【作者】 翟学明；

【导师】 朱永利；

【作者基本信息】 华北电力大学 ， 电力系统及其自动化， 2012， 博士

【摘要】 绝缘子泄漏电流的高精度检测是准确掌握绝缘子运行状态基础而关键的环节；泄漏电流数据的高效压缩又是保障绝缘子状态监测实时性的重要手段。论文围绕这两个课题开展了深入的研究。论文详细研究了泄漏电流传感器存在误差的根源,得出的结论是：励磁电流带来稳态误差；局部磁滞和宽频带引起的传感器回路参数变化导致暂态误差,也是目前现有误差补偿方法所忽视的问题。现有零磁通误差补偿方法不能满足泄漏电流传感器宽频带大量程高精度检测的要求。针对泄漏电流传感器宽频带高精度的要求,提出了“微磁变”动态误差补偿方法。从理论角度研究了它的误差补偿模型,对补偿过程中的微磁变暂态特性进行了数学分析,并给出了稳态误差和暂态误差的基本计算方法。运用“微磁变”误差补偿数学模型,深入分析了励磁电流、磁滞以及宽频带信号对传感器产生的影响。基于“微磁变”误差补偿方法,提出了一种宽频带、高精度带铁芯的Rogowski泄漏电流传感器设计方案。分四种情形对研制的传感器进行了实验,结果表明：该传感器在给定的量程和频率范围内均达到很高的测量精度和线性度,对于瞬变电流信号有很好的暂态响应特性。针对钳式电流传感器在现场安装过程中气隙大小不一致产生的诸多问题,以及传感器电子电路存在温漂问题,提出了采用基于标准电流注入的在线定标方法。论文详细论述了该方法的原理、定标过程和实验结果。目前的测量技术很难在宽量程时达到高精度和高分辨率要求,针对这一矛盾,提出了基于施密特触发的宽量程多分辨率泄漏电流测量方法,设计了基于施密特方式的档位切换控制策略,实验验证了提出方法的有效性。针对泄漏电流数据的周期非平稳特征,提出了基于预测编码和自适应SPIHT的泄漏电流数据组合压缩方法。实验表明该方法在压缩性能和计算速度上有明显优势。将研制的泄漏电流电流传感器应用于高压输电线路监测系统。运行结果表明,该传感器能够满足绝缘子泄漏电流的高精度测量要求。更多还原

【Abstract】 Insulator leakage current detection of high accuracy is a fundamental and key link to know the operating state of an insulator well and exactly. Efficient data compression on its leakage current signal is an important means to guarantee the real-time performance of an insulator state monitoring system. The research relating to this dissertation is focused on the above these two issues.Through analyzing the error sources of leakage current transducers in details, we can obtain the following conclusions:(1) an excitation current brings the steady-state error;(2) the local magnetic hysteresis and parameters change of broadband transducer circuit causes the transient error, which is just neglected in current error compensation methods. The existing zero-flux error compensation method can’t meet the requirements for a leakage current transducer of broadband, wide range and high accuracy.To meet for the requirements of a leakage current transducer on high accurate and broadband charactistics, micro-flux-variation dynamic error compensation method is proposed in this dissertation. Its error compensation model is studied theortically. The mathematical analysis to its transient micro-flux-variation characteristics in the compensation process is presented, and the basic calculation methods of steady-state error and transient error are given. With micro-flux-variation error compensation mathematical model, the influence to the proposed transducer by the exciting current, hysteresis and broadband signal is discussed deeply.A design scheme of Rogowski leakage current transducer of broadband and high accuracy with iron core is proposed based on the micro-flux-variation error compensation method. Experiments with four kinds of situations are carried out on the developed transducer. Results show the transducer has higher accuracy and better linearity within the given amplitude range and frequency band, and has a very good transient response to a transient current signal.To solve numerous problems resulting from the different gaps of the clamped-on leakage current transducers in their field installation, and the temperature drift of electronic circuits, an online calibrating method is put forward based on given current injection. The principle, calibrating process and experimental results of this method is stated in details.It is diffcult to achieve high resolution under wide-range for a measurement with current technology. To solve this problem, a wide-range and multi-resolution measuring method of the leakage current is proposed based on Schmitt trigger. The control strategies on the output grade switching is designed. The validity of this method is verified through experiments.Considering the non-stationary and periodic characteristics of leakage current data, a combinatorial method on their compression is put forward based on predictive coding and adaptive SPIHT. Experiments show that the method has distinct advantages in compression performance and calculation speed.The developed leakage current transducer has been applied to high voltage transmission line monitoring. Results show that it can meet the requirements of high accurate detection on the insulator leakage current.更多还原