Double Position Servo Synchronous Drive System Based on Cross-Coupling Integrated Feedforward Control for Broacher

Synchronization errors directly deteriorate the machining accuracy of metal parts and the existed method cannot keep high synchronization precision because of external disturbances. A new double position servo synchronous driving scheme based on semi-closed-loop cross- coupling integrated feedforward control is proposed. The scheme comprises a position error cross-coupling feedfor-ward control and a load torque identification with feed- forward control. A digital integrated simulation system for the dual servo synchronous drive system is established. Using a 20 t servo broacher, performance analysis of the scheme is conducted based on this simulation system and the simulation results show that systems with traditional parallel or single control have problems when the work- table works with an unbalanced load. However, the system with proposed scheme shows good synchronous perfor- mance and positional accuracy. Broaching tests are performed and the experimental results show that the maximum dual axis synchronization error of the system is only 8μm during acceleration and deceleration processes and the error between the actual running position and the given position is almost zero. A double position servo synchronous driving scheme is presented based on crosscoupled integrated feedforward compensation control, which can improve the synchronization precision.

Integrated construction technology for natural gas gravity drive and underground gas storage

Based on the mechanisms of gravity displacement,miscibility,viscosity reduction,and imbibition in natural gas flooding,an integrated reservoir construction technology of oil displacement and underground gas storage(UGS)is proposed.This paper systemically describes the technical connotation,site selection principle and optimization process of operation parameters of the gas storage,and advantages of this technology.By making full use of the gravity displacement,miscibility,viscosity reduction,and imbibition features of natural gas flooding,the natural gas can be injected into oil reservoir to enhance oil recovery and build strategic gas storage at the same time,realizing the win-win situation of oil production and natural gas peak shaving.Compared with the gas reservoir storage,the integrated construction technology of gas storage has two profit models:increasing crude oil production and gas storage transfer fee,so it has better economic benefit.At the same time,in this kind of gas storage,gas is injected at high pressure in the initial stage of its construction,gas is injected and produced in small volume in the initial operation stage,and then in large volume in the middle and late operation stage.In this way,the gas storage wouldn’t have drastic changes in stress periodically,overcoming the shortcomings of large stress variations of gas reservoir storage during injection-production cycle due to large gas injection and production volume.The keys of this technology are site selection and evaluation of oil reservoir,and optimization of gravity displacement,displacement pressure,and gas storage operation parameters,etc.The pilot test shows that the technology has achieved initial success,which is a new idea for the rapid development of UGS construction in China.

Dynamics of mechanical system for electromechanical integrated toroidal drive under electric disturbance

Based on electromagnetics and mechanics, electromechanical coupled dynamic equations for the drive were developed. Using method of perturbation, free vibrations of the mechanical system under electric disturbance were investigated. The forced responses of the mechanical system to mechanical excitation under electric disturbance were also presented. It is known that for the system with electric disturbance, as time grows, beat occurs. When electric disturbing frequency is near to the natural frequencies of the mechanical system or their integer multiple, resonance vibrations occur. The forced responses of the mechanical system to mechanical excitation under electric disturbance are compound vibrations decided by mechanical excitation, electric disturbance and parameters of the system. The coupled resonance vibration caused by electric disturbance and mechanical excitation was discussed as well. The conditions under which above coupled resonance occurs were presented. The results show that when the difference of the excitation frequency and the perturbation frequency is equal to some order of natural frequency, coupled resonance vibrations occur.

High-Mobility P-Type MOSFETs with Integrated Strained-Si_(0.73)Ge_(0.27) Channels and High-κ/Metal Gates

Strained-Si0.73Ge0.27 channels are successfully integrated with high-R/metal gates in p-type metai-oxide- semi- conductor field effect transistors （pMOSFETs） using the replacement post-gate process. A silicon cap and oxide inter layers are inserted between Si0.73Ge0.27 and high-κ dielectric to improve the interface. The fab- ricated Si0.73Ge0.27 pMOSFETs with gate length of 3Onto exhibit good performance with high drive current （~428μA/μm at VDD = 1 V） and suppressed short-channel effects （DIBL^77mV/V and SS^90mV/decade）. It is found that the enhancement of effective hole mobility is up to 200% in long-gate-length Si0.73Ge0.27-channel pMOSFETs compared with the corresponding silicon transistors. The improvement of device performance is reduced due to strain relaxation as the gate length decreases, while 26% increase of the drive current is still obtained for 30-nm-gate-length Si0.73Ge0.27 devices.

Maxim Integrated与NVIDIA通力合作，打造面向汽车信息娱乐和辅助驾驶系统的DRIVE CX和PX平台

北京，2015年7月30日。技术领先的高性能模拟集成供应商Maxim Integrated Products，Inc．（NASDAQ：MXIM）与NVIDIA通力合作，为NVIDIA汽车信息娱乐和高级辅助驾驶系统（ADAS）DKIVECX（驾驶室）和PX（辅助驾驶）平台提供模拟电路。

Realization of an 850V High Voltage Half Bridge Gate Drive IC with a New NFFP HVI Structure

A NFFP HVI structure which implements high breakdown voltage without using additional FFP and process steps is proposed in this paper. An 850 V high voltage half bridge gate drive IC with the NFFP HVI structure is experimentally realized using a thin epitaxial BCD process. Compared with the MFFP HVI structure, the proposed NFFP HVI structure shows simpler process and lower cost. The high side offset voltage in the half bridge gate drive IC with the NFFP HVI structure is almost as same as that with the self-shielding structure.

Analysis for Effects of Temperature Rise of PV Modules upon Driving Distance of Vehicle Integrated Photovoltaic Electric Vehicles

The development of vehicle integrated photovoltaics-powered electric vehicles (VIPV-EV) significantly reduces CO2 emissions from the transport sector to realize a decarbonized society. Although long-distance driving of VIPV-EV without electricity charging is expected in sunny regions, driving distance of VIPV-EV is affected by climate conditions such as solar irradiation and temperature rise of PV modules. In this paper, detailed analytical results for effects of climate conditions such as solar irradiation and temperature rise of PV modules upon driving distance of the VIPV-EV were presented by using test data for Toyota Prius and Nissan Van demonstration cars installed with high-efficiency InGaP/GaAs/InGaAs 3-junction solar cell modules with a module efficiency of more than 30%. The temperature rise of some PV modules studied in this study was shown to be expressed by some coefficients related to solar irradiation, wind speed and radiative cooling. The potential of VIPV-EV to be deployed in 10 major cities was also analyzed. Although sunshine cities such as Phoenix show the high reduction ratio of driving range with 17% due to temperature rise of VIPV modules, populous cities such as Tokyo show low reduction ratio of 9%. It was also shown in this paper that the difference between the driving distance of VIPV-EV driving in the morning and the afternoon is due to PV modules’ radiative cooling. In addition, the importance of heat dissipation of PV modules and the development of high-efficiency PV modules with better temperature coefficients was suggested in order to expand driving range of VIPV-EV. The effects of air-conditioner usage and partial shading in addition to the effects of temperature rise of VIPV modules were suggested as the other power losses of VIPV-EV.

新一代高韧性直流输电技术(二):高倍载模块化换向式换流器

针对高韧性直流输电技术对高倍载、高经济性直流换流器的需求,提出一种高倍载模块化换向式换流器(high-overload modular commutated converter,MCC)。首先,对MCC的拓扑构造和运行原理进行详细分析,指出其器件软开关特性、桥臂能量脉动优化和高倍载潜力;针对MCC的宽范围电压变比调节、串联模块电压均衡控制、架空线应用中的直流故障自清除等关键问题,给出解决方案;以±500 kV/2000 MW直流输电系统为例,分析MCC的元件用量、体积、效率、成本等技术特性,并与常规模块化多电平IGBT换流器进行综合对比;最后,研制基于IGCT-Plus器件的±15 kV/60 MVA MCC产品,开展综合性测试验证。结果表明,提出的MCC有望将现有换流器技术方案的体积、成本、损耗率分别减小达50%,在电能变换与传输中具有广阔的应用前景。

可控关断逆阻型IGCT换流阀研制

基于大功率晶闸管构成的电流源型换流器在HVDC工程中得到广泛应用,由于晶闸管的固有关断特性,当交流系统电压跌落时会引发换相失败问题,这将导致直流功率波动、甚至直流闭锁,威胁电网安全稳定运行。为了解决换相失败问题,首先基于逆阻型集成门极换流晶闸管(RB-IGCT)构建了新型换流器,提出了这种换流器的两种运行模式,设计了可控关断RB-IGCT换流器控制系统,并基于所设计的控制系统提出了换流器换相工作时序。其次采用6英寸RB-IGCT设计了换流阀,并提出了IGCT驱动单元的设计方案。最后搭建了换流阀运行试验系统,完成了RB-IGCT换流阀样机研制和验证,通过试验验证了换流阀设计的合理性。所提成果可为后续RB-IGCT在HVDC工程中的应用提供有力支撑。

文化与科技深度融合语境下档案文献遗产“活化”的驱动因素、困境与对策

文化与科技的深度融合正由重要性认知向紧迫性战略转变,因此,从更高层面文化与科技的深度融合维度来思考档案文献遗产的“活化”变得尤为关键。档案文献遗产“活化”包含政府、技术、场景和市场四个主要驱动因素。然而,在实际进程中,档案文献遗产与科技的“双轮驱动”存在偏颇性,同时,科技固有矛盾也不断侵入并引发新问题。据此,提出激活驱动因素的关键引擎作用,深化“互促共进”有效途径和释放科技内在“向善”潜力的应对之策。

中国特色学徒制视域下课程思政探索与实践——以新能源汽车驱动电机及控制技术课程为例

文章以新能源汽车驱动电机及控制技术课程为例,探索中国特色学徒制背景下的课程思政改革。以驱动电机产业需求为导向,精心组建产业导师、专业主任、教学名师和骨干教师为核心的课程团队,开发出与产业新技术、新工艺、新材料、新设备相对接的典型教学项目。从课程目标、教学内容、教学实施等层面开展课程思政教育,将家国情怀、科技创新、工匠精神、职业素养等思政元素自然地融入到教学过程之中,成功培养出一批德技并修的新能源汽车驱动电机产业应用型人才,为推动新能源汽车产业的发展贡献了教育力量,也为其他专业课程在新时代背景下的课程思政改革提供了有益的借鉴和参考。

New digital drive phase control for improving bias stability of silicon MEMS gyroscope

In order to improve the bias stability of the micro-electro mechanical system（MEMS） gyroscope and reduce the impact on the bias from environmental temperature,a digital signal processing method is described for improving the accuracy of the drive phase in the gyroscope drive mode.Through the principle of bias signal generation,it can be concluded that the deviation of the drive phase is the main factor affecting the bias stability.To fulfill the purpose of precise drive phase control,a digital signal processing circuit based on the field-programmable gate array（FPGA） with the phase-lock closed-loop control method is described and a demodulation method for phase error suppression is given.Compared with the analog circuit,the bias drift is largely reduced in the new digital circuit and the bias stability is improved from 60 to 19 °/h.The new digital control method can greatly increase the drive phase accuracy,and thus improve the bias stability.

面向MMC应用的大功率IGCT器件加速老化试验拓扑研究

集成门极换流晶闸管(integrated gate commutated thyristor, IGCT)具有阻断电压高、通流能力强等特点,在柔性直流输电等领域具有广阔的应用潜力,但其在高电压、大通流应力下的可靠性问题,成为限制应用的潜在因素,如何针对不同工况开展加速老化等效测试成为开展可靠性研究的关键瓶颈。文中以模块化多电平换流器(modular multilevel converter,MMC)工况为代表,针对IGCT器件可靠性等效测试难题开展研究。首先分析MMC工况下IGCT器件的暂态电气应力和长期电热应力,分别采用TCAD仿真软件与平均值等效计算模型定量获得IGCT器件在实际工况下的应力大小;其次,基于应力分析结果,提出一种三半桥式两级电流应力加速老化试验拓扑,设计并搭建2 500 V/4 000 A/150 Hz参数的IGCT加速老化试验平台;最后,开展约100 h高压、大电流老化运行试验,验证平台具备长时运行的能力,且等效测试应力达到设计要求。所提出的等效拓扑及其构建方法,不仅解决了MMC工况下IGCT器件的加速老化测试问题,对其他交直流变换工况、其他类型功率半导体亦有很好的参考价值。

一种新型IGCT门极驱动单元设计

门极驱动单元(GU)是集成门极晶闸管(IGCT)的重要组成部分,GU需具备主驱动控制(强触发开通、维持导通、门极换流关断)、状态检测、逻辑监测等功能。为了满足大功率等级IGCT器件开关性能的要求以及电网特殊应用工况,本文优化门极电流续流拓扑、改进铜皮硬压搭接的分离式方案、优化关断电容组合,提出了一种具备快速响应、黑启动、可拆卸、高可靠性的新型IGCT门极驱动单元。本文搭建了开通能力测试平台、脉冲测试平台和功率对推测试平台,对所提GU的高性能和可靠性进行了验证,研究结果可为非对称IGCT(AS-IGCT)在后续的柔性直流电网中的工程应用提供参考。

驱控一体的旋拧式果实采摘执行器设计与试验

针对果园智能化采收作业需要,设计了支持总线扩展的驱控一体旋拧采摘末端执行器,旨在为多臂并行采摘机器人研发提供支撑。在对标准苹果树果实物理形态统计分析基础上,结合人工采摘方法,提出了“吸附-夹持-旋拧”的采摘机械操作方法,并设计了基于双舵机驱动的紧凑型采摘执行机构,对其吸盘、夹持和旋拧电机的关键参数进行了优化设计。面向多执行并行采摘需要,设计了基于CANopen通讯的采摘操作驱动器,实现了多执行器的总线扩展。通过现场试验对执行器作业性能进行了测试,结果表明:果实大小在60~100 mm之间,采摘成功率可达到90%,吸盘最优停留时间为1.00 s,吸盘最优接近距离为1.0 mm,最优旋拧角度为360°。

图腾柱式IGBT栅极驱动电路设计

由晶体管BJT构成的图腾柱式栅极驱动电路在单相交错式PFC中被大量应用,本文分析了IGBT栅极特性和栅极驱动电路结构,分别推导了栅极最大电流、 BJT基极电流以及驱动功率的计算方法,全面地得出了IGBT栅极驱动电路关键器件的参数选型和注意事项。

综合运动约束和RANSAC的视觉前端完好性增强与误差建模

卫星/惯性/视觉多源导航因其精度和鲁棒性的优点,逐渐成为自动驾驶等智慧交通领域中的主流导航方案。视觉信息是这一多源导航系统中的关键输入之一。然而,视觉信息存在误差模型随场景变化显著、故障率高等问题。为保障导航定位的可靠性,增强视觉导航信息的完好性,提出了基于运动约束的视觉前端故障检测器,并与随机采样一致性(Random Sample Consensus,RANSAC)结合来降低视觉信息故障率。同时,基于误差包络理论确定保守的视觉前端误差模型。实验结果表明,该视觉前端完好性增强方法能够明显降低视觉特征点的误差标准差,相比于仅使用RANSAC的方法降低约70%。更重要的是,结合运动约束与RANSAC方法能够使得误差模型对场景不敏感。此项研究对于增强视觉参与的多源导航完好性具有重要意义。

掘锚一体机快速掘进控制方法设计

为了提升掘锚一体机在复杂矿井环境中的快速掘进能力,本文通过介绍一个具体项目实例,包括工程概况与机组技术参数,详细分析了掘锚一体机快速掘进技术的关键环节。构建了水平方向摆动运动的数学模型,探讨了掘进过程中矿井冲击地压的计算方法,并设计了掘锚一体机的远程控制系统。进一步,提出了“S”形掘进路径规划策略以促进快速掘进。研究结果表明,该控制方法显著提高了掘锚一体机的掘进效率与安全性,为冲击地压矿井的快速掘进提供了有力支持。

Effect of Metal Contamination on Characteristics of Ultra-Thin Gate Oxide

The purpose of this work relates to study on the characteristics of ultra thin gate oxide (2 5nm thickness) and the effect of metal Al,Zr,and Ta contamination on GOI.The controlled metallic contamination experiments are carried out by depositing a few ppm contaminated metal and low pH solutions on the wafers.The maximum metal surface concentration is controlled at about 10 12 cm -2 level in order to simulate metal contamination during ultra clean processing.A ramped current stress for intrinsic charge to breakdown measurements with gate injection mode is used to examine the characteristics of these ultra thin gate oxides and the effect of metal contamination on GOI.It is the first time to investigate the influence of metal Zr and Ta contamination on 2 5nm ultra thin gate oxide.It is demonstrated that there is little effect of Al contamination on GOI,while Zr contamination is the most detrimental to GOI,and early breakdown has happened to wafers contaminated by Ta.