title":"A Novel Approach for Continuous Monitoring of Partial Discharge Phenomena on Medium Voltage Equipments","authors":"Andrea L. Caprara, A. Cavallini, Luca Garagnani, J. Guo","doi":"10.1109/EIC.2018.8481094","DOIUrl":"https://doi.org/10.1109/EIC.2018.8481094","url":null,"abstract":"Electrical distribution grids consist of many Medium Voltage (MV) devices, each one of them being a possible cause of fault. The demand for their increasing reliability and decreasing maintenance/replacement costs, together with the high number of installed apparatuses, is turning the focus of the condition assessment to smart solutions, integrable in networks, able to evaluate autonomously the condition of the electrical asset and, in case of anomalies, to request for man-operated support. In this paper, a novel approach to the continuous monitoring of PD phenomena in MV grids will be described. The devised solution addresses the requirements of the MV grids in that the system is non-invasive and low cost. PD data acquisition and processing systems are fully automatic, with the relevant assessment of the conditions of the MV piece of equipment. A comprehensive description of the proposed technological solution is reported, focusing mainly on the automatic acquisition and processing of PD data, automatic noise rejection and the recognition of increasing PD trend as a tool to trigger warning signals. To show the effectiveness of the proposed approach, case studies will be reported for various MV pieces of equipment, particularly on Switchgears and Ring Main Units.","PeriodicalId":184139,"journal":{"name":"2018 IEEE Electrical Insulation Conference (EIC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130129657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.1109/EIC.2018.8481070
Martin Scheler, M. Rossner, Lukas Reißenweber, F. Berger, U. Prucker, Andreas Hopf
In the field of HVDC bushings, temperature gradients inside the bushing core have more impact on the electric field distribution compared to AC. Furthermore, more experiences are existing in the DC case for the oil-insulation system than for solid-gas. The aim is to study the potential distribution in the bushing core of a solid-gas insulated high voltage bushing at very low frequencies (5 mHz to 100 mHz) under the effect of a temperature gradient. Previous investigations suggest that, after a DC voltage is applied, it takes dozens of hours before a true DC field condition is reached due to the end of all polarization processes in the insulation material. An investigation at very low frequencies is therefore reasonable to determine the temperature behavior of the capacitive-resistive transition. As test object, a single-sided 180 kV bushing core is used (only one end of the core is graded). Five metal foils of the capacitive grading were carried out of the ungraded side of the core, so potential measurements on this foils could be undertaken, and furthermore, the distortion of the electric field by the metal foils is lower compared to a double-sided grading. The test arrangement also allows measurements under different insulation gases with different pressures. Air is used as insulation gas since the test voltages are lower than or equal 30 kV. AC measurements are performed via capacitive sensor. In case of DC, the sensor evaluates the initial magnitude of the discharging process of a charged capacity. The distortion of the field distribution within the bushing core, caused by the influence of the measuring device has no significant impact, because its additional capacitive load is less than 80 pF. Since it is of deterministic nature, its influence can be taken into account. To perform a temperature gradient, the primary conductor is heated until the temperature gradient reached a constant value, and then set under voltage. At the one hand, the temperature and voltage distribution in the bushing core is measured, and on the other hand it is verified with our investigations of the material properties.
{"title":"Potential Distribution in the Bushing Core of a Solid-Gas Insulated High Voltage Bushing in the Very Low Frequency Region Under the Effect of a Temperature Gradient","authors":"Martin Scheler, M. Rossner, Lukas Reißenweber, F. Berger, U. Prucker, Andreas Hopf","doi":"10.1109/EIC.2018.8481070","DOIUrl":"https://doi.org/10.1109/EIC.2018.8481070","url":null,"abstract":"In the field of HVDC bushings, temperature gradients inside the bushing core have more impact on the electric field distribution compared to AC. Furthermore, more experiences are existing in the DC case for the oil-insulation system than for solid-gas. The aim is to study the potential distribution in the bushing core of a solid-gas insulated high voltage bushing at very low frequencies (5 mHz to 100 mHz) under the effect of a temperature gradient. Previous investigations suggest that, after a DC voltage is applied, it takes dozens of hours before a true DC field condition is reached due to the end of all polarization processes in the insulation material. An investigation at very low frequencies is therefore reasonable to determine the temperature behavior of the capacitive-resistive transition. As test object, a single-sided 180 kV bushing core is used (only one end of the core is graded). Five metal foils of the capacitive grading were carried out of the ungraded side of the core, so potential measurements on this foils could be undertaken, and furthermore, the distortion of the electric field by the metal foils is lower compared to a double-sided grading. The test arrangement also allows measurements under different insulation gases with different pressures. Air is used as insulation gas since the test voltages are lower than or equal 30 kV. AC measurements are performed via capacitive sensor. In case of DC, the sensor evaluates the initial magnitude of the discharging process of a charged capacity. The distortion of the field distribution within the bushing core, caused by the influence of the measuring device has no significant impact, because its additional capacitive load is less than 80 pF. Since it is of deterministic nature, its influence can be taken into account. To perform a temperature gradient, the primary conductor is heated until the temperature gradient reached a constant value, and then set under voltage. At the one hand, the temperature and voltage distribution in the bushing core is measured, and on the other hand it is verified with our investigations of the material properties.","PeriodicalId":184139,"journal":{"name":"2018 IEEE Electrical Insulation Conference (EIC)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128248884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.1109/EIC.2018.8481106
M. Kawada
Condition monitoring techniques for ground coils used in superconducting magnetic levitation (Maglev) systems are required. In this study, an on-board radio interferometer system with a vector-antenna was developed to locate partial discharge (PD) sources occurring in propulsion coils of superconducting Maglev systems and to know the propagation characteristics of electromagnetic (EM) waves emitted from PD sources. PD current generally develops into multiple directions, that is, the EM waves emitted from the PD current have also multidirectional components. The structures and the arrangement of propulsion coils and levitation-guidance coils might influence the propagation of EM waves. The vector-antenna composed of vertical and horizontal dipole-antennas was set to the center of the antenna-array of the on-board radio interferometer system. Three sets of mock-ups of the propulsion coil and the levitation-guidance coil were also developed in order to evaluate easily the on-board radio interferometer system. One of the propulsion coils has eight cylinder-shaped holes penetrating through the insulating material to the inner conductor for attaching a cap with a needle-electrode; one or some of the holes can be voluntarily chosen. PD current was generated in an air-gap between the tip of the needle-electrode and the surface of the inner conductor. Experimental results show that a PD source generated at a voluntary position of the propulsion coil could be located by using the on-board radio interferometer system; the vertical and horizontal components (electric fields) of the EM waves emitted from the PD source could be separately received by using the vector-antenna.
{"title":"Detection of Partial Discharges Occurring in Propulsion Coils of Superconducting Maglev Systems Using an On-Board Radio Interferometer System with a Vector-Antenna","authors":"M. Kawada","doi":"10.1109/EIC.2018.8481106","DOIUrl":"https://doi.org/10.1109/EIC.2018.8481106","url":null,"abstract":"Condition monitoring techniques for ground coils used in superconducting magnetic levitation (Maglev) systems are required. In this study, an on-board radio interferometer system with a vector-antenna was developed to locate partial discharge (PD) sources occurring in propulsion coils of superconducting Maglev systems and to know the propagation characteristics of electromagnetic (EM) waves emitted from PD sources. PD current generally develops into multiple directions, that is, the EM waves emitted from the PD current have also multidirectional components. The structures and the arrangement of propulsion coils and levitation-guidance coils might influence the propagation of EM waves. The vector-antenna composed of vertical and horizontal dipole-antennas was set to the center of the antenna-array of the on-board radio interferometer system. Three sets of mock-ups of the propulsion coil and the levitation-guidance coil were also developed in order to evaluate easily the on-board radio interferometer system. One of the propulsion coils has eight cylinder-shaped holes penetrating through the insulating material to the inner conductor for attaching a cap with a needle-electrode; one or some of the holes can be voluntarily chosen. PD current was generated in an air-gap between the tip of the needle-electrode and the surface of the inner conductor. Experimental results show that a PD source generated at a voluntary position of the propulsion coil could be located by using the on-board radio interferometer system; the vertical and horizontal components (electric fields) of the EM waves emitted from the PD source could be separately received by using the vector-antenna.","PeriodicalId":184139,"journal":{"name":"2018 IEEE Electrical Insulation Conference (EIC)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132672392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.1109/EIC.2018.8481125
G. Montanari, P. Seri, Martin Stöck, Bayu Putra Andrianto, S. A. Filliben
This paper shows results of a preliminary study about electric strength and electrical endurance properties of various types of polyimide tapes, including the corona-resistant ones, in the presence and absence of partial discharges. Feasibility of insulation design for applications, such as automotive, where the rated voltage is increasing significantly, and the presence of partial discharges during operating life is likely, in investigated, with apparently positive indications.
{"title":"Investigating Electrical Performance of Polyimide Insulation Tapes for Automotive Application","authors":"G. Montanari, P. Seri, Martin Stöck, Bayu Putra Andrianto, S. A. Filliben","doi":"10.1109/EIC.2018.8481125","DOIUrl":"https://doi.org/10.1109/EIC.2018.8481125","url":null,"abstract":"This paper shows results of a preliminary study about electric strength and electrical endurance properties of various types of polyimide tapes, including the corona-resistant ones, in the presence and absence of partial discharges. Feasibility of insulation design for applications, such as automotive, where the rated voltage is increasing significantly, and the presence of partial discharges during operating life is likely, in investigated, with apparently positive indications.","PeriodicalId":184139,"journal":{"name":"2018 IEEE Electrical Insulation Conference (EIC)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122487106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.1109/EIC.2018.8481129
Alireza Naeini, E. Cherney, S. Jayaram
Evaluating the performance of the stress grading system by simulating the electric field and potential distributions in the overhang region shows that high conductive stress grading tape (SGT) reduces the maximum electric field at this region. For simulation studies, an accurate conductivity that takes into account the effects of vacuum pressure impregnation (VPI) process, temperature, and tape builds is measured. As the electric field on the SGT is enhanced under operating conditions, the conductivity of the SGT has been measured in a high electrical field condition under pulse conditions to minimize the effects of temperature rise on the SGT. The conductivity of a one half-lap layer and a double half-lap layer of SGT at different temperatures is measured. The results show that for both designs, the higher the tape conductivity the lower the maximum electric field in the SGT region. For evaluating the simulation model, the temperature profile along the stress grading system is measured and simulated under high frequency sinusoidal voltage.
{"title":"Effect of Stress Grading Tape Conductivity on the Electric Field Distribution in Stress Grading System of an Inverter-Fed Rotating Machine","authors":"Alireza Naeini, E. Cherney, S. Jayaram","doi":"10.1109/EIC.2018.8481129","DOIUrl":"https://doi.org/10.1109/EIC.2018.8481129","url":null,"abstract":"Evaluating the performance of the stress grading system by simulating the electric field and potential distributions in the overhang region shows that high conductive stress grading tape (SGT) reduces the maximum electric field at this region. For simulation studies, an accurate conductivity that takes into account the effects of vacuum pressure impregnation (VPI) process, temperature, and tape builds is measured. As the electric field on the SGT is enhanced under operating conditions, the conductivity of the SGT has been measured in a high electrical field condition under pulse conditions to minimize the effects of temperature rise on the SGT. The conductivity of a one half-lap layer and a double half-lap layer of SGT at different temperatures is measured. The results show that for both designs, the higher the tape conductivity the lower the maximum electric field in the SGT region. For evaluating the simulation model, the temperature profile along the stress grading system is measured and simulated under high frequency sinusoidal voltage.","PeriodicalId":184139,"journal":{"name":"2018 IEEE Electrical Insulation Conference (EIC)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125469209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.1109/EIC.2018.8481140
Tianxin Zhuang, M. Ren, Shujing Yang, M. Dong
Measurements of partial discharge play an important part in the study of dielectric materials, nevertheless, the physical processes of partial discharge are not yet clear. Pulse current method is recognized as the only effective way to quantify the charge. However, there is a limitation of such approach to detect PD pulses below the noise threshold and slow charge movement. In this work, a new technology “Excess Current Method” enables the measurement of the micro discharge and slow charge movements during PD. Proposed in some published studies, the excess current is referenced as the additional current component associated with the PD process by measuring the difference of dielectric response currents through a test object without and with PD activity. A measurement setup for simultaneous measurement of PD excess currents and PD currents averaged from about 300 periods is applied and three typical insulation defect models were tested under 50Hz voltage. Results of the excess currents during and after PD activity, including waveforms and charges are showed and discussed. The results indicate that the amplitude is higher and the charges are more of the excess currents than the PD currents, which reveals that some current components are ignored by pulsed current method but detected by excess current method. Furthermore, a weak excess current is measured for the dielectric barrier and air void PD models when the voltage dropped below the Partial Discharge Extinction Voltage (PDEV). The analysis of non-PD excess current also reflects the slow charge movements during PD. The measurement of excess current provides additional insight into PD mechanisms and shows the potential of completing the conventional PD detection.
{"title":"Excess Current Characteristics of Typical Insulation Defects Partial Discharge Under 50Hz","authors":"Tianxin Zhuang, M. Ren, Shujing Yang, M. Dong","doi":"10.1109/EIC.2018.8481140","DOIUrl":"https://doi.org/10.1109/EIC.2018.8481140","url":null,"abstract":"Measurements of partial discharge play an important part in the study of dielectric materials, nevertheless, the physical processes of partial discharge are not yet clear. Pulse current method is recognized as the only effective way to quantify the charge. However, there is a limitation of such approach to detect PD pulses below the noise threshold and slow charge movement. In this work, a new technology “Excess Current Method” enables the measurement of the micro discharge and slow charge movements during PD. Proposed in some published studies, the excess current is referenced as the additional current component associated with the PD process by measuring the difference of dielectric response currents through a test object without and with PD activity. A measurement setup for simultaneous measurement of PD excess currents and PD currents averaged from about 300 periods is applied and three typical insulation defect models were tested under 50Hz voltage. Results of the excess currents during and after PD activity, including waveforms and charges are showed and discussed. The results indicate that the amplitude is higher and the charges are more of the excess currents than the PD currents, which reveals that some current components are ignored by pulsed current method but detected by excess current method. Furthermore, a weak excess current is measured for the dielectric barrier and air void PD models when the voltage dropped below the Partial Discharge Extinction Voltage (PDEV). The analysis of non-PD excess current also reflects the slow charge movements during PD. The measurement of excess current provides additional insight into PD mechanisms and shows the potential of completing the conventional PD detection.","PeriodicalId":184139,"journal":{"name":"2018 IEEE Electrical Insulation Conference (EIC)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124357915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.1109/EIC.2018.8481056
Xuewei Zhang
Smart materials systems have been widely used to develop sensors, actuators and energy harvesters. This work is driven by the question about the possibility of strengthening electrical insulation systems via new designs based on smart materials/structures. Specifically, in this work, we seek for innovative solutions to partial discharge (PD) detection and mitigation inside gas or liquid insulated high voltage equipment by exploiting smart material systems' response to electric potential or current changes. The early-concept design includes a dielectric elastomer based actuator which has a spring that is relaxed when normal high voltage is applied to the elastomer (stretched). When partial discharge occurs, the voltage drop will cause the elastomer to contract, compress the spring, enlarge the insulation gap, and lower the electric field. The transient response of the dielectric elastomer actuator subject to PD voltage pulses is simulated. The results indicate that the systems can respond to PD in the direction toward PD suppression. This work also explores various settings to reveal the requirements on the material and system parameters for their use in high voltage insulation. This work presents a promising paradigm in the electrical insulation of high voltage equipment which combines sensing and actuating in the same material and features “responsive monitoring” by harnessing the electromechanical and/or electrochemical properties of smart materials.
{"title":"Design and Modeling of Smart Material Systems for High Voltage Insulation","authors":"Xuewei Zhang","doi":"10.1109/EIC.2018.8481056","DOIUrl":"https://doi.org/10.1109/EIC.2018.8481056","url":null,"abstract":"Smart materials systems have been widely used to develop sensors, actuators and energy harvesters. This work is driven by the question about the possibility of strengthening electrical insulation systems via new designs based on smart materials/structures. Specifically, in this work, we seek for innovative solutions to partial discharge (PD) detection and mitigation inside gas or liquid insulated high voltage equipment by exploiting smart material systems' response to electric potential or current changes. The early-concept design includes a dielectric elastomer based actuator which has a spring that is relaxed when normal high voltage is applied to the elastomer (stretched). When partial discharge occurs, the voltage drop will cause the elastomer to contract, compress the spring, enlarge the insulation gap, and lower the electric field. The transient response of the dielectric elastomer actuator subject to PD voltage pulses is simulated. The results indicate that the systems can respond to PD in the direction toward PD suppression. This work also explores various settings to reveal the requirements on the material and system parameters for their use in high voltage insulation. This work presents a promising paradigm in the electrical insulation of high voltage equipment which combines sensing and actuating in the same material and features “responsive monitoring” by harnessing the electromechanical and/or electrochemical properties of smart materials.","PeriodicalId":184139,"journal":{"name":"2018 IEEE Electrical Insulation Conference (EIC)","volume":"83 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120856122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.1109/EIC.2018.8481130
Simeng Li, Qingquan Li, W. Si, Junyan Yao, Yalin Shi, T. Zhang
The PD characteristics of oil-pressboard insulation with needle-plate defect at AC-DC combined voltage are unstable. In this paper, the time-variation trends of PD characteristics in pre-breakdown process at AC-DC combined voltage are studied via the tests in oil-pressboard insulation with needle-plate defect. The average PD repetition rate and average PD amplitude decrease with the PD developing, and the time-variation trends of them can be divided into fluctuation type and monotone type. The average PD amplitude has no obvious polarity effect, the average PD repetition rate has a polarity effect. In equivalent time-frequency spectrograms, most points move towards arch top with the developing of pre-breakdown processes, where PD equivalent time is 1300–1600 ns and PD equivalent frequency is 7.5-10 MHz. PD equivalent time-frequency spectrograms can be divided into half-arched type and whole-arched type at the end of pre-breakdown processes. The defect in pressboard caused by PD is a possible reason for the appearance of whole-arched time-frequency spectrogram.
{"title":"Partial Discharge Characteristics in Pre-Breakdown Processes of Oil-Pressboard Insulation with Needle-Plate Defect Under AC-DC Combined Voltage","authors":"Simeng Li, Qingquan Li, W. Si, Junyan Yao, Yalin Shi, T. Zhang","doi":"10.1109/EIC.2018.8481130","DOIUrl":"https://doi.org/10.1109/EIC.2018.8481130","url":null,"abstract":"The PD characteristics of oil-pressboard insulation with needle-plate defect at AC-DC combined voltage are unstable. In this paper, the time-variation trends of PD characteristics in pre-breakdown process at AC-DC combined voltage are studied via the tests in oil-pressboard insulation with needle-plate defect. The average PD repetition rate and average PD amplitude decrease with the PD developing, and the time-variation trends of them can be divided into fluctuation type and monotone type. The average PD amplitude has no obvious polarity effect, the average PD repetition rate has a polarity effect. In equivalent time-frequency spectrograms, most points move towards arch top with the developing of pre-breakdown processes, where PD equivalent time is 1300–1600 ns and PD equivalent frequency is 7.5-10 MHz. PD equivalent time-frequency spectrograms can be divided into half-arched type and whole-arched type at the end of pre-breakdown processes. The defect in pressboard caused by PD is a possible reason for the appearance of whole-arched time-frequency spectrogram.","PeriodicalId":184139,"journal":{"name":"2018 IEEE Electrical Insulation Conference (EIC)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123495139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.1109/eic.2018.8481112
F. Dollinger
At Haefely Hipotronics, we have seen and have even surprisingly discovered situations, in which tests were performed in an improper way: typically Murphy's Law. Various causes are involved, such as misinterpretation of standard (IEC/IEEE), or misinterpretation of the instrument settings, or inadequate instrumentation or test system. Performing tests improperly can lead measurements that do not conform to the applicable (IEC/IEEE) standard or may produce wrong measurement results, that may even damage the test object, test system, or cause injury to the operator. This presentation is a summary of some situations that have been seen onsite, covering tests like partial discharge measurement, loss measurement and lightning impulse test.
{"title":"Mitigating Murphy's Law While Test - Volume 1","authors":"F. Dollinger","doi":"10.1109/eic.2018.8481112","DOIUrl":"https://doi.org/10.1109/eic.2018.8481112","url":null,"abstract":"At Haefely Hipotronics, we have seen and have even surprisingly discovered situations, in which tests were performed in an improper way: typically Murphy's Law. Various causes are involved, such as misinterpretation of standard (IEC/IEEE), or misinterpretation of the instrument settings, or inadequate instrumentation or test system. Performing tests improperly can lead measurements that do not conform to the applicable (IEC/IEEE) standard or may produce wrong measurement results, that may even damage the test object, test system, or cause injury to the operator. This presentation is a summary of some situations that have been seen onsite, covering tests like partial discharge measurement, loss measurement and lightning impulse test.","PeriodicalId":184139,"journal":{"name":"2018 IEEE Electrical Insulation Conference (EIC)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122173276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-01DOI: 10.1109/EIC.2018.8481091
M. Hikita, Hikaru Mizoguchi, Tomohiro Kubo, Tomoki Uchimura, M. Kozako, Jintong Sun, A. Izumi, K. Karasawa, T. Ueno, T. Hirose, S. Hiroshima
Repetitive partial discharge inception voltage (RPDIV) measurement is indispensable for inverter-fed motor when testing the insulation dignity according to IEC 60034-18-41 IS. Our previous study showed detection sensitivity comparison among kinds of electromagnetic (EM) sensors for PD measurement in an actual motor core. This paper deals with an influence of the location of EM sensors on the sensitivity of detected EM wave to quantitatively evaluate RPDIV. As a result, it was found that employing the EM wave sensor located at the furthest position from the PD source on Z axis to detect PD can result in estimating higher RPDIV by 7.5 % at most than an actual one, depending on the sensor location. The possibility of location of a PD source using multiple LSs placed in the actual core is also suggested from differences in the signal strength and time for EM signal to reach multiple LSs.
{"title":"Influence of Electromagnetic Sensor Location on Repetitive Partial Discharge Inception Voltage in Actual Stator Core of Inverter Fed Motor","authors":"M. Hikita, Hikaru Mizoguchi, Tomohiro Kubo, Tomoki Uchimura, M. Kozako, Jintong Sun, A. Izumi, K. Karasawa, T. Ueno, T. Hirose, S. Hiroshima","doi":"10.1109/EIC.2018.8481091","DOIUrl":"https://doi.org/10.1109/EIC.2018.8481091","url":null,"abstract":"Repetitive partial discharge inception voltage (RPDIV) measurement is indispensable for inverter-fed motor when testing the insulation dignity according to IEC 60034-18-41 IS. Our previous study showed detection sensitivity comparison among kinds of electromagnetic (EM) sensors for PD measurement in an actual motor core. This paper deals with an influence of the location of EM sensors on the sensitivity of detected EM wave to quantitatively evaluate RPDIV. As a result, it was found that employing the EM wave sensor located at the furthest position from the PD source on Z axis to detect PD can result in estimating higher RPDIV by 7.5 % at most than an actual one, depending on the sensor location. The possibility of location of a PD source using multiple LSs placed in the actual core is also suggested from differences in the signal strength and time for EM signal to reach multiple LSs.","PeriodicalId":184139,"journal":{"name":"2018 IEEE Electrical Insulation Conference (EIC)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121614761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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