The reliability of electric supply to consumers is one of the most important factors that determine the requirements imposed on modem utility companies. This paper presents the results of investigation by computer sof...The reliability of electric supply to consumers is one of the most important factors that determine the requirements imposed on modem utility companies. This paper presents the results of investigation by computer software of the overvoltages resulting from a ferroresonance conditions in MV networks at open phase operating condition with and without connection to earth on source and load sides of distribution transformer. This overvoltage may reach 4.2 pu on one of the HV side of transformer unswitched phases. The results of the study show that ferroresonance overvoltage may be controlled by replacing fuses with circuit breakers on HV side to ensure switching-off all phases. Insertion of resistor or reactor in the neutral of source and loadsides of the transformer with 5% active load will help in suppressing overvoltages.展开更多
The field of stretchable electronics mainly includes electronic products conformal with tissues,being integrated into skin or clothing.Since these products need to work during deformation,their requirements for materi...The field of stretchable electronics mainly includes electronic products conformal with tissues,being integrated into skin or clothing.Since these products need to work during deformation,their requirements for materials focus on stretchability and conductivity.Liquid metals are excellent materials with these properties.However,liquid metals have extremely high surface tension at room temperature,which will spontaneously form a spherical shape and are difficult to form the shape required by stretchable devices,which is the biggest obstacle to their development in this emerging field.Therefore,the emphasis is placed on the principle of overcoming the high surface tension in this review,and various methods of using liquid metals to fabricate stretchable electronic devices based on these principles have been linked.Liquid metals show promise in the convenience of sensing,energy harvesting,etc.The existing challenges and opportunities are also discussed here.展开更多
文摘The reliability of electric supply to consumers is one of the most important factors that determine the requirements imposed on modem utility companies. This paper presents the results of investigation by computer software of the overvoltages resulting from a ferroresonance conditions in MV networks at open phase operating condition with and without connection to earth on source and load sides of distribution transformer. This overvoltage may reach 4.2 pu on one of the HV side of transformer unswitched phases. The results of the study show that ferroresonance overvoltage may be controlled by replacing fuses with circuit breakers on HV side to ensure switching-off all phases. Insertion of resistor or reactor in the neutral of source and loadsides of the transformer with 5% active load will help in suppressing overvoltages.
基金supported by the National Natural Science Foundation of China(52173237 and 51903068)the Natural Science Foundation of Heilongjiang Province,China(YQ2020E001)。
文摘The field of stretchable electronics mainly includes electronic products conformal with tissues,being integrated into skin or clothing.Since these products need to work during deformation,their requirements for materials focus on stretchability and conductivity.Liquid metals are excellent materials with these properties.However,liquid metals have extremely high surface tension at room temperature,which will spontaneously form a spherical shape and are difficult to form the shape required by stretchable devices,which is the biggest obstacle to their development in this emerging field.Therefore,the emphasis is placed on the principle of overcoming the high surface tension in this review,and various methods of using liquid metals to fabricate stretchable electronic devices based on these principles have been linked.Liquid metals show promise in the convenience of sensing,energy harvesting,etc.The existing challenges and opportunities are also discussed here.
