Open Access. Generating maximum overvoltages in ferroresonant processes during single-phase arc shorts in ship low-voltage electrical systems
Author(s) -
И.Е. Кажекин
Publication year - 2020
Publication title -
vestnik astrahanskogo gosudarstvennogo tehničeskogo universiteta. seriâ: morskaâ tehnika i tehnologiâ
Language(s) - English
Resource type - Journals
eISSN - 2225-0352
pISSN - 2073-1574
DOI - 10.24143/2073-1574-2020-1-115-124
Subject(s) - ferroresonance in electricity networks , overvoltage , voltage , ground , mechanics , electrical engineering , physics , control theory (sociology) , engineering , transformer , computer science , control (management) , artificial intelligence
The article discusses processes with single-phase faults in shipboard low-voltage electrical plants with a neutral grounded through a reactor. In such electrical plants, ferroresonant oscillations occur if one of the phases closes to the housing. The oscillations have an influence on the process of generating maximum arc overvoltages during single-phase shorts on the housing. The conditions for appearing ferroresonant phenomena in low-voltage ship electrical networks are studied. The processes in the ferroresonant circuit have been analyzed, the initial conditions necessary for their excitation have been identified. The processes causing the initial conditions in the power supply network that are sufficient for generating ferroresonant oscillations when the phase is closed to the housing have been considered. The conditions favorable for ferroresonant excitation are created due to the behavior of the low-voltage grounding arc and subsequent transient processes in the zero sequence circuit. Maximum overvoltages accompanied by ferroresonant processes occur when the grounding arc is burned in accordance with the theory of Peters and Slepian, that is, when it is extinguished at a moment close to the transition through the zero value of the forced component of the single-phase current short. The arc causes the increased voltages on the neutral grounding elements. As a result, the neutral bias voltage at a constant potential increases significantly. Based on the magnitude of the neutral bias voltage at a constant potential, the effect of ferroresonant oscillations on the maximum overvoltages arising in strong phases is estimated. The quoted formulas help to calculate the maximum values of arc overvoltages. The reliability of the proposed methodology for calculating overvoltages is confirmed by the studies performed on the physical model of the ship electrical network.