新型磁控电抗器特性谐波研究

为了提高谐波抑制效果,提出了一种具有圆台型磁阀结构的磁控电抗器。根据电路等效的思想对提出的新型磁阀结构磁控电抗器进行了理论分析,推导了相应的磁化曲线,通过傅里叶变换建立了其输出谐波的数学模型,理论计算结果表明新型磁阀结构磁控电抗器的谐波特性优于传统磁控电抗器,并建立Matlab模型进行实例仿真,进一步讨论了该新型磁控电抗器的结构参数θ对其输出电流、各次谐波含量和响应时间的影响。     

TiO_2/ZnO/Ni_(0.5)Zn_(0.5)Fe_2O_4磁载光催化剂的制备及其光催化性能

采用均匀沉淀法制备了镍锌铁氧体、纳米TiO2-ZnO复合粉体和镍锌铁氧体负载纳米TiO2-ZnO复合粉体,并用XRD对所制粉体进行了表征。发现所制得的纳米TiO2为锐钛矿型、镍锌铁氧体为尖晶石型。以甲基橙溶液为模拟废水,考察了纳米TiO2-ZnO复合粉体和镍锌铁氧体负载纳米TiO2-ZnO复合粉体的光催化活性。研究还发现镍锌铁氧体负载纳米TiO2-ZnO粉体后仍具有良好的磁性能,可通过增加外磁场进行分离。     

磁悬浮刚性转子系统振动机理分析与动力学建模

磁悬浮惯性执行机构采用磁轴承支承,可通过主动控制实现极微振动,但磁悬浮惯性执行机构仍存在频谱分量丰富的振动.首先在转子动静不平衡和Sensor Runout振动机理分析的基础上,重点分析了Magnet Runout产生振动机理;然后,建立包含多振动源的系统动力学建模,并将整个动力学模型分解为平动和转动子系统,分析表明转子动静不平衡、Sensor Runout和Magnet Runout是通过不同的途径产生振动,不仅产生同频振动还包含倍频振动;最后,提出磁悬浮刚性转子系统主动振动控制的要求,为以后的主动振动控制研究奠定基础.     

磁悬浮飞轮转子不平衡力非线性抑制研究

磁悬浮飞轮转子由于其转子动力学特性所固有的强陀螺耦合效应,在干扰力作用下进动和章动2种涡动模态运动如果得不到有效的控制,会导致系统失稳。针对这一问题,提出了一种径向磁轴承的非线性控制方案,该方案把转子不平衡产生的不平衡力和不平衡力矩当作一种非线性干扰,对不平衡扰动力作用下的磁轴承-转子系统进行建模,设计了基于BP神经网络的非线性控制器,通过磁轴承电磁力对其进行抑制。仿真结果表明：设计的非线性控制器有效地实现了对不平衡扰动的补偿,提高了飞轮的失稳转速。     

永磁偏置径向磁轴承在磁悬浮反作用飞轮系统中的应用

针对现有径向磁轴承结构电励磁磁路耦合的缺陷,设计了一种新型径向永磁偏置混合磁轴承结构,介绍了这种轴承的结构特点和工作原理,并利用等效磁路法和有限元法(FEM)对该永磁偏置径向混合磁轴承进行了电磁分析,得出了磁轴承的数学模型和主要参数。研究结果表明,该径向永磁偏置磁轴承可以有效地避免磁路耦合现象,提高磁轴承系统的控制性能。     

基于波形自相关的磁控式并联电抗器合闸防误动方案

磁控式并联电抗器(MCSR)容量大范围平滑可调,是解决超/特高压电力系统无功、电压控制难题的有效措施,MCSR的安全稳定运行关系到系统的无功平衡和电压稳定。针对MCSR预励磁合闸导致基于总控电流基频分量的匝间故障保护误动的问题,提出了基于分相控制绕组电流波形自相关分析的合闸防误动方案。首先分析了MCSR在正常运行、预励磁合闸、匝间故障等工况下分相控制绕组电流的波形特征,利用计及了幅值差异的分相控制绕组电流及其延迟半周期的改进波形自相关系数,构成了合闸防误动方案,基于MATLAB/Simulink的仿真实验验证了方案的有效性。     

Experimental Study of Current Loss of Stainless Steel Magnetically Insulated Transmission Line with Current Density at MA/cm Level

A magnetically insulated transmission line （MITL） is used to transmit high power electric pulses in large pulse power systems. However, current loss is unavoidable, especially when the current density is up to 1 MA/cm. In the paper, the current loss of an MITL made of stainless steel, which is usually used in large pulse power generators, is experimentally studied, and possible mechanisms to explain the current loss of the MITL are analyzed and discussed. From the experimental results, the relationship between loss current density and input current density follows approximately a power law. The loss is also related to the configuration of the MITL.     

Integrated power and single axis attitude control system with two flywheels

The existing research of the integrated power and attitude control system(IPACS) in satellites mainly focuses on the IPACS concept,which aims at solving the coupled problem between the attitude control and power tracking.In the IPACS,the configuration design of IPACS is usually not considered,and the coupled problem between two flywheels during the attitude control and energy storage has not been resolved.In this paper,an integrated power and single axis attitude control system using two counter rotating magnetically suspended flywheels mounted to an air table is designed.The control method of power and attitude control using flywheel is investigated and the coupling problem between energy storage and attitude control is resolved.A computer simulation of an integrated power and single axis attitude control system with two flywheels is performed,which consists of two counter rotating magnetically suspended flywheels mounted to an air rotary table.Both DC bus and a single axis attitude are the regulation goals.An attitude & DC bus coordinator is put forward to separate DC bus regulation and attitude control problems.The simulation results of DC bus regulation and attitude control are presented respectively with a DC bus regulator and a simple PD attitude controller.The simulation results demonstrate that it is possible to integrate power and attitude control simultaneously for satellite using flywheels.The proposed research provides theory basis for design of the IPACS.     

用于XRF测量微量Np的磁助分离制样方法

建立磁助捕集分离制样法,使用超顺磁性TiOA固相捕集剂捕集溶液中的镎,利用外加磁场快速分离制样,实现捕集、分离及制样同时完成,可直接使用X射线荧光测量样品中Np的含量。研究了反应时间、固相捕集剂用量、液相体积及酸度等因素对测量的影响,给出了推荐测量分析流程。使用磁助捕集分离制样,对Np的质量检出下限为0.12μg,质量浓度检出下限为0.04mg/L,满足Purex流程3EU工艺点测量Np的要求。