Integration of multi-algorithm for single-phase fault detection in distribution system with arc suppression coil grounding using extenics

A new integrated fault line detecting method using extenics is proposed, for existing methods of fault line detection are affected by fault switching angle and electric arc etc., the accuracy of fault line detection is not satisfied. Three factors of matter-element in single-phase fault line detection are confirmed, which are the possible fault line's aggregate and its correlative characteristic aggregate and quantity field with the stated characteristic. The characteristic aggregate includes the decaying direct current component, the D-value of transient energy, the D-value of reactive power and the correlation coefficient. The relation function of extended aggregate is imported, in order to quantificationally calculate the fault degree of each line and confirm the corresponding weight function. Then, the fault line detection is realized. The method integrates four algorithm. It can eliminate not only the effect of the small current of fault line and the unstable grounding electric arc, but also the effect of the capacitance current of the long sound lines when the short line is fault. The method is not affected by the uncertain factors such as the fault switching angle, transition resistance. Large simulations indicate that the fault line detecting method is correct and reliable.