Initial Rotor Position Detection of 12/10 Flux-switching Permanent Magnet Motors

电机转子初始位置检测的精度直接决定其启动运行时的性能。针对12/10极永磁磁通切换型电机,在验证其凸极性的基础上,采用注入脉振高频信号实现转子初始位置估计。通过对传统高频脉振正弦电压信号注入的分析,研究了基于高频方波或三角波的注入方法,再利用电流差值调制或直接信号调制方法得到位置误差信号,同时根据磁路的饱和效应,通过对d轴电流过零点时间差值的累加,实现了磁极方向辨识。分析了位置误差信号的系数与初始位置检测收敛性的关系。通过实验验证了所提方法的正确性和可行性。

Influence of Inner/Outer Stator Pole Ratio and Relative Position on Electromagnetic Performance of Partitioned Stator Switched Flux Permanent Magnet Machines

Based on the 6-pole outer stator(armature winding-stator),the influence of inner(permanent magnet-stator)/outer stator pole ratio n(n=NIS/NOS),stator relative positions and rotor pole number combinations on electromagnetic performance of partitioned stator switched flux permanent magnet(PM)machines(PS-SFPMMs)is investigated in this paper.Since the armature windings and PMs are located in two separated stators and PMs are stationary,PS-SFPMMs have high fault tolerance capabilities.To maximize the torque performance,the PM of inner stator pole should be aligned with outer stator pole when n is odd while the iron rib of inner stator pole should be aligned with outer stator pole when n is even.No matter what n is selected,the rotor pole number NR can be any integers except the phase number and its multiples.The analysis results indicate that the optimal NR is closed to(NIS+NOS)/2 and it is odd when n is odd while it is even when n is even.Meanwhile,symmetrical phase back-EMF waveform will be obtained when the ratio of Min(NOS,NIS)to the greatest common divisor of Min(NOS,NIS)and NR is even.Based on the optimal rotor pole numbers for 6-pole outer stator with different n and corresponding optimal relative position together with same rated copper loss,the average torque is improved by 18.4%,25.1%and 25.7%respectively in PS-SFPMMs with n equal to 2,3 and 4 when compared with PS-SFPMM with n equal to 1.The analyses are validated by experiment results of the prototype machine.

Stability and Robust Stability of Switched Positive Linear Systems With All Modes Unstable

This paper is concerned with the stability and robust stability of switched positive linear systems(SPLSs) whose subsystems are all unstable. By means of the mode-dependent dwell time approach and a class of discretized co-positive Lyapunov functions, some stability conditions of switched positive linear systems with all modes unstable are derived in both the continuous-time and the discrete-time cases, respectively. The copositive Lyapunov functions constructed in this paper are timevarying during the dwell time and time-invariant afterwards. In addition, the above approach is extended to the switched interval positive systems. A numerical example is proposed to illustrate our approach.

Speed-assigned Position Tracking Control of SRM With Adaptive Backstepping Control

A novel speed-assigned method is applied to the position tracking control of switched reluctance motor(SRM).A speed control freedom can be drawn into the position control through speed assignment. Adaptive backstepping control is used to design the position controller for the SRM. The accuracy of position tracking of the SRM can be enhanced with speed assignment. A disturbance observer is further designed to enhance the estimation accuracy of the unknown load torque. Simulation results certify that the design scheme is right and effective.

Detecting the Position of the Moving-iron Solenoid by Non-displacement Sensor Based on Parameter Identification of Flux Linkage Characteristics

Currently, most researches use signals, such as the coil current or voltage of solenoid, to identify parameters; typically, parameter identification method based on variation rate of coil current is applied for position estimation. The problem exists in these researches that the detected signals are prone to interference and difficult to obtain. This paper proposes a new method for detecting the core position by using flux characteristic quantity, which adds a new group of secondary winding to the coil of the ordinary switching electromagnet. On the basis of electromagnetic coupling theory analysis and simulation research of the magnetic field regarding the primary and secondary winding coils, and in accordance with the fact that under PWM control mode varying core position and operating current of windings produce different characteristic of flux increment of the secondary winding. The flux increment of the electromagnet winding can be obtained by conducting time domain integration for the induced voltage signal of the extracted secondary winding, and the core position from the two-dimensional fitting curve of the operating winding current and flux-linkage characteristic quantity of solenoid are calculated. The detecting and testing system of solenoid core position is developed based on the theoretical research. The testing results show that the flux characteristic quantity of switching electromagnet magnetic circuit is able to effectively show the core position and thus to accomplish the non-displacement transducer detection of the said core position of the switching electromagnet. This paper proposes a new method for detecting the core position by using flux characteristic quantity, which provides a new theory and method for switch solenoid to control the proportional valve.

关于正切换系统的共同线性copositive Lyapunov函数

研究了正线性系统的共同线性copositive Lyapunov函数。首先,基于几何性质给出了关于一对二阶正线性系统的定理的另一种证明。通过新的证明方法,把结果推广到有限个二阶正线性系统的情况.然后对三阶情况给出了一个结果。最后,对高阶的正线性系统给出了一些结果。

基于DPA-Switch的蓄电池供电系统开关电源设计

采用美国Power Integration(PI)公司的单片集成DC-DC开关电源芯片DPA-Switch,设计并制作了一种DC-DC反激式高频开关电源,能够在12～48V电压等级蓄电池供电的电力电子系统中作为控制电源。介绍了以DPA-Switch系列DPA425芯片作为控制核心的开关电源的工作原理,着重讨论了工作频率达400kHz的高频变压器的设计与制作。研究结果表明,该电源能够在12～48V电压等级蓄电池系统中稳定工作,输出±15V(0.3A)和±5V(0.5A)四路直流电压,各路输出电压波动小于5%,满足设计要求,该开关电源具有较好的工程实用性。

Asynchronous Observer Design for Switched Linear Systems: A Tube-Based Approach

This paper proposes a tube-based method for the asynchronous observation problem of discrete-time switched linear systems in the presence of amplitude-bounded disturbances.Sufficient stability conditions of the nominal observer error system under mode-dependent persistent dwell-time(MPDT)switching are first established. Taking the disturbances into account, a novel asynchronous MPDT robust positive invariant(RPI) set and an asynchronous MPDT generalized RPI(GRPI)set are determined for the difference system between the nominal and disturbed observer error systems. Further, the global uniform asymptotical stability of the observer error system is established in the sense of converging to the asynchronous MPDT GRPI set, i.e., the cross section of the tube of the observer error system. Finally, the proposed results are validated on a space robot manipulator example.

A Study on the Molecular Switch of Gene Expression of the Mouse Heart Nuclear DNA Fragments

It is observed by in situ stain that LDH (1 5) ...nNAD + can probably enter the nucleopore and can be bound bound specifically with the genes that encode them. During the in vitro expression, the dilution of heart nuclear DNA fragments could enhance the expression activity of LDH/DNA and the amount of expressed LDH (1 5) is in proportion to the amount of dissociable LDH (1 5) on the LDH/DNA. With the integration of 14C Leu to the proteins, it is also observed that the addition of LDH (1 5) ...nNAD + can suppress the in vitro expression activity of LDH/DNA. AFM observation shows that the regulation sequence at the both ends of active genes may be bound with such active factors as proteins encoded by the genes which probably is the main molecular switch of gene expression and regulation we have been always searching for. Our work shows the prospective application of the combination of AFM and isotope labeling in the research of biological reaction.

动态无线充电系统自解耦型分段导轨及其双模切换策略研究

为抑制电动汽车动态无线充电系统发射单元间的交叉耦合,降低其对系统谐振参数设计的影响,文中利用螺线管线圈与平面线圈正交解耦特性,提出一种自解耦分段发射导轨,其中螺线管为分级叠层绕制,实现了相邻发射单元间的自解耦。为降低系统输出参数波动,基于互感动态变化规律,确定系统最佳充电区间,并提出一种双模工作模式及其分段切换策略,实现对发射线圈实能顺序的实时控制。为实现双模工作状态的有序变换,设计自解耦检测线圈结构,该检测线圈采用单层螺线管绕制并与接收线圈正交,避免检测信号与电能传输之间的干扰。最后,搭建实验平台对所提方法的有效性进行验证。实验结果表明,系统输出功率平稳性提升了19.5%,系统的最高效率可达92.3%。

A 2.4 GHz Switched Beam Antenna for Indoor Applications Using Angle of Arrival Estimation

This study introduces a new design of planar antenna array for ISM band applications at 2.4 GHz. This prototype is switched beam antenna, namely planar antenna with four meandered slotted triangular elements (PAFMSTE), which is proposed for wireless indoor applications. The Base Station (BS) equipped with this planar antenna is preferred to be at the center position on the room ceiling to cover all sectors of the room. It is designed to use four directional triangular elements arranged to form a square planar antenna array. The PAFMSTE is used to obtain optimal directivity in four directions in azimuth plane with 3 dB beamwidth of 90°at a specific orientation of 30°in elevation plane. Switched parasitic technique is used to enable PAFMSTE to steer a directional beam through four locations by using four PIN diodes switches. The High Frequency Structure Simulator (HFSS) is used as an efficient simulation tool to optimize the performance of the PAFMSTE antenna. The fabrication and measurements of the PAFMSTE antenna are introduced. The proposed antenna enable radio positioning via Angle of Arrival (AOA) information collected from nearby devices. Then, the Cramér-Rao Bound (CRB) is presented for AOA estimation using identically and equally spaced antenna elements. The CRB depends on the directivity, where the maximum values of CRB are 1.35 × 10-3 and 8 × 10-3 at HPBW of 60° and 90°, respectively.

开关磁阻电机霍尔位置信号的故障诊断方法

开关磁阻电机(SRM)驱动系统的可靠运行,需要位置传感器提供可靠的位置信号。因此针对霍尔位置传感器时常故障影响电机正常工作的问题,研究一种有效的位置信号诊断方法对于提高系统工作可靠性是有重要意义的。本文提出了一种时间阈值与状态预测相结合的故障诊断方法。首先分析了位置传感器故障的类型和发生位置;其次对所提出的基于时间阈值结合状态预测的方法作了理论分析,该方法将3个位置信号组合的实际状态值与预测状态值作实时比对,结合状态值转换时间进行阈值约束从而检测出各种故障并达到快速准确的效果;最后,为了验证所提方法的有效性,以三相12/8结构电机作为研究对象,对该方法进行了实验验证。实验结果证明了该方法在故障检测中的可行性和有效性。另外,该方法无需复杂的计算和额外硬件即可实现,可推广到无刷直流电机(BLDC)等驱动系统使用。

电网电压三相不平衡时FMSS正负序电流补偿型VSG控制

柔性多状态开关(FMSS)是一种取代传统联络开关应用于现代配电网的新型电力电子设备,能够优化现代配电网分布式电源的消纳和调控。和传统控制算法相比,采用VSG控制的FMSS不受弱电网环境下锁相环性能恶化的影响,在低电网强度下能够向电网提供频率支撑,从而增强系统的稳定性。FMSS作为接入配电网的装置,当电网电压发生三相不平衡现象时,传统VSG控制下的FMSS输出电流、功率会发生明显的波动,并网点的效率会大大降低。针对此问题,以模块化多电平变流器(MMC)结构为基础,在VSG控制策略的基础上引入正负序电流补偿,分别实现不平衡电网下FMSS输出电流、有功功率及无功功率的稳定。最后,通过Matlab/Simulink搭建四端FMSS模型,利用仿真验证所提控制策略的有效性。

含实时电流补偿的开关磁阻式机电作动器自适应PI控制

针对传统控制算法难以克服开关磁阻电机的非线性并有效抑制转向叶片的负载扰动,因而无法对开关磁阻式机电作动器进行快速高精度位置跟踪控制的问题,提出了一种含实时电流补偿的自适应PI控制器。首先,通过负载观测器对作用于转向叶片上的空气动力负载进行实时估算,进而转化为电流环的实时补偿电流来抑制负载扰动的影响;然后,基于开关磁阻电机的转矩电流特性拟合曲线与实时电流反馈值对转速环PI参数进行自适应最优调节,从而削弱了开关磁阻电机的非线性,增强了机电作动器的转速调节性能;最后,通过引入位置前馈环节,有效提高了机电作动器的响应速度和位置跟踪精度。仿真和实验结果表明:相较于传统PI控制器、自适应PI控制器和含前馈环节的自适应PI控制器,所提控制器将开关磁阻式机电作动器的响应速度分别提高了49.3%、44.4%和30%,位置跟踪精度分别提高了54.8%、49.2%和2.9%,从而使得机电作动器具备更强的位置跟踪性能。

基于北斗短报文的低功耗定位系统的设计

为解决传统定位系统功率损耗大,无法在脱机状态下长时间工作的问题,设计了一款基于硬件低功耗和软件“正常工作-休眠工作”双模式循环的定位系统。在硬件部分,该系统选用低功耗单片机STM32L431控制GPS定位模块CNS35和北斗短报文模块TM0558,并对供电电路实时采集。在软件部分,加入了“休眠工作”模式,实现与“正常工作”模式的循环切换。结果表明:该低功耗定位系统可实现定位误差低于2.5 m、通信成功率≥85%、双SIM卡切换等基本功能;且在单次循环为4 min的前提下,“正常工作2 min-休眠工作2 min”的工作方式将能量损耗降低至“正常工作4 min”方式的64.7%,续航时间延长了11.16 h。

正极性操作冲击电压下含悬浮导体长空气间隙放电发展过程

带电作业组合间隙是典型的含悬浮导体长空气间隙,含悬浮导体长空气间隙放电机理研究对提升带电作业安全性具有重要意义。为此搭建了棒-棒-板含悬浮导体长空气间隙放电观测平台,开展了悬浮导体位于不同位置的间隙放电观测试验,获得了施加电压、高电位放电电流以及放电光学图像等数据,研究了间隙的放电发展过程。研究结果表明,含悬浮导体长空气间隙这2个子间隙的放电会同时进行并相互影响,子间隙1放电主要由下行先导-流注体系和上行流注组成,子间隙2放电主要由先导-流注体系组成;悬浮导体位置会影响放电发展各阶段的起始时刻和放电发展时间;悬浮导体在任意位置时,放电从子间隙1起始,子间隙2中放电在子间隙1击穿前起始,子间隙2击穿不早于子间隙1击穿;子间隙1流注-先导转化所需临界电荷为0.26μC,与长空气间隙相似;预放电电流幅值、先导发展速度等放电发展特征与长空气间隙存在差异。

正负极性伪火花开关初步研究

介绍一种正负极性工作、无需热丝供电配套的伪火花开关,其触发方式可以采用电触发、空间激光触发以及光纤传输激光能量触发。在电触发模式下开关技术指标达到工作电压±60 kV、脉冲电流16.2 kA以及抖动7 ns;空间光触发模式下,开关抖动3 ns(1 mJ/532 nm),最低触发激光能量0.15 mJ;光纤传输激光能量触发工况下(光纤入射端能量7 mJ/出射端5 mJ/532 nm),开关抖动技术指标达到3 ns。

A Position and Torque Switching Control Method for Robot Collision Safety

With the increasing number of human-robot interaction applications, robot control characteristics and their effects on safety as well as performance should be taken account into the robot control system. In this paper, a position and torque switching con- trol method was proposed to improve the robot safety and performance, when robots and humans work in the same space. The switch- ing control method includes two modes, the position control mode using a proportion-integral （PI） algorithm, and the torque control mode using sliding mode control （SMC） algorithm for eliminating swing. Under the normal condition, the robot works in position con- trol mode for trajectory tracking with quick response. Once the robot and human collide, the robot will switch to torque control mode immediately, and the impact force will be restricted within a safe range. When the robot and human detach, the robot will resume to po- sition control mode automatically. Moreover, for a better performance, the joint torque is detected fl＇om direct-current （DC） motor＇s cur- rent rather than the torque sensor. The experiment results show that the proposed approach is effective and feasible.

直线旋转开关磁阻电机的轴向速度控制与快速轴向定位

目前直线旋转开关磁阻电机(Linear-rotary switched reluctance motor,LRSRM)只可实现轴向定位控制,两自由度运动方式较为单一。为提高LRSRM轴向控制性能,本文提出了一种轴向速度控制方法,通过线性位置/速度观测器协调控制转子的轴向位移和轴向速度,由转矩与轴向力的数学模型解算出转矩及轴向力绕组的给定电流,再将其分配到对应的绕组导通区间,分别进行电流滞环控制。该方法可以有效调节转子在旋转过程中的轴向定位速度。仿真和实验验证了所提方法的控制效果。

GIS三工位开关典型机械缺陷的特征量差异分析及辨识方法

近年来气体绝缘金属封闭开关(gas insulated switchgear,GIS)三工位开关行程不到位机械缺陷导致的设备运行故障案例频发,为提升GIS三工位开关行程不到位机械缺陷检测及运维水平,首先采用126kV全真型三工位开关试验平台设置机构卡涩、传动失耦和电机堵转三种典型机械缺陷,试验获得正常状态和3种典型机械缺陷情况下三工位开关分合闸动作过程中的电机电流、角位移行程和振动信号;然后,开展3种典型缺陷情况下“电流-机械”特征参量的提取及差异分析;最后,采用随机森林算法研究构建GIS三工位开关典型机械缺陷诊断模型,并验证其有效性。结果表明:单一的电机电流、角位移行程或振动信号图谱特性无法有效区分不同类型的机械缺陷,而采用“电流-机械”融合特征参量对3种典型机械缺陷的区分效果显著,基于“电流-机械”融合特征参量构建的GIS三工位开关机械缺陷随机森林诊断模型实现了对机构卡涩、传动失耦和电机堵转3种机械缺陷可靠诊断,为工程实际提升GIS三工位开关安全运行水平提供了技术参考。