JPS TO Discuss Preliminary Findings of Outage Investigation with OUR

JPS has advised that a preliminary report on the August 27 all-island outage was submitted to the Minister of Energy and the Office of Utilities Regulation (OUR) yesterday, Monday, August 29. A meeting is scheduled with the OUR for this afternoon, to discuss the initial findings.

The report confirms that the outage was caused by a procedural error during scheduled maintenance work at the Port Authority of Jamaica (PAJ) substation in Kingston. Indications are that the team carrying out the work did not completely adhere to the established procedures for the work being done. This error resulted in the worst type of electrical fault possible on a power system.

“The severity of the fault, and the proximity of the fault to the generating plant at Hunts Bay, combined to create instability on the grid, which triggered the system shut-down,” explained Kelly Tomblin, JPS President & CEO.

“The normal protection system responded immediately and performed appropriately,” she indicated. “However, the degree of instability instigated by the fault caused the generating units to trip offline which, in turn, caused cascading events that led to the system shut down. From a system protection standpoint, it did just what it was designed to do---protect the system and the billions of dollars of capital investment from long term damage. This is the normal response of the protection system when there is a severe fault on the grid. It is designed to shut down, to protect itself from permanent damage, and to allow the utility to recover quickly in order to begin restoration of customers’ supply almost immediately after an event like this,” the CEO said.

The only significant questions left relate to the enhanced protection measures that were recently implemented and the behaviour of the earliest generation units that went off line.  “We are trying to determine whether the enhanced system should have prevented the shut down and whether the power plants behaved according to code. Part of the investigation will include dynamic computer modelling to assess the behaviour of the grid and the generating units under the similar conditions,” Tomblin said.

In the meantime, in keeping with its internal processes, JPS has suspended two employees involved in Saturday’s incident, as the Company continues its investigations into the incident.