阶次自适应AR等效电路模型的锂电池SOC滑模观测

基于等效电路模型的一类车载动力电池剩余荷电状态(state of charge，SOC)的估算方法，其估算精度高度依赖于模型精度，模型精度又正比于模型复杂度，以至于难以较好地应用于嵌入式控制单元.提出复杂度相对较低、能够自适应确定最优模型阶次的全新等效电路模型——基于阶次自适应AR模型的车载动力电池等效电路灰箱模型.基于此灰箱模型，给出锂离子电池SOC的滑模观测器设计推导及能观性、收敛性证明.结果表明，本文提出的基于阶次自适应AR等效电路灰箱模型的滑模观测器SOC估算方法(adaptive autoregressive-sliding mode observer，AAR-SMO)具有低模型复杂度、高精度、强鲁棒性及快速收敛等性能.     

Linear and non-linear pseudocapacitances with or without diffusion control

Pseudocapacitance is an important reversible charge storage mechanism in many electrode materials. Although the concept was first proposed in early 1960s, it has been more widely studied following the observation of rectangular cyclic voltammograms (CVs) when testing some transition metal oxides and electronically conducting polymers, and the association with supercapacitor. However, interpretation of pseudocapacitance is inconsistent in the literature. Although all agree that materials are pseudocapacitive if they undergo Faradaic reactions and exhibit rectangular CVs, some have regarded any surface confined Faradaic reactions which may present non-rectangular or even peak-shaped CVs to be pseudocapacitive. In the case of rectangular CVs, the amount of charge stored in the electrode is a linear function of the electrode potential, whilst for non-rectangular or peak-shaped CVs, the relationship is non-linear. It is shown in this article that only linear pseudocapacitance is of relevance to supercapacitor, but non-linear pseudocapacitance may find applications in rechargeable battery and supercapattery. Further, it is clarified that the equation i ​= ​k₁v ​+ ​k₂v^1/2 is useful in analysis of electrode kinetics in terms of surface confinement and diffusion control. However, this kinetic equation is blind to the thermodynamically determined charge storage mechanisms as shown by experimental evidence, and should not be used to differentiate non-capacitive Faradaic processes from pseudocapacitance, either linear or non-linear.     

Hollow bismuth ferrite combined graphene as advanced anode material for sodium-ion batteries

Hollow bismuth ferrite nanofibers were fabricated via simple electrospinning process,and the storage properties of Na-ions were investigated by atmospheric pressure X-ray photoelectron spectrum(APXPS) and Synchrotron Radiation.The results show that the hollow bismuth ferrite nanotubes demonstrate impressive sodium storage properties and good cycling stability that the specific capacity can exceed 500 mA h g~(-1) and the cycle number reaches several hundred cycles.The graphene-coated bismuth ferrite nanotubes exhibit a specific capacity of600 mAhg~(-1)and a 89% capacity retention after 200 cycles.The present strategy can be a significant step to fabricate hollow perovskite oxides and serve as sodium ion batteries.     

改进蚱蜢算法在电动汽车充换电站调度中的应用

电动汽车充换电站调度优化问题一般采用群智能优化算法求解，但现有算法存在陷入局部最优、早熟收敛等缺陷，因此提出一种改进的蚱蜢算法:采用边界反弹机制，提高算法效率;引入正余弦搜索机制，加强算法的全局搜索能力;采用Lévy飞行对粒子进行随机扰动，防止种群陷入局部最优;采用非线性收敛策略加快算法后期的收敛速度.实验结果表明，该算法在电动汽车充换电站调度优化问题上，性能优于原始蚱蜢算法以及其他现有群智能算法.     

水系负极材料磷酸钛锂的研究进展

介绍了水系锂离子电池的结构、原理、特点、发展现状,以及负极材料磷酸钛锂的特点,综述了磷酸钛锂性能提升改性方法,包括特殊结构改性、晶格掺杂、引入高效导电剂等磷酸钛锂的研究进展阐释了和发展前景.     

微囊饲料替代水蚯蚓对短须裂腹鱼仔鱼生长和存活的影响

以初始体质量为(15.5±1.65)mg的7日龄短须裂腹鱼仔鱼为试验对象,用微囊饲料对水蚯蚓的不同替代水平(0%、25%、50%、75%、100%)投喂28 d,通过测定全长、体质量、特定生长率、存活率来分析微囊饲料替代水蚯蚓对短须裂腹鱼仔鱼生长存活的影响。结果表明:微囊饲料替代水蚯蚓下特定生长率由高到低依次为0%替代组(5.73±0.08)25%替代组(4.80±0.28)50%替代组(4.67±0.28)75%替代组(4.18±0.51)100%替代组(3.13±0.20);存活率由高到低依次为75%替代水平组(77.83±6.11%)50%替代水平组(76.50±4.35%)25%替代水平组(71.33±4.01%)100%替代水平组(70.00±3.96%)0%替代水平组(64.00±6.61%)。综合分析,微囊饲料部分替代水蚯蚓在短须裂腹鱼培育中是苗种可行的,并且25%～50%的替代水平可以保持较快的生长和较高的成活率。     

FANUC OiT数控车床进给轴安装与调试

数控车床进给轴是用来执行直线定位和切削运动的装置,其性能的好坏直接决定了数控车床的加工精度。通过对进给轴安装调试与检测全过程的试验研究,分析了进给轴伺服系统的常见故障,指出了各类故障的排除方法,为数控机床的维护提供了技术参考。     

微进给机构的柔性铰链设计与有限元分析

设计一套以音圈电机为驱动电机,柔性铰链为支承元件,碟形弹簧为减震机构的微进给机构.柔性铰链采用双平行四杆机构的结构形式,计算了柔性铰链在音圈电机峰值推力作用下的最大输出位移和最大应力值.通过有限元分析柔性铰链在不同推力作用下的应力、应变图,发现在音圈电机最大推力800 N作用下,柔性铰链的最大应变为224.67μm.分析结果证明,所设计的直圆形双平行四连杆柔性铰链能够满足微进给机构的往复进给行程要求.     

我国发展纯电动汽车的SWOT分析简

我国纯电动汽车的发展,既有特有的优势和机会,也有威胁和劣势.只要制定正确的发展战略,发挥优势、利用机会、克服劣势、抵御威胁,通过各方面的共同努力,我们必然会迎来一个电动汽车的新时代.     

考虑运行工况的纯电动汽车动力传动系统参数设计

针对传统理论计算方法的不足,提出了一种理论计算与运行循环工况分析相结合的纯电动汽车动力传动系统的参数设计方法。根据整车动力性需求确定了电机的峰值功率。为使运行工况下电机尽可能工作在高效区,选取10种循环工况对整车需求功率范围进行分析,由此确定了电机的额定功率。分析了电池质量对整车动力性和续驶里程的影响,通过定义加速时间影响因子和续驶里程影响因子,修正了电机的功率参数。以整车动力性为约束,以等速工况下的续驶里程最大为目标对传动系速比进行优化,使整车的续驶里程在满足动力性的条件下明显提高。分析了蓄电池在不同SOC下输出功率的变化规律,当蓄电池SOC接近下限时,对电池组的输出功率进行了仿真分析,结果表明在极限工况下,蓄电池的输出功率可以满足整车的动力性要求。