Perfluorocyclobutane(c-C4F8) has been recently considered as a potential alternative to SF6,because of its high electro-negativity and extremely low environmental effect.However,due to its high boiling point,c-C4F8 sh...Perfluorocyclobutane(c-C4F8) has been recently considered as a potential alternative to SF6,because of its high electro-negativity and extremely low environmental effect.However,due to its high boiling point,c-C4F8 should mixed with buffer gases such as N2 or CO2 in order to avoid the liquefaction at low temperature.This paper investigates insulating properties of c-C4F8/N2 gas mixtures from two aspects including electrical strength,and Global Warming Potential(GWP).Moreover,improved electrical breakdown model of gas mixtures is founded.Breakdown temperature and breakdown electrical field in gas mixtures can be obtained from rigorous Townsend criterion expression according to gas mixtures ratio and cross section data of gas mixtures in this model.Under the condition of different gas pressure(0.1~0.4 MPa),gas mixtures ratio(0～30%),and electrode gap(2~10 mm),breakdown voltages of gas mixtures are calculated by using of this model.Insulation strength of SF6/N2 mixed gas is compared with c-C4F8/N2 mixed gas in the same conditions.Research results show that theoretical computation corresponds with experiment.If the content of c-C4F8 or SF6 in mixtures is less than 30%,insulation strength between c-C4F8/N2 and SF6/N2 is very close.Considering two indexes(breakdown voltage,GWP),it is suitable for c-C4F8 content being 15%～20% in c-C4F8/N2 gas展开更多
针对目前很多型号的电动汽车电池管理系统(battery management system,BMS)与居民小区内的慢充充电桩不能正常通信的问题,依据确定性分析法,以倒序递推原则安排电动汽车的充电开始时间,研究了一种不采集电动汽车电池荷电状态(state of c...针对目前很多型号的电动汽车电池管理系统(battery management system,BMS)与居民小区内的慢充充电桩不能正常通信的问题,依据确定性分析法,以倒序递推原则安排电动汽车的充电开始时间,研究了一种不采集电动汽车电池荷电状态(state of charge,SOC)来实现小区内电动汽车群(aggregator)有序充电的控制方法,并以小区配电网为例,采用蒙特卡洛方法模拟用户到达时间,对电动汽车在无序充电、总负荷最低时段充电和倒序递推时段充电3种充电模式下配电变压器的负载情况进行了仿真和分析,结果表明,在倒序递推时段充电能显著减小电网峰谷差率,不会产生新的负荷尖峰,适用于实际应用。展开更多
基金Project Supported by the National Natural Science Foundation of China(No.:50777041)
文摘Perfluorocyclobutane(c-C4F8) has been recently considered as a potential alternative to SF6,because of its high electro-negativity and extremely low environmental effect.However,due to its high boiling point,c-C4F8 should mixed with buffer gases such as N2 or CO2 in order to avoid the liquefaction at low temperature.This paper investigates insulating properties of c-C4F8/N2 gas mixtures from two aspects including electrical strength,and Global Warming Potential(GWP).Moreover,improved electrical breakdown model of gas mixtures is founded.Breakdown temperature and breakdown electrical field in gas mixtures can be obtained from rigorous Townsend criterion expression according to gas mixtures ratio and cross section data of gas mixtures in this model.Under the condition of different gas pressure(0.1~0.4 MPa),gas mixtures ratio(0～30%),and electrode gap(2~10 mm),breakdown voltages of gas mixtures are calculated by using of this model.Insulation strength of SF6/N2 mixed gas is compared with c-C4F8/N2 mixed gas in the same conditions.Research results show that theoretical computation corresponds with experiment.If the content of c-C4F8 or SF6 in mixtures is less than 30%,insulation strength between c-C4F8/N2 and SF6/N2 is very close.Considering two indexes(breakdown voltage,GWP),it is suitable for c-C4F8 content being 15%～20% in c-C4F8/N2 gas
文摘针对目前很多型号的电动汽车电池管理系统(battery management system,BMS)与居民小区内的慢充充电桩不能正常通信的问题,依据确定性分析法,以倒序递推原则安排电动汽车的充电开始时间,研究了一种不采集电动汽车电池荷电状态(state of charge,SOC)来实现小区内电动汽车群(aggregator)有序充电的控制方法,并以小区配电网为例,采用蒙特卡洛方法模拟用户到达时间,对电动汽车在无序充电、总负荷最低时段充电和倒序递推时段充电3种充电模式下配电变压器的负载情况进行了仿真和分析,结果表明,在倒序递推时段充电能显著减小电网峰谷差率,不会产生新的负荷尖峰,适用于实际应用。
