Consulting Projects

Consulting Projects

• Investigation of the causes of two accidents on 160 MVA, 20/230 kV T4 Transformer of Steam Turbine Generator number 4 of Montazer Ghaem Power Plant (under management of Sepehre Energy Company) during 2019 and 2020.

Brief Review of the Study:

This work required a full understanding of the type of connection among the output power transformers of the 4 steam turbine units of this power plant, the type of shielding of their short line connections to the 230 kV substation of the power plant, and research on different possibilities on the location of lightning strike to the 230 kV lines entering the 230 kV substation, and to the short lines between the Steam Turbine units’ power transformers and the 230 kV substation.

The team under supervision of Dr. Mehdi Vakilian, were Mr Mahdi Kazemiun and Mr. Ahmad Khazaeian (Master Students in Electric Power Engineering of Sharif University of Technology). They thoroughly analyzed the two accidents through transient modeling of the Generators, Power Transformers, Lines and lightning arresters of the transformers and the 230 kV substation to understand how the insulation coordination of the substation failed under a lightning strike in the first accident which caused a short circuit on winding of phase B of transformer and it was damaged due to the persistent short circuit that was not cleared and after repair of the power Transformer T4 and substituting the SiC lightning arresters with ZnO arresters, the problems were resolved and the whole circuit was reenergized. However, during another accident which is analyzed by the team using the recorded current and voltage signals by one of the relays of the steam turbine unit the insulation of the repaired power transformer failed under another lightning strike; and finally the analysis is completed and the Sepehre Energy Company received the two reports.

This consulting work has many new research findings that the team are going to publish as the results of their investigations after receiving the permission from

the managing company