Investigation On The Intellectual Instrument For On-line Monitoring Leakage Current Of MOA

By applying the MOA on-line monitoring technology, we can understand the performance condition of MOA at any time without unnecessary power-cut-off overhaul. Thus we can detect the abnormal phenomena and hidden accidents of MOA in time, take measures in advance to prevent the accident from getting worse and to avoid the economic loss resulted from the accident. In this thesis, a intellectual instrument for on-line monitoring leakage current of MOA was developed. The contents are listed below:(1). Using the Virtual Instrument technology,the Digital Waveform Analysis method based on DFT and the ready module of plural operation in Labwiew and then developing a multi-functional intellectual device for on-line monitoring leakage current of MOA. This device can not only on-line monitor all kinds of parameters of MOA in serve, but also display resistive current waveform, Lisaru Curves, and AC volt-ampere characteristic curves.(2). The idea, measuring the MOA resistive current only depending on current signal without using other ways, which is based on constructing the capacitive fundamental frequency current and the capacitive 3rd harmonic current, has been analyzed experimentally and theoretically.(3). Experiencing on different types of MOA with this device, and then educing several new conclusions. These conclusions can be applied for a new idea which analyzes the MOA resistive current only basing on current signal. (4). Developing the electrical field probe which can get voltage signal indirectly and analyzing how to measure the MOA resistive fundamentalfrequency current and the MOA resistive 3rd harmonic resistive current when the electrical field probe is exposed to single phase power; in theory and in practice, it may be concluded that a new MOA on-line monitoring ways, measuring the MOA resistive fundamental frequency current and the MOA resistive 3rd harmonic resistive current, is applicable in a long run.