Investigation of ferroresonance phenomena in isolated 6 kV power network
Abstract
Ferroresonance is a complex nonlinear electrical phenomenon that can cause significant dielectric and thermal stresses in power equipment, leading to potential faults, equipment damage, power supply interruptions, etc. Three-phase networks with isolated neutral point and single-phase isolated inductive voltage transformers are susceptible to ferroresonance, caused by the interaction of the transformer's nonlinear inductances and zero sequence capacitance of power network. The paper analyzes the possibility of ferroresonance occurrence in a real 6 kV power network, with an isolated neutral point, using the electromagnetic transients program ATP/EMTP. A detailed network model is developed, taking into account the nonlinearity of voltage and power transformers, which is utilized to analyze various configurations, switching operations, and faults in the network that could trigger ferroresonance. It is shown that, under certain circumstances, ferroresonance can occur, with faults clearing being the most common initiators of ferroresonance. The efficiency of different measures to suppress ferroresonance is also analyzed. The impact of the resistance values of voltage transformer’s open delta winding dumping resistor on the suppression of ferroresonance occurrence, is considered.
References
[2]. IEC TR 61869-102:2014 Instrument transformers: “Ferroresonance oscillations in substations with inductive voltage transformers”, 2014, ISBN 978-2-8322-1308-7.
[3]. Jovan Mrvić, “Naponski transformatori i ferorezonansa u izolovanim mrežama”, Magistarski rad, Elektrotehnički fakultet u Beogradu, 2014.
[4]. Studija broj 310902, “Eksperimentalan istraživanja prelaznih faznih napona i struja u mrežama 35 kV, 20 kV, 10 kV i 6 kV“, Elektrotehnički institut ''Nikola Tesla'' Beograd 2009.
[5]. BRÄUNLICH R., DÄUMLING H., HOFSTETTER M., PRUCKER U., SCHMID J., SCHLIERF H. W., MINKNER R. Ferroresonanzschwingungen in Hoch- und Mittelspannungsnetzen Teil 1: Definitionen und allgemeine Erklärungen. Bulletin SEV/AES 2006, Heft 23, pp. 17-22.
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