Effects of electric power blackouts on steam turbine power plants

Abstract

In recent years the phenomenon of complete blackout happened many times in Sudan and
causes several problems and defects in the power generation plants. There are many causes of
power blackouts in Sudan, among them include: plants overloading due to too much power
demand, failure in some power stations which makes the loads heavy on other stations and some
human errors. This resulted in a power loss of over 10 GWH for 6 hours at a single blackout
incidence in 2017. In this study, Khartoum north thermal power plant was taken as a case study
since it is more affected by this phenomenon. In unit No. 6, which is steam power plant, both
shafts of the high and low pressure turbines were seriously defected. Other defects were noticed
in the crankshaft seats and oil rings in high and low pressure turbines. All those defects were
mainly caused by high friction between rotating parts due to insufficient lubrication which
happened when lubricant circulating and oil pumps were suddenly stopped by the complete
blackout. Also some defects were observed in the electrical generator, mainly in the main shaft
and its seats due to same reason mentioned above. To minimize the complete blackout
phenomenon, some recommendations were suggested in this study. First, avoid the plant’s
overloading by installing more power plants to cater for the increase in demand. Second, increase in monitoring of operations and maintenance programs, and finally reduce human errors by
intensive training for all engineers and technicians.