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与传统的频率变换器相比,矩阵变换器能够实现功率的双向流动,驱动电机四象限运行,输入端功率因数可调节为1,输出电压幅值、相位和频率可独立调节等优点。由于矩阵变换器的一般控制算法为开环控制,使当输入存在干扰时,输出电压的质量就会受到影响。采用一种基于电压滞环控制的闭环控制策略,对电压进行闭环控制,并在Matlab环境下建立仿真模型,仿真结果表明该控制算法是可行和有效的。 相似文献
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蔡顺燕 《四川教育学院学报》2014,(11):110-113
设计了一种输入电压为5.5V~25V,输出电压为5V的直流稳压电源及其漏电保护装置系统.直流稳压电源模块采用达林顿管TIP42、OP07运算放大器及三极管构成一个深度负反馈稳压电路.输出电压经ADS1286转换为数字量后送入单片机采样输出电压,经霍尔电流传感器CSM002A、跟随器OP07后,送入ADS1286,转换为数字量后送入单片机采样负载电流.由软件程序计算功率,并在液晶上显示.通过采样负载电流与总电流的差值实现漏电检测,并进行漏电保护.经测试,系统电压调整率Su≤1%,负载调整率SL≤1%,5.5V ~ 25V输入,输出为5±0.05V. 相似文献
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A novel cement-based piezoelectric sensor wasdeveloped recently[1—3]. It can be used in civil engi-neering structure for measuring the dynamic load in-duced by wind, earthquake, etc. The sensor wasmade by jointing two cement paste cubes with a piezo-electric ceramic plate using encapsulation material de-veloped specially for the sensor[4]. When calibratedby Material Test System(MTS), the sensor showed agood frequency independency and linear relationshipbetween input loading and output volta… 相似文献
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A displacement sensor based on the fiber Fabry-Perot (F-P) cavity was proposed in this paper. Theoretical and experimental analyses were presented. Displacement resolution was demonstrated by spectrum-domain experiments to obtain the dynamic range of the F-P sensor, and a piezoelectric crystal unit (PZT) was used as the driver. The output signal was modulated by a piezoelectric ceramic ring and demodulated by a phase-locked oscillator. The experimental results show that the displacement resolution of the F-P sensor is less than 5 nm and the dynamic range is more than 100 μm. As acceleration is the second-order differential of displacement, an accelerometer model was proposed using the finite element method (FEM) nd ANSYS software. 相似文献
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该文提出了一种输入电压22V~60V,输出电压12V、输出电流1A的电源适配器设计方案,同时可通过远程上位机控制其工作状态.该系统主要由输入部分、控制部分和输出部分组成.STC89C2051作为主控单片机,功率输出部分采用开关电源,其内部资源集成RS232通信协议,可以实现远程数据发送和接收控制命令.经过实验测试,完全达到了设计的要求. 相似文献
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针对很多无线供电应用场合需要保持输出电压恒定的需求,提出了一种高频逆变器前动态调压的恒压输出控制方法。以LCL-S型感应耦合电能传输系统为研究对象,通过阻抗分析法建模,发现通过元器件的参数配置,可使系统输入阻抗为纯阻性,减少无功分量,同时逆变器开关管实现了零电流开通与关断,但此时系统输出电压并不恒定。针对分析结果提出基于模糊自适应PI控制算法的逆变前动态调压控制的恒压输出控制方案,最后搭建了仿真实验平台和实验样机证明了分析结果的正确和控制方案的有效。 相似文献
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基于Jazz工艺,提出一种线性可控全集成Si Ge Bi CMOS驱动放大器(DRA),实现多种可调功率增益放大作用。电路采用全差分共射共基结构,通过调节CMOS电流镜偏置电路和Si Ge-HBT管尺寸以及3bit控制位,实现1d B步长的可控增益。仿真结果显示:在10μA的带隙基准电流源以及3.3V的电源电压下,DRA实现八种可调功率增益,其线性度指标即输出1d B压缩点OP1d B〉3d Bm,电路供电电流〈10m A,且电路输入输出匹配良好(S11与S22均小于-19d B)。 相似文献
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Yuan-feng DUAN Ru ZHANG Yang ZHAO Siu-wing OR Ke-qing FAN Zhi-feng TANG 《浙江大学学报(A卷英文版)》2011,12(12):895-901
Steel structures are widely used in railway infrastructures. Their stress state is the most important determinant of the safety
of these structures. The elasto-magnetic (EM) sensor is the most promising for stress monitoring of in-service steel structures.
Nevertheless, the necessity of magnetic excitation to saturation due to the use of a secondary coil for signal detection,
keeps from its engineering application. In this paper, a smart elasto-magneto-electric (EME) sensor using magneto-electric
(ME) sensing units to take the place of the secondary coil has been exploited for the first time. The ME sensing unit is made
of ME laminated composites, which has an ultrahigh ME voltage coefficient and can measure the magnetic induction simply and
precisely. Theoretical analysis and characterization experiments firstly conducted on the ME laminated composites showed that
the ME sensing units can be applied in the EM sensor for improved performance in stress monitoring. A tension test of a steel
bar was carried out to characterize our smart EME sensor and the results showed high accuracy and sensitivity. The present
smart EME sensor is a promising tool for stress monitoring of steel structures in railway and other civil infrastructures. 相似文献
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径向模式振动的压电变压器是由硬的压电材料建成,具有较高的机械品质因数Qm,它是沿厚度方向极化。首先根据压电变压器等效电路模型图建立压电变压器的动力学模型,根据各个负载电阻,测定的电压升压比,输出功率,效率方面的电性能,得出电压升压比与负载电阻成比例地增大,之后对不同厚度的压电变压器进行Comsol仿真,对比得出最优的压电变压器。后通过MATLAB仿真得出电阻最佳时,效率达到最大可以达到90%,升压比为1.5,对这些结果进行比较,从等效电路的分析计算,得出他们有很高的效率和稳定性,可以解决原有卫星推进器效率低、不稳定的状况。 相似文献
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A first order system model of fracture healing 总被引:1,自引:0,他引:1
INTRODUCTION Fracture healing is an important research subject in biomechanics. During the last years, many theories and simulation models have been proposed for de- veloping a comprehensive view of the mechanisms controlling bone morphogenesis. Pauwels (1960) was one of the first authors to propose a theory of tissue differentiation in response to local mechanical stress and strain. He assumed that deviatoric stresses com- prise the specific stimulus for the formation of fibrous connecti… 相似文献
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张鉴 《黄冈职业技术学院学报》2007,9(4):21-25
本文应用超磁致伸缩材料(GMM)构建FBG的电流传感探头,与ASE光源谱特性解调系统共同组成了交流电流测量系统,对50Hz的交流电流进行测量,并通过温度解调传感实验先对ASE光源谱特性解调进行了定标。通过实验标定ASE光源谱特性解调应变灵敏度系数,最终将交流电流形成的布拉格波长漂移量解调成交变的电压信号输出。该信号与输入电流信号相对应,并且包含了输入电流信号的幅值、频率和相位信息。从示波器测得的输入和输出信号的相似性表明,实验结果与理论分析是一致的,验证了ASE光源谱特性动态解调方法的可行性。 相似文献
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基于基波分析法( FHA)对LLC谐振变换器进行建模分析,并以此为依据提出一种简化的参数设计方法。该方法根据谐振电路的二端口模型得到归一化工作频率和电压增益的关系,按照规定输入输出的要求确定电压增益后得到谐振工作频率,进而可以得到谐振电路的特性阻抗和谐振腔元件参数。利用Saber软件仿真和硬件实验验证了该方法的有效性,表明所设计的变换器可实现开关管的零电压开通和整流二极管的零电流关断,能够降低开关损耗,提高装置效率。 相似文献
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基于网络的A参数,利用网络分析法分析了由OTA组成的4种组态负反馈放大器的闭环特性,结果表明:对OTA施加负反馈,闭环放大倍数,闭环输入、输出电阻的改变量,形式上仍为1 AF,这与由传统电压型运放构成的负反馈放大器结论一致。 相似文献
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利用有限元软件ABAQUS对纯钢框架试件、冷弯薄壁型钢组合墙体试件、钢框架-冷弯薄壁型钢组合墙体试件、覆双面OSB板的钢框架-冷弯薄壁型钢组合墙体试件进行水平低周往复荷载作用下研究,分析了试件的滞回曲线、骨架曲线、抗侧刚度、延性和耗能等。结果表明,钢框架与冷弯薄壁型钢组合墙体有明显的组合效应;冷弯薄壁型钢组合墙体能明显增强钢框架结构的承载力、刚度、延性和耗能能力;覆双面OSB板钢框架-冷弯薄壁型钢组合墙体结构抗震性能较不覆板的钢框架-冷弯薄壁型钢组合墙体结构抗震性能好。 相似文献
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简易数控直流稳压电源的设计 总被引:1,自引:0,他引:1
陈石龙 《宁德师专学报(自然科学版)》2010,22(1):59-61,66
随着时代的发展,数字电子技术已经普及到人们生活中的各个领域.本系统设计成一控制输出电压在5~9V且步进为0.5V的直流稳压电源,电路由数字控制部分、D/A转换部分、可调稳压部分组成.数字控制部分采用+/-按键来调整控制一可逆二进制计数器来预设电压值,二进制计数器输出输入到D/A转换器中,经过D/A转换后控制调整步进为0.5V,经测试,可输出稳定5~9V的稳定直流电源,步进0.5V,纹波小于50mV.同时预设一个复位按键来进行复位. 相似文献
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Fiber Bragg grating(FBG) is used as a wavelength reference device to calibrate the position of gas absorption peak in the intracavity absorption gas sensor(ICAGS) based on erbium-doped fiberring laser.This system can detect both the reflectance spectrum of FBGs and absorption spectrum of measured gas during a single wavelength sweeping process by linearly varying the driving voltage of optic filter.The voltages corresponding to center wavelength positions of four FBGs in the spectrum are determined through ... 相似文献
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王战备 《渭南师范学院学报》2013,(12):64-68
针对无线传感器网络能量供应瓶颈问题,设计实现了一种基于太阳能的无线传感器网络节点供电系统.该系统在实现基于太阳能的电池充电、电池保护等功能的同时,能够自动检测分析太阳电池板输出电压值,并可在其值达到设定值时,将系统供电源由充电电池切换为太阳能电池板,通过降压稳压处理后为节点提供所需的工作电源.测试结果表明:该供电系统输出电压3.3 V左右,平均偏差小于3%,能够为野外环境中的无线传感器网络节点提供持续稳定的电源供给. 相似文献
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LAU C.W.H. LIM C.W. LEUNG A.Y.T. 《浙江大学学报(A卷英文版)》2005,6(9):962-966
INTRODUCTION Piezoelectricity is an electromechanical phe- nomenon which couples elasticity and electricity through the existence of pressure induced electrical field or electric induced stress field. The piezoelectric materials are usually surface bonded in patches or fully embedded in the host structure, so that the structure becomes a laminated piezoelectric beam. Tzou and Gadre (1989), Lee (1990), Crawly and Lazarus (1991) developed laminated plate models incorporating the piezoelect… 相似文献