Protection of power transformer using multi criteria decision-making

Experimental results of ratios‐based transformer differential protection scheme

“…Because of the high dependence of transformer parameters on the magnetic curve and leakage inductance, inaccurate measurement of these is the main limitation of voltage and flux restraints, and inductance‐based approaches . Approaches in the literatures need a lot of training and complex computation in addition to being dependent on transformer parameters . In case of an internal fault with fault resistance or energization simultaneously with internal fault, these schemes have some restrictions that may influence the speed and security of the relay.…”

“…Among these are harmonic restraint, 1,2 voltage and flux restraints, 3,4 inductance-based method, 5,6 and digital signal processing. [7][8][9][10] The approaches based on harmonic restraint have limitations with new core steel improvement in modern transformers as inrush current may contain insufficient amount of second harmonics like internal faults. 11 Because of the high dependence of transformer parameters on the magnetic curve and leakage inductance, inaccurate measurement of these is the main limitation of voltage and flux restraints, and inductance-based approaches.…”

“…A number of approaches to distinguish inrush from internal fault currents have been reported in the literature. Among these are harmonic restraint, voltage and flux restraints, inductance‐based method, and digital signal processing . The approaches based on harmonic restraint have limitations with new core steel improvement in modern transformers as inrush current may contain insufficient amount of second harmonics like internal faults .…”

Differential protection scheme for power transformers using matched wavelets

“…However, the algorithm applied for detecting the inrush and fault uses fuzzy‐based inference rather than a simple threshold. In order to get un‐conflicting and correct decision, a relay working on multi‐criteria algorithm using fuzzy‐logic‐based approach for making final trip decision is proposed in [9–11]. The method utilising morphological gradient is also suggested in [12] with promising results.…”

Fuzzy Logic Expert System for Incipient Fault Diagnosis of Power Transformers

“…All these tests have their own significance in evaluating the current health condition of the transformers. For the past three decades, large number of fuzzy logic models has been proposed based several diagnostic tests data, to evaluate the overall health condition and type of incipient fault present in the transformers [7]. Fuzzy logic is highly useful tool to determine the type of incipient fault present in power transformers [8].…”