international magazine
06-07-2020 09:02


KREMENCHUG REFINERY SURVIVES POWER CUT OFF



KREMENCHUG REFINERY SURVIVES POWER CUT OFF

6th JULY, 2020, 9.00am.
On 4th July, 2020, Kremenchug Oil Refinery (NPZ) stopped for two hours. According to the acting refinery chief engineer Yury Golych, this happened due to an accident at the Ukrenergo substation in Gorishni Plavni. Alarmed residents photographed fire and black smoke clouds.



According to Yury Golych, due to refinery operation interruption, the operators carried out an emergency technical gas release - Since this was a day off, we promptly had to call everyone back to work: engineers, electricians. An emergency discharge of gas to flares had to be carried out, this is normal in emergency situations,” Yury Golych explained. He added that such situation at the refinery happened for the first time in 55 years.

According to preliminary estimates, the Ukrenergo substation had an accident with fire, explosion, which led to the voltage drop in the transmission lines. Accordingly, this main substation feeds the power plant, as well as the Fakel (Flare) substation, which is a backup power unit for the refinery. It so happened that at the refinery, in addition to the main consumer, the reserve consumer also failed for a certain period of time. “This substation belongs to Ukrenergo,” explained Yury Golych. According to preliminary information, a 150 kV transformer exploded at the Ukrenergo substation, which led to a voltage drop.

In addition, the refinery experts specified that the power supply scheme of UkrTatNafta refinery provides for the supply of voltage from two substations - on the side of 6 kV from the Kremenchug Power grid and on the side of 150 kV from the Fakel (Flare) station, for which one of the sources is bus 150 kV station of 330 kV Kremenchug power grid. An accident occurred at the Kremenchug substation with the disconnection of 3 and 4 Bus systems 150kV resulting from the arc flash protection.

National Energy Company Ukrenergo informed that the voltage loss was related to the damage to the client’s (that is, one that belongs to the consumer) current transformer in the 150kV connection block “Career No. 1” and the 3rd and 4th sections of 150kV bus sections being disconnected by the protection.

At the same time, all 150kV lines that lost power from the Kremenchug substation in the indicated period belong to the Erestivsky and Poltava mining and processing enterprises (GOK) and are not related to the power supply scheme of the Kremenchug refinery. A short circuit during an emergency was accompanied by significant decrease in voltage in the adjacent 150kV network.

The Kremenchug refinery experts investigate whether this could have lead to malfunction of the technological units at the refinery.