高压器局部放电在线监测技术是最近十来年发展起来的一门新的综合性技术，代表着局放检测技术发展方向，人们对此进行了许多研究，但由于三线监测技术本身的特殊性和性，仍然存在不少的问题急待解决。本文针对撰写的变压器局部放电在线监测系统的方案深入而系统地研究其原理和方法。本文首次对用于变压器放电在线监测的谐振式非磁性芯棒罗戈斯其线圈电流传感器进行了系统的理论和实验研究。提出了谐振式非磁性芯棒罗氏线圈电流传感器检测回路等效电路模型，经理论分析得到了该电流传感器检测回路的函数；提出了工频大主雷电流下电流传感器的核算方法；提出了线圈匝数与谐振式非磁性芯棒罗氏线圈电流传感器的设计奠定了基础。首次提出了基于谐振式非磁性芯棒电流传感器从高压套管取信号方式下的一种抑制变压器外部电磁干扰的方法－定向耦合差动平衡法，研制了一套定向耦合差动平衡系统，研究表明，该方法不仅能有效地抑制外部电磁干扰，而且能对变压器发生局部放电的相序进行初步定位，适用于变压器局部放电在线监测。研制成功了高性能的超声波传感器；对超声波在油箱内的传播规律进行了实验研究；深入研究了电――声定位法和声――声定位法的原理及算法，分别编制了电－声及声――声定位软件；试验结果表明，电－声定位精度比声－声定位高，定位软件具有实用前景。论述了FIR数字滤波窗口设计法的基本原理和设计方法，提出了变压器局部放电在线监测数字化信号的自适应滤波方法，编制了FIR及自适应滤波软件，试验结果表明，数字滤波能有效地抑制固定频率干扰及周期性干扰。提出了一种调速数据采集系统的总体结构方案，详细论述了数据采样板和主控板两大部分的设计原理，并对每块板上的各功能电路进行详细的分析。

The on-line monitoring technique of PD in transformers is a new comprehensive one that was developed during the last ten years. Researchers did s lot of work in this field. Because of the specialty and complexity of on-line monitoring technique, there are many problems that need to be settled urgently. An on-line monitoring technique, there are many problems that need to be settled urgently. An on-line monitoring system of PD in transformer was studied systematically in this paper.Resonant nonmagnetic core Rogowski coil current transducer, applied to on-line monitoring PD in transformers, was first studied. The equivalent circuit model of measuring circuit of Resonant nonmagnetic core Rogowski coil current transducer was presented and its transfer function was obtained through theoretically analyzing. The accounting method of current transducer under large power frequency current and lightning current was presented. The theoretical formula of relationship between the number of turns of Rogowski coil and the sensitivity of current transducer was presented.The directional difference balance method, which employed resonant nonmagnetic core current transducer to induce signal from HV bushing, was first presented. The experiment result indicated that this method not only could suppress the external electromagnetic interference of transformers, but also could locate the PD point. It was suitable for on-line monitoring PD in transformers.The high quality supersonic transducer was developed successfully. The principle and method of PD location were studied and the PD location software was developed.The FIR digital filter, which was applied in on-line monitoring PD, was proposed at adaptive filtering method, which was applied in on-line monitoring PD was proposed at the same time. The FIR digital filtering software and adaptive filtering software were programmed respectively. The experiment result indicated that the adaptive filtering could suppress cyclical interference efficiently.The total structure of a high-speed data sampling system was proposed. The design principle of data sampling board and main controlling board were analyzed.