The expert team which was duly constituted by the Energy Regulation Board (ERB) to investigate the nation-wide power interruption of June 4, 2006, began its work. The team is composed of Engineers from a cross-section of society.
On Tuesday 13th June, 2006, the expert team which was duly constituted by the Energy Regulation Board (ERB) to investigate the nation-wide power interruption of June 4, 2006, began its work. The team is composed of Engineers from a cross-section of society.
Within a broad spectrum of its Terms of Reference (ToR), the team immediately set out to establish the cause and nature of the fault that led to the disturbance on the Zambian transmission network. The team undertook a site visit to Kariba North Power station to have insight into the sequence of events on that fateful day. The visit sought to establish the condition of the ZESA-ZESCO interconnector (tie-line) before, during and after the fault, giving due consideration to the condition and adequacy of the protection system in place.
Through many discussions with management and staff of Kariba North Power station, the team has now established the nature of the fault that led to the loss of stability on our interconnected power system. The team reports that the outage was due to a prolonged bus-bar fault on the 330KV bus-bar at Kariba South Power station in Zimbabwe. It was expected that the fault would have been isolated by either the bus zone protection at the 330KV Kariba South Power station switchyard or by the protection on the tie-line. In either case, the Zambian system would have been isolated from the fault. Regrettably, none of the above protection schemes operated.
Through a Joint Technical Committee (JTC), ZESCO has since engaged their Zimbabwean counterparts at Kariba South Power station in discussions to confirm the circuit arrangements at Kariba South Power station in a bid to establish the cause of the failure of the protection schemes on the ZESA side. The JTC will also carry out an assessment of the condition and adequacy of the protection and protection philosophy on the interconnector.
The expert team is now focusing on analysing the information at hand in order to develop measures and recommendations for the achievement of a well co-ordinated, reliable and stable interconnected power system. It is expected that a comprehensive report on the teamÃ¯Â¿Â½Ã¯Â¿Â½Ã¯Â¿Â½s findings and recommendations shall be in place by Friday 23rd June, 2006.
1 ZESA Ã¯Â¿Â½Ã¯Â¿Â½Ã¯Â¿Â½ Zimbabwe Electricity Supply Authority