直流故障字典自动生成系统研究

介绍了赢流故障字典自动生成系统的设计及其他用的关键技术。设计了以SPICE稃序为基础的电路故障仿真器，分析了基于最小错误慨率的模糊集划分方法，讨论了基于故障状态编码的节点优化选择方法，进而实现了直流故障字典的自动生成。     

直流电动机换向不良的分析与处理

通过对直流电机运行过程中换向不良的原因分析,从机械性原因和电磁性原因2方面,有针对性地提出改进和调整方法.     

直流接触器烧损原因分析及检修工艺

介绍了某型直流接触器的工作原理,分析了接触器烧损的原因,并对检修工艺提出了建议。     

电动汽车动力电源系统DC／DC变换器的匹配和计算

介绍新能源汽车DC／DC变换器在实际应用中的匹配、选型思路及方法。     

上海地铁直流列车辅助逆变器起动失效分析及解决措施

针对上海轨道交通一号线直流电动列车因蓄电池应急供电后产生电压跌落,造成车辆辅助逆变器起动失效,导致列车丧失运营能力的故障,进行故障原因查找与分析研究,并提出解决措施。     

宽电刷直流电机电磁转矩算法

电刷宽度对直流电机电磁转矩的影响是很大的，因此，在未考虑电刷宽度的条件下所推导出的电磁转矩计算式不够精确，对直流电机尤其是宽电刷直流电机的设计缺乏指导意义。作者详细分析了电刷宽度对直流电机电磁转矩的影响，给出了直流电机电磁转矩的计算方法。实验证明该计算方法更精确、对直流电机设计更具有指导意义。     

A simplified method to predict grounding damage of double bottom tankers

This paper presents a set of analytical expressions for the calculation of damage opening sizes in tanker groundings. The simplified formulas were given for the grounding force, longitudinal structural damage and the opening width in the inner and outer plating of a tanker's double bottom. The simplified formulas derived are based on a set of numerical simulations conducted with tankers of different dimensions- 120, 190 and 260 m in length. The simulations were performed for five penetration depths and for several rock/ground topologies.The formula for the horizontal grounding force was derived provided the grounding force is proportional to the contact area and the contact pressure. By use of regression analysis it was shown that the contact pressure for any combination of ship and rock size can be expressed with a single normalized polynomial. The actual contact pressure was found by scaling the normalized pressure with the structural resistance coefficient. Given the formulation for the normalized contact pressure, the actual contact force for a ship can be found as a product of average contact pressure and the contact area.The longitudinal length of the damage was evaluated based on the average contact force and the kinetic energy of the ship. The damage opening widths in the outer and inner bottom of the ship were derived separately for two ranges of relative rock sizes as they have strong influence on the deformation mode. The damage widths were given as a function of rock size, penetration depth and double bottom height. To improve the prediction of the onset of the inner bottom failure, a critical relative penetration depth as a function of the ratio of the rock size and the ship breadth was established.Comparison to the numerical simulations showed that the derived simplified approach describes the horizontal grounding force and the damage length well for the penetration depths above 0.5 m. For the range of specified relative rock sizes, the damage width in the inner and outer bottom deviates from numerical simulations approximately up to 25%, which was considered sufficient for the analyses where rapid damage assessment is needed. Comparison was also made to real accidental damage data and to the results of several simplified formulas.     

无刷直流推进电动机稳态性能的仿真

建立无刷直流推进电动机的稳态仿真数学模型,利用特征向量法以及对称性边界条件进行求解,得到定子三相电流的稳态解,并与动态仿真的结果进行对比,验证了该方法的正确性。     

上海轨道交通直流电力电缆的故障分析

直流1500V电缆是保障地铁正常运行的关键设施。介绍了上海地铁直流电缆的敷设方式和环境,在统计历史故障的基础上对直流电缆故障进行了分类,提出了在新线建设和改造项目中,尽可能采用带铠装的软电缆;通过在线检测手段,建立专家评估系统,评定绝缘的优劣并预警其劣化的趋势;改进直流电缆敷设质量,改善其运行环境等措施和建议。     

解决DC01型电动列车辅助逆变器起动失效的专用DC/DC升压变换器研制

针对上海地铁DC01型电动列车因蓄电池应急供电后产生电压跌落,造成车辆辅助逆变器起动失效,导致列车丧失运营能力的故障,提出加装专用DC/DC升压变换器的解决方案。介绍了DC/DC升压变换器的研制及其模拟试验和车上试验。试验表明DC/DC升压变换器能确保辅助逆变器正常起动。