محمد لعل حقاني

Broken conductor faults in power systems occur when electric current path towards loads is unintentionally interrupted due to damage to conductors feeding the loads. Such faults can lead to many problems and risks, including fire hazards, risks to human lives, and damage to electrical equipment. In this thesis, two methods are proposed to identify broken conductor faults focusing on 20kV and low voltage distribution systems. In the first part, a current-based method is proposed to identify open phase faults in systems with a closed ring structure containing multiple sources. By measuring injected source currents and sending the synchronized information to the main relay, the proposed method is able to detect broken conductor faults and distinguish them from normal operating conditions. Moreover, in the continuation of this section, by modifying the proposed method, a scheme to significantly reduce the amount of information sent to the main relay is established. The proposed method is thereafter simulated and eva‎luated on a closed ring system. The results obtained from the simulations show the capability of the proposed method in detecting and also correctly classifying broken conductor faults. In the second part of the thesis, the transient behavior of broken conductor faults in a simple low-voltage system in laboratory environment, under different load types (resistive-inductive, motor-resistive and dimeric) is investigated. These studies have been conducted by sampling the current of the loads during the occurrence of broken conductor faults and with a sampling frequency of 50 kHz via an oscilloscope. In the following, by using the collected data and comparing them with normal operating conditions (load outage by low voltage switches), a method based on TT transform and random forest algorithm is proposed to detect broken conductor faults under the investigated conditions. The accuracy of this method on the collected data is 92.5%.

خطاي قطع هادي , خطاي امپدانس بالا , سيستم توزيع الكتريكي , حفاظت , سيستم قدرت

Broken Conductor Faults , High Impedance Faults , Power Distribution Systems , Protection , Power Systems

Mohammad Lal Haghani

Prof. Seyyed Mohammad Shahrtash