A New Algorithm to Avoid Maloperation of Transformer Differential Protection in Substations With an Inner Bridge Connection

Control of unusual mal-operation of three-phase power transformer differential protection due to ultra saturation phenomenon based on Clarke׳s Transform and Discrete Wavelet Transform

“…Therefore, the data from power transformer and current transformers have been taken from Irantransfo Co. in Zanjan, Iran. For modeling the ultra-saturation phenomenon, i pa , i pb , i pc , i a , i b , i c , φ a , φ b and φ c can be solved from (1-4), (11)(12)(13)(14)(15)(16) and (23)(24)(25)(26)(27)(28)(29). i pa , i pb , i pc , i a , i b and i c are the primary and secondary currents of the three-phase power transformer.…”

“…Several studies have been done to distinguish internal faults from external faults and the magnetic inrush current by various algorithms such as the harmonic restraint [8] and the park transform [9]. Also, some works have used special algorithms such as the support vector machine-based protection scheme [10], the self-adaptive transformer differential protection [11], the timedomain analysis of differential power signal [12], the inner bridge connection [13], the standard 87 T differential protection for power transformer and special power transformer [14,15] the intelligent hybrid systems [16], moving windows [17], S-transform [18,19], time-frequency analysis [20], differential evolution [21], negative sequence analysis [22] and S-transform and fuzzy expert system [23] to distinguish between the transient phenomena. But, none of these studies have modeled the ultrasaturation phenomenon.…”

Investigation into the Physical Mechanism and Influencing Factors of Sympathetic Inrush for Transformers in Series

“…However, the initial inrush and sympathetic inrush decay more slowly than the energization inrush in the single transformer due to the sympathetic interaction between the transformers [7]. Current transformer saturation caused by the long-lasting inrush current can decrease the second harmonic content, potentially causing the second harmonic restraint algorithm to fail [8][9][10]. Then, maloperation of the current differential protection of the in-service transformer will occur.…”

A new model to study ultra-saturation phenomenon during the energization of a loaded three-phase power transformer and its effects on differential protection

“…Several studies have been carried out to distinguish internal faults from external faults and the magnetic inrush current by various algorithms such as the harmonic restraint and the park transform . Also, some works have used special algorithms such as the support vector machine‐based protection scheme , the self‐adaptive transformer differential protection , the time‐domain analysis of differential power signal , the inner bridge connection , the standard 87T differential protection for power transformer and special power transformer , intelligent hybrid systems , moving windows , S‐transform , time‐frequency analysis , differential evolution , negative sequence analysis , and S‐transform and fuzzy expert systems to distinguish between the transient phenomena. But none of these studies have modeled the ultra‐saturation phenomenon.…”