چكيده به لاتين
Abstract
In this thesis, three new algorithms for fault detection in transmission lines are proposed. The proposed algorithms are based on the voltage signal which suffers from decrements after fault inception.The first algorithm is proposed on the fact that the sum of the samples of one cycle of voltage signal in normal conditions is equal zero. However, in the fault situation this balance will break down. The second proposed algorithm employs the adaptive cumulative sum method (ACUSUM) to detect fault. The last algorithm is the reverse adaptive cumulative sum method (RACUSUM) which detects faults like ACUSUM but in reverse manner. In the dependability investigation, the three algorithms can detect all faults in different inception angles at different buses with source impedance ratio (SIR) more than 0.172 in the detection stage. However the RACUSUM algorithm can detect faults at buses with SIR less than 0.172 in the protection stage. To investigate the security of the proposed algorithms, different types of voltage disturbances are applied to the system and in all cases the security is conserved in the three algorithms.
Keywords—Fault detection, voltage-based, voltage instability, protection, transmission lines, source impedance ratio.
