【作者】 王佳琳；

【导师】 任洪林；

【作者基本信息】 哈尔滨工业大学 ， 电力系统及其自动化， 2007， 硕士

【摘要】 在高速发展的电力系统中,对测量装置响应能力的要求越来越高,rogowski线圈电流互感器因具有不饱和、线性度好、动态响应能力强等特性而越来越受到人们的重视。但是,rogowski线圈电流互感器的测量精度容易受到外界环境变化的影响。针对这一问题,设计了自适应rogowski线圈电流互感器。采用带铁心的rogowski线圈电流互感器作为自适应校正系统的基准源。通过对带铁心的rogowski线圈的等效分布参数模型进行大量的仿真,结果表明带铁心的rogowski线圈在未发生饱和时具有很高的测量精度,可以满足自适应校正系统的要求。但在测量大电流时会出现磁饱和现象而产生测量误差。采用多分辨率快速小波分析方法可以对饱和点进行判定。经过对多种情况的仿真分析,结果表明采用小波分析判定带铁心的rogowski线圈的饱和点的方法是正确可行的。由空心rogowski线圈等效模型仿真结果的分析可知,各种外界因素(如装配误差)会降低空心rogowski线圈的测量精度。为此,把控制原理应用到rogowski线圈电流测量系统中,将带铁心的rogowski线圈和空心rogowski线圈相结合,设计了自适应rogowski线圈电流互感器。仿真表明,设计的自适应校正系统可以提高rogowski线圈电流互感器的测量精度,校正因外界环境变化而产生的误差。在前两部分研究的基础上,设计了自适应rogowski线圈电流测量系统的框架,并对积分环节和调制环节进行了研究。设计的带有惯性环节的积分电路把空心rogowski线圈的输出电压恢复成与被测电流信号成比例的信号。调制环节的作用是把采集的模拟量转化成适合光纤传输的数字量。根据测量系统的指标要求,选择A/D7895-10作为A/D转换芯片,设计了A/D芯片工作需要的脉冲发生电路等外围电路,仿真结果表明所设计的外围电路可以使A/D芯片正常工作。更多还原

【Abstract】 With the rapid development of the electrical power system, the demand of responsing ability of measuring devices become higher. Because rogowski coil current transformers not due to saturation, good linearity, and dynamic capabilities. So they are attracting increasing attention. However, the measurement precision of rogowski coil current transformer is vulnerable to be changed in the external environment. And the measurement results when small current is not very good. On this issue, this paper launches a study, and designs an adaptive correction rogowski coil current transformer.Firstly, core rogowski coil current transformer is chosen to be the reference. By lots of simulation of its equivalent model, the result shows it has high precision when the core rogowski coil is not saturated. So it meets the demand of adaptive system. But when electrical power system is fault, core rogowski coil is easy to be saturated. In order to judge the saturation point, fast multiresolution wavelet analysis method is used. The result of simulation shows that it is feasible to use fast multiresolution wavelet analysis to judge the saturation point.Secondly, the influence of external factors can decrease the measuring precision of heart rogowski coil by analyzing the equivalent model of heart rogowski coil. Control principle is applied on current measuring system of rogowski coil. Heart rogowski coil combines with core rogowski coil. Then adaptive rogowski coil current transformer is designed. The result of simulation shows that adaptive system can revise the error brought by external factors and improve the measuring precision of rogowski coil current transformer.Based on the research of the above two sections, structure of adaptive rogowski coil current transformer is designed, and studies on integral circuit and modulation circuit especially. The integral circuit with inertial link can recover the output voltage to be the signal proportional to the measured current. Modulation circuit transforms the analog collected to be digital suitable for optical fiber transmission. A/D7895-10 is chosen to be the chip according to the measuring demand. Then pulse generation circuit which is needed by chip is designed. The result of simulation shows that the designed circuit can provide pulse for A/D chip effectively.更多还原