Impact of load variations on arcing fault detection in LV distribution networks

LV networks have always their own difficulties regarding fault detection and location methods as compared with either MV or LV ones. Among these problems, detecting and locating high impedance faults still represent the most challenging problem. Load types as well as load variations may play a remarkable role for profiling the harmonic contents of voltage and current signals during faulty and nonfaulty conditions. Such conditions are expected to affect the performance of their associated protective elements remarkably. The impacts of these situations on detecting downed conductors in LV networks are investigated in this paper. For this target, a dedicated experimental setup was structured with a 3-phase 400/230 V, 12 mm overhead conductor supplying a variety of loading types. Three phase (3 kW) static load resistors, two 7.5 kW three phase induction motors (fed with either direct or inverter feeding) and 3.5 kW single phase induction motor (air conditioner) represent the variety of the considered loads. The feeding conductors was arranged to create a variety of downed conductor conditions including source-side, downed loading-side with back-infeed and downed energized conductors. The obtained results will assist to realize a better understanding of the properties of these faults and supervise further research steps aiming to get an economic, versatile and dependable detector for such faults.