Controlling harmonics and improving power quality

Sohar Aluminium in Oman, one of the world’s largest aluminium smelter facilities, employed a customised power quality solution from ABB to address a harmonics issue during its smelting process.

Sohar Aluminium produces more than 360,000 t of aluminium annually and is also one of the biggest power consumers in Oman. The smelting process was creating high levels of harmonics, and it was crucial these were kept under control in order to adhere to grid codes and stay connected to the Oman power grid. It was also important the harmonics did not affect other customers on the grid.

“As a leading specialist on power factor correction, we contacted ABB to assist with the design and installation of harmonic filters to reduce the amount of harmonics generated by our smelting process,” said Edward Hough, electrical engineer at Sohar Aluminium.

Harmonics are similar to electrical pollution created by non-linear loads. If harmonics in a network are too high, it can result in forced ageing as well as overload and tripping of electrical equipment. High harmonics also interfere with the smooth operation of electronic equipment, like computers and UPS systems, and can increase network losses. Many utilities impose penalties for non-compliance with harmonic regulations and grid codes.

ABB delivered a turnkey solution including a study of the harmonics in the plant as well as the design, supply, installation, testing and commissioning of a harmonic filter system. The power quality solution comprises four harmonic filter banks at 55 MVAR and high-voltage switchgear.

The filter system has solved power quality issues with regard to harmonics and reactive power and allows Sohar Aluminium to connect to the Oman grid without any compliance issues. The system has also improved power quality in the smelter facility and reduced electrical losses.

Learn more about the case study in this video: