Travelling Wave Fault Location Technology Base On Electronic Instrument Transformer In Smart Substation

The technology of fault location based on the principle of traveling wave was applied in recent years. Precise location, however, greatly reduced the blackout caused by line malfunction. Still the fault location equipment faces trouble in smart substation. Traditional substation obtains the property of high-frequency traveling wave by using electromagnetism CP/PT. The newly developed electronic instrument transformer does not run efficiently in sample taking, since it is design with the consideration of protecting the measuring equipment.Generally, in electronic instrument transformer, the sampling frequency is rated below 15 kHz, with which, the equipment can be protected, while wave of this frequency is not applicable in traveling wave location, which often requires waves of at least 100 kHz. Then a problem occurs, the solution of which needs noticing two aspects. On the one hand, the high-speed line is required to promote the sampling efficiency; on the other hand, the traveling wave location equipment needs improvement to receive digital signal by electronic instrument transformer and obtaining the temporary traveling wave property.Intelligent transform sub-station usually applies IEC61850 protocol, however, due to the special characteristics of traveling wave in transmission and property, IEC61850 does not stipulate concerning standards. Therefore, two aspects have to be considered that the smart substation is capable of traveling wave fault location. For one thing, the obtaining of traveling signal; for another, a publicly recognized protocol of electronic instrument transformer.This thesis mainly introduces the smart substation, which is the key factor in intelligent grid and also an innovation of traditional substation. Also it analyzes the impact of this innovation to the first or secondary equipment and elaborates problems and solution of electronic instrument transformer providing digital signal in traveling wave location. Besides, the technological development of traveling wave sampling equipment is stated and signal transmission and the protocol of obtaining background location data is introduced.