ECONOMYNEXT – Sri Lanka’s energy regulator has demanded the Ceylon Electricity Board (CEB) explain reasons for recent islanwide power failures and recommended measures to prevent their recurrence, saying some of its practices were risky.
The Public Utilities Commission of Sri Lanka (PUCSL) has told the CEB, the state power utility, that a “single element failure” in the power system should not result in islandwide power failures.
“It is the responsibility of the transmission licensee (CEB) to maintain an uninterrupted power supply throughout the country, which has been violated three times in the last six months by way of islandwide power failures,” the PUCSL told the CEB.
It asked the CEB management to inform the PUCSL on action CEB has taken to prevent repetition of islandwide power failures after the first recent one in 27 September 2015.
That was followed by two more islandwide power failures, on 25 February 2016 and 13 March 2016.
The PUCSL said that it hired the Manitoba HVDC Research Centre (MHRC) to do a study after the September 2015 failure, identify shortcomings and make recommendations ro prevent recurrence of power cuts.
The MHRC has said the dynamic transmission system model used by CEB transmission planning and system control branches are not accurate enough for dynamic response analysis.
It recommended the CEB maintain the system steady state voltage within plus or minus 5%, which is the international practice.
The present CEB practice of ±10% tolerance for voltage control on its transmission lines is “risky considering that this limit is very close to overcurrent protection limit of many system devices,” the PUCSL has noted.