The demand for high safety and high reliability lithium-ion batteries(LIBs)is strongly considered for practical applications.However,due to their inherent self-discharge properties or abuse,LIBs face the threat of ove...The demand for high safety and high reliability lithium-ion batteries(LIBs)is strongly considered for practical applications.However,due to their inherent self-discharge properties or abuse,LIBs face the threat of over-discharge,which induces premature end of life and increased risk of thermal runaway.In addition,a strong demand for batteries with zero-volt storage is strongly considered for aerospace and implantable medical devices.In this review,we firstly introduce the necessity and the importance of over-discharge and zero-volt protection for LIBs.The mechanism of damage to the Cu current collectors and SEI induced by potential changes during over-discharge is presented.The current over-discharge protection strategies based on whether the zero-crossing potential of the electrodes is summarized.Finally,the fresh insights into the material design of cathode prelithiation additives are presented from the perspective of over-discharge protection.展开更多
提出一簇基于零电压零电流脉宽调制(pulse width-modulation,PWM)开关单元的新型零电压零电流(zero-current and zero-volt-age switching,ZC-ZVS)PWM变换器。新型零电压零电流PWM变换器的主开关工作在零电流开关状态,辅助开关工作在零...提出一簇基于零电压零电流脉宽调制(pulse width-modulation,PWM)开关单元的新型零电压零电流(zero-current and zero-volt-age switching,ZC-ZVS)PWM变换器。新型零电压零电流PWM变换器的主开关工作在零电流开关状态,辅助开关工作在零电压开关状态,无源器件二极管工作在零电流状态。新型变换器工作频率恒定,减少了换流损耗。与硬开关变换器相比,新型零电压零电流变换器主开关的电流电压应力都没有增加。分析新型零电压零电流BOOST变换器的工作原理。仿真结果验证这簇新型零电压零电流变换器的可行性。展开更多
在研究配电网的电弧接地故障、断路器投切电弧及电弧炉电气特性时,多数学者通常使用恒电阻、Cassie、Mayr电弧模型,三者都具有片面性,将Cassie与Mayr两个电弧模型结合使用可以达到互补。在ATP-EMTP平台下将两种电弧模型进行组合搭建,并...在研究配电网的电弧接地故障、断路器投切电弧及电弧炉电气特性时,多数学者通常使用恒电阻、Cassie、Mayr电弧模型,三者都具有片面性,将Cassie与Mayr两个电弧模型结合使用可以达到互补。在ATP-EMTP平台下将两种电弧模型进行组合搭建,并合理设置参数,通过在中性点非有效接地10 k V配电网下的仿真,研究分析了电弧的电压分布、过零点、伏安特性,证明该电弧模型可正确反映中性点非有效接地配电网故障电弧特性。展开更多
基金supported by the Beijing Natural Science Foundation(L233004)National Natural Science Foundation of China(62071274 and 22393900)+2 种基金National Key Research and Development Program of China(2021YFB2400300)Shuimu Tsinghua Scholar ProgramTsinghua University Initiative Scientific Research Program.
文摘The demand for high safety and high reliability lithium-ion batteries(LIBs)is strongly considered for practical applications.However,due to their inherent self-discharge properties or abuse,LIBs face the threat of over-discharge,which induces premature end of life and increased risk of thermal runaway.In addition,a strong demand for batteries with zero-volt storage is strongly considered for aerospace and implantable medical devices.In this review,we firstly introduce the necessity and the importance of over-discharge and zero-volt protection for LIBs.The mechanism of damage to the Cu current collectors and SEI induced by potential changes during over-discharge is presented.The current over-discharge protection strategies based on whether the zero-crossing potential of the electrodes is summarized.Finally,the fresh insights into the material design of cathode prelithiation additives are presented from the perspective of over-discharge protection.
文摘提出一簇基于零电压零电流脉宽调制(pulse width-modulation,PWM)开关单元的新型零电压零电流(zero-current and zero-volt-age switching,ZC-ZVS)PWM变换器。新型零电压零电流PWM变换器的主开关工作在零电流开关状态,辅助开关工作在零电压开关状态,无源器件二极管工作在零电流状态。新型变换器工作频率恒定,减少了换流损耗。与硬开关变换器相比,新型零电压零电流变换器主开关的电流电压应力都没有增加。分析新型零电压零电流BOOST变换器的工作原理。仿真结果验证这簇新型零电压零电流变换器的可行性。
文摘在研究配电网的电弧接地故障、断路器投切电弧及电弧炉电气特性时,多数学者通常使用恒电阻、Cassie、Mayr电弧模型,三者都具有片面性,将Cassie与Mayr两个电弧模型结合使用可以达到互补。在ATP-EMTP平台下将两种电弧模型进行组合搭建,并合理设置参数,通过在中性点非有效接地10 k V配电网下的仿真,研究分析了电弧的电压分布、过零点、伏安特性,证明该电弧模型可正确反映中性点非有效接地配电网故障电弧特性。
