Power suppliers Eskom Uganda Limited have publicly apologized to Ugandans for the blackout that was experienced on Wednesday evening; and promised that everything is being done to ensure that the incident does not happen again.
The operations manager Eskom Uganda limited, Peter Tentena issued a press statement on Thursday in which the company commits to ensuring excellent asset care.
“Eskom Uganda Limited regrets the power interruption that occurred on 27th day of July 2016 during the peak time. The incident is the first of its kind in the last 13 years of our operations” he said.
According to Tentena, at around 19:14 hours, a system disturbance was experienced leading to loss of 163MW of generation at Nalubaale and Kiira power stations leaving only one unit at Kiira with an output of 40MW.
He says the incident coincided with switching on interbus transformer number 1 which was coming out of maintenance.
“At 19:36hrs, the last Kiira unit tripped off the system due to system instability leading to a total loss of power generation from the complex and consequently, a total generation of 201MW was lost in the
incident. This was a significant load loss and impacted the rest of the power system leading to cascaded tripping of the entire power system” he noted.
He adds that the incident was triggered by a bus zone protection trip in the 132KV substation. Bus zone protection is a scheme installed to isolate a section of the bus bar in case of a fault on the specific
system.
Tentena noted that at 20:31hours, reference voltage from Kenya power system was provided by Uganda Electricity Transmission Company limited which enabled synchronization of the unit and within ten minutes, a total of 120MW had been restored for normal operations.
He however assures Ugandans that before the substation was powered again, it was inspected and no permanent fault was found on the bus bar involved in the incident.
“As a precautionary measure, all generators and outgoing lines were switched from the affected bus bars to the alternate to pave way for restoring generation at the complex” he added.