We review the short-circuit testing of distribution and power transformers, and include a list of 110-220kV power transformers tested up to February 2002.
Lithium iron phosphate batteries have been increasingly utilized in recent years because their higher safety performance can improve the increasing trend of recurring thermal runaway accidents.However,the safety perfo...Lithium iron phosphate batteries have been increasingly utilized in recent years because their higher safety performance can improve the increasing trend of recurring thermal runaway accidents.However,the safety performance and mechanism of high-capacity lithium iron phosphate batteries under internal short-circuit challenges remain to be explored.This work analyzes the thermal runaway evolution of high-capacity LiFePO_(4) batteries under different internal heat transfer modes,which are controlled by different penetration modes.Two penetration cases involving complete penetration and incomplete penetration were detected during the test,and two modes were performed incorporating nails that either remained or were removed after penetration to comprehensively reveal the thermal runaway mechanism.A theoretical model of microcircuits and internal heat conduction is also established.The results indicated three thermal runaway evolution processes for high-capacity batteries,which corresponded to the experimental results of thermal equilibrium,single thermal runaway,and two thermal runaway events.The difference in heat distribution in the three phenomena is determined based on the microstructure and material structure near the pinhole.By controlling the heat dissipation conditions,the time interval between two thermal runaway events can be delayed from 558 to 1417 s,accompanied by a decrease in the concentration of in-situ gas production during the second thermal runaway event.展开更多
过电流关断试验是柔性直流输电(voltage sourced converter based high voltage direct current transmission,VSC-HVDC)换流阀暂态试验之一,是为了检验换流阀设计的正确性及对桥臂直通工况应力耐受性进行的试验。研究阀过电流关断试验...过电流关断试验是柔性直流输电(voltage sourced converter based high voltage direct current transmission,VSC-HVDC)换流阀暂态试验之一,是为了检验换流阀设计的正确性及对桥臂直通工况应力耐受性进行的试验。研究阀过电流关断试验的试验方法,分析桥臂直通工况下的应力,提出等效试验方法并设计试验电路,最后给出试验电路中阀的应力波形与实际工况下应力波形的对比,结合关键应力等效性分析,验证试验方法和试验电路的等效性。展开更多
文摘We review the short-circuit testing of distribution and power transformers, and include a list of 110-220kV power transformers tested up to February 2002.
基金supported by the National Key R&D Program of China(2021YFB2402001)the China National Postdoctoral Program for Innovative Talents(BX20220286)+1 种基金the China Postdoctoral Science Foundation(2022T150615)supported by the Youth Innovation Promotion Association CAS(Y201768)。
文摘Lithium iron phosphate batteries have been increasingly utilized in recent years because their higher safety performance can improve the increasing trend of recurring thermal runaway accidents.However,the safety performance and mechanism of high-capacity lithium iron phosphate batteries under internal short-circuit challenges remain to be explored.This work analyzes the thermal runaway evolution of high-capacity LiFePO_(4) batteries under different internal heat transfer modes,which are controlled by different penetration modes.Two penetration cases involving complete penetration and incomplete penetration were detected during the test,and two modes were performed incorporating nails that either remained or were removed after penetration to comprehensively reveal the thermal runaway mechanism.A theoretical model of microcircuits and internal heat conduction is also established.The results indicated three thermal runaway evolution processes for high-capacity batteries,which corresponded to the experimental results of thermal equilibrium,single thermal runaway,and two thermal runaway events.The difference in heat distribution in the three phenomena is determined based on the microstructure and material structure near the pinhole.By controlling the heat dissipation conditions,the time interval between two thermal runaway events can be delayed from 558 to 1417 s,accompanied by a decrease in the concentration of in-situ gas production during the second thermal runaway event.
文摘过电流关断试验是柔性直流输电(voltage sourced converter based high voltage direct current transmission,VSC-HVDC)换流阀暂态试验之一,是为了检验换流阀设计的正确性及对桥臂直通工况应力耐受性进行的试验。研究阀过电流关断试验的试验方法,分析桥臂直通工况下的应力,提出等效试验方法并设计试验电路,最后给出试验电路中阀的应力波形与实际工况下应力波形的对比,结合关键应力等效性分析,验证试验方法和试验电路的等效性。
