The Technology Analysis Of Earth Fault Protection In Non-solid Grounded System

Single phase to ground fault is universally occurred in Non-Solid Earthed Network, Due to some defects in detection principle,apparatus design & maintenance and engineering service etc, It is quite difficult to detect the fault and identify faulty line reliability in worldwide. Therefore, those methods of line selection is doubted &criticized. Recently years,with high reliability of power supply being demanded, faulty line selection has been payed more attention obviously. Intelligence make a deep analysis,and more and more methods of line selection have been put forward, meanwhile new production based on new principle was designed and applicated in utility. However, As ground fault is much complicated,those apparatus performs different, some of them can not make satisfied test result, even some does not work in substation and have to be abandoned. But this situation has not been fed back. Therefore a new problem user has to face, that is how to choose the right product from them, and how to comment on these methods,and what is the standard? This paper discuss and analyze each principle and put forward the standardsMain cotents of this dissertation are as follows:1.,Based on consult large amount articles, this paper summaries the mainly methods of faulty line selection in Non- Solid Earthed Network, introduces the basic principle, such as hamonic method, active compenent method, injecting signal method, the shunt resistance method, the remnant current increment method, the small disturbance method, the traveling wave method, the initial polarity method, the transient signals method, integrated method and so on.2,Based on the fault characteristics of Non-Solid Earthed Network system, analyzes in detail the cause of influence on faulty line selection, gives preliminary comment standard:the performance of the method about reliability, security, enconomical, applicability and serviceability. In order to make reference for user to choose equipment.3,Introduces an new earth fault detection, base on the principle of the transient signals method and result of EMTP in Non-Solid Earthed Network. Also gives various fault type waveforms recorded by the apparatus。...