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空心罗氏线圈是测量kA级脉冲大电流的常用传感器。随着脉冲电流发生器的小型化发展,集成于脉冲电流发生器的测量线圈也必须进行小型化设计。本文设计了小截面柔性罗氏线圈。在考虑了由线圈绕线引起的漏磁影响后,本文推导了罗氏线圈的输出特性,修正了传统罗氏线圈电磁参数的计算公式。在给定线圈外尺寸的限制条件下,本文推导了罗氏线圈的互感随线圈内径、绕线直径变化的关系式,并据此推出具有最大互感时的设计值。经样品试制与实验测试,罗氏线圈的输出值与理论分析吻合。将该样品用于脉冲电源的脉冲大电流测量,并与标准的Pearson电流探头做对比,比照结果说明研制的罗氏线圈测量准确。 相似文献
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分析雷电流监测装置的同轴分流器的电压电流方法、线圈的互感器方法和积分方法、雷电流参数的响应特性。通过磁芯线圈测量雷电流必须防止磁饱和,体积较大。小体积的磁芯线圈容易饱和,不适宜测量雷电流,空芯线圈性能受安装环境影响大。 相似文献
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着重介绍用内积分流变线圈法测量脉冲大电流的基本原理、变流线圈及测量回路的参数选择与设计原则以及测量系统方波响应及标定方法。 相似文献
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设计了一种断路器分合闸线圈状态检测及保护系统,该系统通过监测及记录每次断路器分合的状态,在跳合闸过程中,有效保护由于种种原因导致跳合闸线圈拒动时的跳合闸线圈。通过霍尔传感器测量分合闸线圈回路的直流电流,根据采集到的直流电流大小计算分合闸线圈的发热量,设定达到线圈发热的极限值,通过电力电子元件器IGBT和继电器组合的回路来分开分合闸线圈回路,达到保护分合闸线圈功能。实际应用表明,该系统运行稳定,较好地实现了断路器分合闸线圈状态检测及保护。 相似文献
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本文讲述了一种具有校正功能的罗氏线圈的设计方法,利用复式积分原理,采用电压跟随器、有源积分电路、同相放大电路、加法器等有源器件及其反馈环节实现对罗氏线圈的输出波形进行校正、拓展测量电流频带宽度的功能。该方法已在实际生产中应用,效果显著,能准确有效的测量中频高频大电流,而且结构简单,易于加工。 相似文献
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采用连续波电光检测法,对GaAs/GaAlAs双异质结激光器列阵有源区进行定点测量,实验结果反映了发光区内及发光区外电场随电流变化的不同规律。文中对实验结果给出了合理解释。 相似文献
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We highlight some physical phenomena occurring in pulsed eddy current testing, through the modeling of the response of a voltage
driven pulsed eddy current sensor for the characterization of the thickness and conductivity of a metallic conductive plate.
We use the finite element time domain method coupled to the electric circuit equation in the eddy current sensor which consists
of an air cored coil. The characterization parameters are obtained from the current variation in the coil. The effects of
the thickness and conductivity are clearly distinguished by considering three metallic plates of different conductivities.
Time and frequency approaches are considered. We show that the reconstitution of the coil response signal from its Fourier
series expansion leads to a loss of important features of the latter, limiting thus the characterization parameters, since
this reconstitution does not take account of the sub-transient phenomena, i.e., the time of diffusion of the electromagnetic
field in the conductive plate. The numerical results are supported by measurements. 相似文献
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自触发脉冲激光测距飞行时间测量研究 总被引:1,自引:0,他引:1
提出一种新型脉冲激光测距方法——自触发脉冲飞行时间激光测距方法。运用该方法有效解决了传统脉冲激光测距法中存在的提高测量精度和缩短测量时间两者之间的矛盾。对该方法及本质特点进行了详细描述和理论分析,并给出用于描述该方法的基本方程。其飞行时间测量系统的设计很大程度上决定了自触发脉冲激光测距的测量精度和测量速度。设计并实现了基于CPLD的自触发脉冲激光测距飞行时间测量系统。CPLD的使用提高了测量精度,并且结构简单,体积小,可靠性高,非常适合高性能便携式的激光测距仪。 相似文献
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CPLD在自触发脉中激光测距飞行时间测量中的应用 总被引:1,自引:0,他引:1
自触发脉冲激光测距是一种新型的脉冲激光测距方法,该方法解决了传统脉冲激光测距测量精度与测量速度之间的矛盾.其飞行时间测量系统的设计很大程度上决定了自触发脉冲激光测距的测量精度和测量速度.设计并实现了基于CPLD的自触发脉冲激光测距的飞行时间测量系统.CPLD的使用提高了激光测距的精度,并且系统结构简单,体积小,可靠性高,非常适合高性能手持式脉冲激光测距仪.对自触发脉冲激光测距进行了实验研究,在20 m的测量范围内,获得了±0.98 mm的测距精度. 相似文献
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A system for measuring output characteristics of FET's using nanosecond pulses, instead of dc voltage and current measurement, is described. The measurement system is used to obtain the I-V characteristics of silicon-on-insulator (SOI) FET's without the degradation resulting from self heating. Use of the technique to study partially depleted SOI FET's with floating bodies shows that under pulsed conditions, their output curves have a history dependence. The physical mechanisms responsible for the history dependence are explained. Further understanding of the physical mechanisms is given by examination of single-shot pulse measurements. The role of transient and time-dependent phenomena in determining I-V curves is elucidated 相似文献
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《Applied Superconductivity》1999,6(6):247-257
A new design concept of the axisymmetric magnet system generating the very high pulsed magnetic field which is superimposed on the bias magnetic field of the superconducting magnet is presented. The pulsed magnet consists of two coaxial coils which are wound in opposite directions. The geometry of both pulsed coils, i.e. the working (inner) one and the compensating (outer) one is designed in such a way that the mutual coupling between the small pulsed magnet and the outer superconducting magnet is practically zero. This configuration prevents the rise of the high induced voltage on the current leads of the superconducting magnet when the pulsed magnet is being energised, hence resulting naturally in protection of the system (superconducting magnet and the current source) against possible damage. Further, it is predicted that the stray field of the pulsed magnet, which gives rise e.g. to the eddy currents in the winding of the superconducting magnet, is considerably decreased. The simple theory enabling the design of the geometry of the compensating pulsed coil is derived. The advantages of this new concept are demonstrated on the results of the theoretical analysis using, as an example, one of the pulsed coils that were designed and fabricated in the Clarendon Laboratory, in connection with the Oxford Instrument superconducting magnet (Clarendon hybrid outer) which can generate a steady magnetic field up to 10 T in a room temperature working space with a diameter of 240 mm. 相似文献
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在分析无线通信环境中脉冲干扰特征及其对无线通信影响的基础上,提出利用修正周期图功率谱密度和NP定理对周期性脉冲干扰进行干扰检测的策略与脉冲周期及占空比等参数测量的方法。在给定虚警率指标下,推导并计算了周期性脉冲干扰检测的概率,并通过实验仿真验证了采用本文所提策略检测周期性脉冲干扰的有效性和准确性。 相似文献
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研究了线圈间距、匝数、个数以及不锈钢套筒对脉冲磁体产生磁场的影响规律。在储能电容和电压不变的前提下,研究结果表明:增加线圈间距会导致磁感应强度降低,磁力线包络增大,但总电流达到峰值时刻减小;增加线圈匝数,峰值电流明显减小,会降低磁感应强度,但有利于抑制磁力线包络;增加并联线圈个数,有利于产生较长的均匀区,但是在供能一定的条件下,磁场强度有所降低,同时总电流达到峰值时刻减小。总体来看,在一定均匀区长度的设计要求下,减少单个线圈匝数,增加并联线圈个数,能够得到磁感应强度更大、均匀性更好的磁场,但要考虑线圈承载电流的能力。另外,不对称的阴阳极金属结构会导致磁场不对称分布,且磁感应强度达到峰值时刻要晚于总电流达到峰值的时刻。 相似文献
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The effects of traps in GaAs MESFETs are studied using a pulsed gate measurement system. The devices are pulsed into the active region for a short period (typically 1 μs) and are held in the cutoff region for the rest of a 1-ms period. While the devices are on, the drain current is sampled and a series of pulsed gate I -V curves are obtained. The drain current obtained under the pulsed gate conditions for a given V GS and V DS gives a better representation of the instantaneous current for a corresponding V gs and V ds in the microwave cycle because of the effects of traps. The static and pulsed gate curves were used in a nonlinear time-domain model to predict harmonic current. The results showed that analysis using pulsed gate curves yielded better predictions of harmonic distortion than analysis based on conventional state I -V curves under large-signal conditions 相似文献