电流

Traditional instrument in harmonic measurement is the transformer with circularity form core coil, but it is influenced by direct current and saturated, so it could not be used to measure direct harmonic current.

基于Rogowski 线圈的光电直流谐波电流测量系统解决了传统谐波电流测量受直流分量影响的难题，是集光纤技术、电子技术、激光技术于一体的新型谐波电流互感器。

A novel compensating method is provided utilizing the stator currents decoupling and the linearization of the angle interval of current vectors.Based on the performance index of voltage utilization ratio, total harmonic distortion, switching loss and etc, various PWM methods have been introduced.

本文详细分析了逆变器输出的非线性特性及影响因素，重点对零电流夹断现象及其机理进行深入的研究，针对电流过零区间的非线性畸变提出了利用定子电流解耦以及电流矢量角度区间线性化的补偿方法。

AlN MSM devices were fabricated on AlN epitaxial thin film deposited on GaN/Sapphire substrates using helicon sputtering system at the low temperature of 300°C. The device characteristic was found to be improved by in situ metallization of Al electrodes. The extremely low dark current (1.39pA at 20V), the ideal factor (1.0125) and the Schottky barrier height (0.916eV) are superior compared to those of AlN MSM in the literature. When the device was illuminated by the 150W D2 lamp, the ratio of the induced photocurrent to dark current is more than 2 orders of magnitude. The illumination effect also shows the linear relationship between the radiation power and the photo current for the MSM devices, indicating the potential applicability for deep UV sensors.

氮化铝金属-半导体-金属光侦测器则是用In situ metallization制程，利用低温回旋溅镀法在氮化镓/蓝宝石基板上沉积之氮化铝，再直接溅镀金属铝作为指叉电极，比较目前文献制作出来的氮化铝MSM元件，可得到很好的元件金半接面之理想因子1.0125，算出萧特基能障高度为0.916eV，并有很低的暗电流为1.39 pA，提升了元件的特性，使用150 W氘灯入射，光暗电流差距可到两个order，且元件之光电流与入射光功率呈线性，显示所制作之氮化铝MSM元件，很适合针对深紫外光波段侦测。

The relations of inducing skin current of shielding layer, core voltage and core current with the environment field were obtained. The change of shield layer current wave with grounding state of external shield and core voltage with loading resistance was analyzed. According to the dependence of shield layer current oscillating frequency on electromagnetic wave propagation velocity, conception of transporting line of shield layer-ground with equivalent relative dielectric constant was presented. fited equation of equivalent relative dielectric constant with change of cable height was given.

试验得到九芯电缆屏蔽层感应电流、芯线感应电压、芯线感应电流以及环境场之间的关系；分析了皮电流波形随外皮接地状态的变化，芯电压随负载电阻的变化；基于皮电流振荡频率与电磁波传播速度的关系，提出了屏蔽层-大地"传输线"等效相对介电常数概念，给出了等效相对介电常数随电缆高度变化的拟合式；皮电流计算与测量结果在波形、振荡周期、衰减规律等方面有较好的一致性。

ABSTRACT Aiming at problems of trans-vector controller in a vehicle-carried induction motor such as variable rotor and stator resistance following motor temperature, and their inductance varying with flux saturation degrees. Firstly, CSI and VSI are introduced, for CSI, it can hold the advantages both FOC and DTC using stator flux directional, PI parameter and simulation are also introduced. Secondly, equations of IM in the synchronous rotary frame and its static counterpart, as figuring in the saturation condition of magnetic field, are dealt in this paper and the simulation results are presented. Thereafter, the parameter designing of PI trans-vector controller is processed, which features the non-linear model. In practical realization, as neglecting the dynamical change of motor inductance, this paper employs online modification of inductance parameters, according to the flux saturation, then transforms the non-linear equations into linear ones, and so compacts the structure of controller. Thirdly, in view of the maximum torque output is extraordinary requisite when Electrical Vehicle start up, accelerate, and overtake, this paper issues the maximum torque when both inverter and battery capacity is corporeally definite. Fourthly, on-line differentiating and analyzing both rotor's time constants and its flux by using the expanding order reduction and discrete Kalman filter equation are fathomed, in order to realize high-performance trans-vector algorithm, and also the simulation results are presented. Fifthly, the close-loop regenerative brake system, when the EV's torque is set constant, is deduced; at the same time, unification of electric drive model and brake model is executed. Combined with maximum charge current demands, the mathematical model for online yielding torque as a demand.

本论文针对车载异步电机在矢量控制器所遇到的问题：定转子电阻随温度变化及随电机饱和程度变化的转子电感及定子电感而影响电机调速性能提出一套完整的解决方案：分析了电流型逆变器和电压型逆变器在实现矢量控制时控制器参数的计算，分析出对于电流型逆变器在采用定子磁场定向时，其性能同时具有矢量控制和直接转矩控制两者的优势，并对电压型逆变器在转子磁场定向下的模型进行了仿真研究；建立异步电机非线性模型，推导出考虑磁饱和时异步电机在同步旋转坐标系及静止坐标系下的方程，并做出了仿真结果，建立异步电机在非线性模型下的矢量控制调节器的PI参数设计，在实际应用中，若忽略电机电感的动态变化，可以根据当前的磁路饱和状态而在线修正电感参数，从而将非线性方程线性化，降低控制器的复杂度；考虑到电动汽车在起动和加速超车时需要电机有最大转矩输出，本文讨论在逆变器容量一定和电池供电能力有限的情况下电机最大转矩输出问题；推导了异步电机扩展降阶、离散卡尔曼滤波方程在线辨识转子时间常数和转子磁通，用于实现高性能的矢量控制算法，并给出了仿真结果；推导出了电动汽车恒转矩给定的闭环回馈制动系统，实现了电动控制模型和制动模型的统一，而且结合铅酸电池最大充电电流的要求，为制动转矩在线给定建立了数学模型；设计了基于双DSP系统的高性能矢量控制器软硬件框图，并以大量实验数据说明矢量控制在电动汽车应用的实际应用状况。

By means of forced synchronization of current in thyristor branch with the line current, the mode switching from capacitive mode to Bypass can be implemented. In the switching strategy from capacitive mode to inductive veriner mode, a method of thyristor conditional firing is put forward. The thyristors will be fired and conducted on condition that both line current and capacitor voltage are inphase.

通过强制晶闸管支路电流与线路电流同步，实现由容性区到Bypass模式的切换；在由容性区到感性微调模式切换的过程中提出了晶闸管条件触发的方法，即当线路电流和电容电压满足同向条件时晶闸管才触发导通。

These two pairs exhibit different offsets and bias currents, so when the applied input common-mode voltage changes, the AMPLIFIER input offset voltage and input bias current does also.

由于这两个差分对有不同的失调电流和偏置电流，因此加到输入共模电压变化，放大器的输入偏置电压和输入偏压电流也跟着改变。

It is shown from the accelerated lifetime test and noise measurement for integrated operational amplifiers that if their failure is caused by the drift of input bias current or input offset current, the drift is strongly correlated with 1/f noise current in these devices, and both are proportional approximately.

摘要寿命试验和噪声测试结果表明，如果集成运算放大器的主要失效模式是输入偏置电流或失调电流随时间的漂移，则这种漂移量与运放的1/f噪声电流具有强相关性，二者近似呈正比关系。

The input offset voltage is fixed for a particular amplifier, however the contribution due to input bias current is dependent on the circuit configuration used. For minimum offset voltage at the amplifier input without circuit adjustment the source resistance for both inputs should be equal.

对于一个给定的OP，输入失调电压就已经给定了，但是由输入失调电流所带来的失调电压与所采用的电路结构有关系为了减小输入偏置电流所带来的失调电压，应该使得使得同、反相输入端对地的直流电阻相等，使得由于偏置电流在输入电阻上压降所带来的失调电压相互抵消。

The Electrochemical measurement system used to perform DPSV measurement is constructed with two parts, a low-current measurement system consists of low input bias current operational amplifier and a high resolution SAR ADC and a potentialstat consists of high resolution DAC and high current buffer amplifier.

对于差分脉冲伏安溶出测量，我们使用高精度连续逼近寄存器型ADC和低偏置电流运放构成微电流采样系统；使用高精度DAC和高速大电流缓冲放大器构成了恒电位计，在微控制器的控制下组成电化学测量系统。

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起初我只晓得布鲁克雷德丝是美国少男少女崇拜的偶像，后来回台湾，甚至去年在北京，居然也四处看见她的海报，才惊讶她的魅力之大。