ABB has won a $62m order from the South African utility Eskom to strengthen one of the region’s most important cross-border power transmission systems.

ABB will refurbish the HVDC Apollo converter station near


. ABB says that upon completion in May 2008, the refurbishment will improve the reliability of the converter station receiving electricity from



’This refurbishment will significantly increase grid reliability and power flow in this key area,’ said Samir Brikho, head of ABB's Power Systems division. ‘Using our semiconductor valves and control technology, we have already successfully upgraded a number of existing HVDC plants with minimal disruption.’

This HVDC system helps to integrate hydropower produced at the Cahora Bassa dam in


with the grid in

South Africa

, where electricity is mainly produced by coal-burning thermal power plants. The refurbished Apollo converter station, which was constructed in the 1970s, will boost the transmission reliability of the converter station. It will also prepare for future upgrades that may be required.

ABB’s scope of supply includes new thyristor valves with an outdoor design that will reportedly minimise the interruption of supply from Cahora Bassa during the upgrade. The entire control and protection system will be replaced using ABB’s computerized Mach 2 system, and ABB will also supply new AC harmonic and DC filters using DC capacitors.

Earlier this month, ABB won a $30m contract from Eskom for equipment to help strengthen power grid reliability, which marked the largest order for transmission circuit breakers received by ABB.