The excellent reverse breakdown characteristics of Schottky barrier varactor(SBV)are crucially required for the application of high power and high efficiency multipliers.The SBV with a novel Schottky structure named m...The excellent reverse breakdown characteristics of Schottky barrier varactor(SBV)are crucially required for the application of high power and high efficiency multipliers.The SBV with a novel Schottky structure named metal-brim is fabricated and systemically evaluated.Compared with normal structure,the reverse breakdown voltage of the new type SBV improves from-7.31 V to-8.75 V.The simulation of the Schottky metal-brim SBV is also proposed.Three factors,namely distribution of leakage current,the electric field,and the area of space charge region are mostly concerned to explain the physical mechanism.Schottky metal-brim structure is a promising approach to improve the reverse breakdown voltage and reduce leakage current by eliminating the accumulation of charge at Schottky electrode edge.展开更多
Although the transmission efficiency of high-voltage high-frequency transformers improve as the rated frequency increases,their insulation performance is severely affected.Through a high-frequency experimental platfor...Although the transmission efficiency of high-voltage high-frequency transformers improve as the rated frequency increases,their insulation performance is severely affected.Through a high-frequency experimental platform,insulation tests on epoxy casting resins are carried out using high-frequency square wave signals.Subsequently,the variations of discharge inception and flashover voltages with frequency were analyzed based on the Secondary Electron Emission Avalanche(SEEA)model.The breakdown characteristics of epoxy casting resins are studied based on the Weibull distribution analysis and inverse power function model.Finally,an insulation test standard is proposed based on the breakdown characteristics of epoxy casting resins for dry-type HV-HF transformers.The results show that,the flashover voltages are noticeably reduced with the increase of frequency while the discharge inception is hardly affected by frequency.Moreover,the drop in breakdown voltages and insulation lifetime shortening are caused by high-frequency thermal effects.Also,the applied voltages of epoxy resin cast dry-type HV-HF transformers are recommended to be 3.27 to 3.49 times their maximum operating voltages in 1min applied withstand tests.The applied voltages of the induced withstand tests should be 2.20 to 2.52 times their maximum operating voltages.展开更多
文摘The excellent reverse breakdown characteristics of Schottky barrier varactor(SBV)are crucially required for the application of high power and high efficiency multipliers.The SBV with a novel Schottky structure named metal-brim is fabricated and systemically evaluated.Compared with normal structure,the reverse breakdown voltage of the new type SBV improves from-7.31 V to-8.75 V.The simulation of the Schottky metal-brim SBV is also proposed.Three factors,namely distribution of leakage current,the electric field,and the area of space charge region are mostly concerned to explain the physical mechanism.Schottky metal-brim structure is a promising approach to improve the reverse breakdown voltage and reduce leakage current by eliminating the accumulation of charge at Schottky electrode edge.
基金supported by the National Key R&D Program of China(2017YFB0903902)。
文摘Although the transmission efficiency of high-voltage high-frequency transformers improve as the rated frequency increases,their insulation performance is severely affected.Through a high-frequency experimental platform,insulation tests on epoxy casting resins are carried out using high-frequency square wave signals.Subsequently,the variations of discharge inception and flashover voltages with frequency were analyzed based on the Secondary Electron Emission Avalanche(SEEA)model.The breakdown characteristics of epoxy casting resins are studied based on the Weibull distribution analysis and inverse power function model.Finally,an insulation test standard is proposed based on the breakdown characteristics of epoxy casting resins for dry-type HV-HF transformers.The results show that,the flashover voltages are noticeably reduced with the increase of frequency while the discharge inception is hardly affected by frequency.Moreover,the drop in breakdown voltages and insulation lifetime shortening are caused by high-frequency thermal effects.Also,the applied voltages of epoxy resin cast dry-type HV-HF transformers are recommended to be 3.27 to 3.49 times their maximum operating voltages in 1min applied withstand tests.The applied voltages of the induced withstand tests should be 2.20 to 2.52 times their maximum operating voltages.
