After current zero,which is the moment when the vacuum circuit breaker interrupts a vacuum arc,sheath development is the first process in the dielectric recovery process.An axial magnetic field（AMF） is widely used i...After current zero,which is the moment when the vacuum circuit breaker interrupts a vacuum arc,sheath development is the first process in the dielectric recovery process.An axial magnetic field（AMF） is widely used in the vacuum circuit breaker when the high-current vacuum arc is interrupted.Therefore,it is very important to study the influence of different AMF amplitudes on the sheath development.The objective of this paper is to study the influence of different AMF amplitudes on the sheath development from a micro perspective.Thus,the particle in cell-Monte Carlo collisions（PIC-MCC） method was adopted to develop the sheath development model.We compared the simulation results with the experimental results and then validated the simulation.We also obtained the speed of the sheath development and the energy density of the ions under different AMF amplitudes.The results showed mat the larger the AMF amplitudes are,the faster the sheath develops and the lower the ion energy density is,meaning the breakdown is correspondingly more difficult.展开更多
The article describes design peculiarities of the novel compact vacuum circuit breaker with rated voltage 40.5 kV. The design incorporates several novel technical solutions： polycarbonate support insulation, mono-sta...The article describes design peculiarities of the novel compact vacuum circuit breaker with rated voltage 40.5 kV. The design incorporates several novel technical solutions： polycarbonate support insulation, mono-stable magnetic actuator, labyrinth pulling insulator, core-type flexible contact and new compact vacuum interrupter （VI）. Phases are encapsulated into silicone rubber providing required creepage distance and excellent tracking resistance. These novelties along with extensive modeling of the mechanical and electrical fields followed by design optimization resulted in weight reduction of more than 50% compared with alternatives available in the market. And this is in spite of built in sensors measuring： phase currents, zero-sequence current, phase voltages.展开更多
In order to get an insight into residual plasma radial motion during the post-arc stage,a twodimensional(2D)cylindrical particle-in-cell(PIC)model is developed.Firstly,influences of a virtual boundary condition on the...In order to get an insight into residual plasma radial motion during the post-arc stage,a twodimensional(2D)cylindrical particle-in-cell(PIC)model is developed.Firstly,influences of a virtual boundary condition on the residual plasma motion are studied.For purpose of validating this 2D cylindrical particle-in-cell model,a comparison between one-dimensional particle-in-cell model is also presented in this paper.Then a study about the influences of the rising rate of transient recovery voltage on the residual plasma radial motion is presented on the basis of the 2D PIC model.展开更多
When interrupting short circuit fault by 40.5-kV vacuum circuit breakers, it is significant to eliminate multiple restrike phenomena, which occur frequently and result in high overvoltage and even interruption failure...When interrupting short circuit fault by 40.5-kV vacuum circuit breakers, it is significant to eliminate multiple restrike phenomena, which occur frequently and result in high overvoltage and even interruption failure. A synthetic circuit that can supply a DC recovery voltage after current zero was used to study multiple restrike phenomena in switching. Some key factors including breaking current, clearance between open contacts, electrode structure and contact material, which may affect restrike characteristics, were studied. Under various clearances, the statistical probability of restrike was obtained. As a result, the best scope of clearance between open contacts was found. The performance of CuCr50/50 and CuCr75/25 material were compared. Two kinds of electrode structures, namely 1/2 coil structure and cup-shaped axial magnetic structure, were tested. After a high-current interruption, conditioning effoct was realized and the probability of restrike decreased.展开更多
基金supported by the National Key Basic Research Program of China(973 Program) 2015CB251002National Natural Science Foundation of China under Grant 51521065, 51577145,51377128,51323012,51607135+3 种基金Program of State Grid Electrical Power Research Institute GY71-14-004the Science and Technology Project Funds of the Grid State Corporation(Medium voltage DC distribution protection) (SGSNKYOOKJJS1501564)the Science and Technology Project Funds of Hubei Electric Power Company(SGRIZLKJ (2016)325)State Key Laboratory of Electrical Insulation and Power Equipment(EIPE17305)
文摘After current zero,which is the moment when the vacuum circuit breaker interrupts a vacuum arc,sheath development is the first process in the dielectric recovery process.An axial magnetic field（AMF） is widely used in the vacuum circuit breaker when the high-current vacuum arc is interrupted.Therefore,it is very important to study the influence of different AMF amplitudes on the sheath development.The objective of this paper is to study the influence of different AMF amplitudes on the sheath development from a micro perspective.Thus,the particle in cell-Monte Carlo collisions（PIC-MCC） method was adopted to develop the sheath development model.We compared the simulation results with the experimental results and then validated the simulation.We also obtained the speed of the sheath development and the energy density of the ions under different AMF amplitudes.The results showed mat the larger the AMF amplitudes are,the faster the sheath develops and the lower the ion energy density is,meaning the breakdown is correspondingly more difficult.
文摘The article describes design peculiarities of the novel compact vacuum circuit breaker with rated voltage 40.5 kV. The design incorporates several novel technical solutions： polycarbonate support insulation, mono-stable magnetic actuator, labyrinth pulling insulator, core-type flexible contact and new compact vacuum interrupter （VI）. Phases are encapsulated into silicone rubber providing required creepage distance and excellent tracking resistance. These novelties along with extensive modeling of the mechanical and electrical fields followed by design optimization resulted in weight reduction of more than 50% compared with alternatives available in the market. And this is in spite of built in sensors measuring： phase currents, zero-sequence current, phase voltages.
基金supported in part by National Natural Science Foundation of China(Nos.51807148 and U1866202)in part by China Postdoctoral Science Foundation(No.2019M653628)。
文摘In order to get an insight into residual plasma radial motion during the post-arc stage,a twodimensional(2D)cylindrical particle-in-cell(PIC)model is developed.Firstly,influences of a virtual boundary condition on the residual plasma motion are studied.For purpose of validating this 2D cylindrical particle-in-cell model,a comparison between one-dimensional particle-in-cell model is also presented in this paper.Then a study about the influences of the rising rate of transient recovery voltage on the residual plasma radial motion is presented on the basis of the 2D PIC model.
文摘When interrupting short circuit fault by 40.5-kV vacuum circuit breakers, it is significant to eliminate multiple restrike phenomena, which occur frequently and result in high overvoltage and even interruption failure. A synthetic circuit that can supply a DC recovery voltage after current zero was used to study multiple restrike phenomena in switching. Some key factors including breaking current, clearance between open contacts, electrode structure and contact material, which may affect restrike characteristics, were studied. Under various clearances, the statistical probability of restrike was obtained. As a result, the best scope of clearance between open contacts was found. The performance of CuCr50/50 and CuCr75/25 material were compared. Two kinds of electrode structures, namely 1/2 coil structure and cup-shaped axial magnetic structure, were tested. After a high-current interruption, conditioning effoct was realized and the probability of restrike decreased.
