BEGIN:VCALENDAR VERSION:2.0 PRODID:IEEE vTools.Events//EN CALSCALE:GREGORIAN BEGIN:VTIMEZONE TZID:America/New_York BEGIN:DAYLIGHT DTSTART:20220313T030000 TZOFFSETFROM:-0500 TZOFFSETTO:-0400 RRULE:FREQ=YEARLY;BYDAY=2SU;BYMONTH=3 TZNAME:EDT END:DAYLIGHT BEGIN:STANDARD DTSTART:20221106T010000 TZOFFSETFROM:-0400 TZOFFSETTO:-0500 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=11 TZNAME:EST END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTAMP:20220716T012406Z UID:D7A4228D-98AE-4C68-9E0D-8155FC562519 DTSTART;TZID=America/New_York:20220708T120000 DTEND;TZID=America/New_York:20220708T140000 DESCRIPTION:The extension of power grid interconnection with an increased a mount of power flow control\, the long-distance transmission\, and the int egration of large blocks of wind\, solar and hydro powers all call for the accelerated development of high voltage direct current (HVDC) transmissio n. Despite the opportunities such as lower power loss\, higher capacity fo r a fixed corridor\, fully controllable power flow\, better transmission a nd stabilization capabilities between non-synchronized AC power systems\, and no length restriction because of free reactive power compensation\, th ere are still significant technical challenges for HVDC cabling systems. T he electric field distribution under DC voltage in the cylindrical cable i nsulation initiates with the Laplacian electric field distribution\; howev er\, the thermal gradient (TG) across the insulation and the change of the electrical conductivity because of its temperature dependence under loadi ng conditions will lead to the phenomenon of electric field inversion acro ss the dielectric. In addition\, the electric field distribution across a DC cable insulation is affected and often distorted by the accumulation of space charge. Therefore\, controlled electrical conductivity and highly s uppressed space charge accumulation are desired for tailoring the electric field across the cable insulation under DC. Full characterization and det ailed understanding of these properties as well as their correlation may b ring the ability to engineer needed dielectric properties for using as DC cable insulation. With respect to implications for practical material desi gn\, the study demonstrates that a polymer material with activation energi es in the range of 0.4 to 0.5 eV with relatively high trap density can be suitable for HVDC cable insulation.\n\nThe mass-impregnated (MI) insulatio ns have been used traditionally for DC cabling systems with line-commutate d converter (LCC) schemes. The MI insulations produced by a lapping proces s could be considered as a layered composite structure with excellent perf ormance under polarity reversal condition which is essential for changing the direction of power flow in LCC systems. Compared with MI insulation ca bles\, polymeric insulations such as crosslinked polyethylene (XLPE) insul ations are lighter\, less expensive\, and less harmful to the environment compared with MI insulation cables and can be manufactured by continuous e xtrusion process and conveniently extended during installation by oil-free pre-molded joints. However\, DC cables with XLPE insulation are only appl icable for the voltage source converter (VSC) systems. Therefore\, there s till exists the need for insulation with the advantages of both MI and pol ymeric insulations\, i.e.\, an extrudable insulation that is compatible wi th polarity reversal. A model DC material based on the ethylene propylene rubber (EPR) incorporated with 2D inorganic nanoclays is proposed. The DC electrical properties of the proposed material show large improvement in s pace charge suppression\, controlled electrical conductivity and consequen tly more uniform electric field distribution. Microstructure studies sugge st the uniform and oriented distribution of 2D nanoclay particles in EPR m atrix causes a desired trap distribution with high density of shallow trap s due to the presence of a high interfacial area between polymer chains an d nanoclay particles. The macroscopic effect of that is a significant redu ction of activation energy which contributes to controlling the charge tra nsport and suppressing the space charge accumulation in the composite diel ectrics. Results of the thermally stimulated depolarization current spectr a of the samples are in good agreement with the predicted trap distributio n based on the experimental results and morphological study.\n\nCo-sponsor ed by: IEEE DEIS M&C Co-chair - Jim Guo\n\nSpeaker(s): Mohamadreza \, \n\n Virtual: https://events.vtools.ieee.org/m/318272 LOCATION:Virtual: https://events.vtools.ieee.org/m/318272 ORGANIZER:ali.naderian@ieee.org SEQUENCE:4 SUMMARY:Novel solution for MVDC and HVDC cable insulation URL;VALUE=URI:https://events.vtools.ieee.org/m/318272 X-ALT-DESC:Description: <br /><p>The extension of power grid interconnectio n with an increased amount of power flow control\, the long-distance trans mission\, and the integration of large blocks of wind\, solar and hydro po wers all call for the accelerated development of high voltage direct curre nt (HVDC) transmission. Despite the opportunities such as lower power loss \, higher capacity for a fixed corridor\, fully controllable power flow\, better transmission and stabilization capabilities between non-synchronize d AC power systems\, and no length restriction because of free reactive po wer compensation\, there are still significant technical challenges for HV DC cabling systems. The electric field distribution under DC voltage in th e cylindrical cable insulation initiates with the Laplacian electric field distribution\; however\, the thermal gradient (TG) across the insulation and the change of the electrical conductivity because of its temperature d ependence under loading conditions will lead to the phenomenon of electric field inversion across the dielectric. In addition\, the electric field d istribution across a DC cable insulation is affected and often distorted b y the accumulation of space charge. Therefore\, controlled electrical cond uctivity and highly suppressed space charge accumulation are desired for t ailoring the electric field across the cable insulation under DC. Full cha racterization and detailed understanding of these properties as well as th eir correlation may bring the ability to engineer needed dielectric proper ties for using as DC cable insulation. With respect to implications for pr actical material design\, the study demonstrates that a polymer material w ith activation energies in the range of 0.4 to 0.5 eV with relatively high trap density can be suitable for HVDC cable insulation.</p>\n<p><br />The mass-impregnated (MI) insulations have been used traditionally for DC cab ling systems with line-commutated converter (LCC) schemes. The MI insulati ons produced by a lapping process could be considered as a layered composi te structure with excellent performance under polarity reversal condition which is essential for changing the direction of power flow in LCC systems . Compared with MI insulation cables\, polymeric insulations such as cross linked polyethylene (XLPE) insulations are lighter\, less expensive\, and less harmful to the environment compared with MI insulation cables and can be manufactured by continuous extrusion process and conveniently extended during installation by oil-free pre-molded joints. However\, DC cables wi th XLPE insulation are only applicable for the voltage source converter (V SC) systems. Therefore\, there still exists the need for insulation with t he advantages of both MI and polymeric insulations\, i.e.\, an extrudable insulation that is compatible with polarity reversal. A model DC material based on the ethylene propylene rubber (EPR) incorporated with 2D inorgani c nanoclays is proposed. The DC electrical properties of the proposed mate rial show large improvement in space charge suppression\, controlled elect rical conductivity and consequently more uniform electric field distributi on. Microstructure studies suggest the uniform and oriented distribution o f 2D nanoclay particles in EPR matrix causes a desired trap distribution w ith high density of shallow traps due to the presence of a high interfacia l area between polymer chains and nanoclay particles. The macroscopic effe ct of that is a significant reduction of activation energy which contribut es to controlling the charge transport and suppressing the space charge ac cumulation in the composite dielectrics. Results of the thermally stimulat ed depolarization current spectra of the samples are in good agreement wit h the predicted trap distribution based on the experimental results and mo rphological study.</p>\n<p>&nbsp\;&nbsp\;</p> END:VEVENT END:VCALENDAR