Siemens is set to supply two mobile substations to Saudi Arabia’s transmission system operator after winning the order from the Saudi Electric Company’s National Grid SA.

The firm said it had designed and manufactured the two 380 kV trailer-mounted substations, according to specifications from National Grid SA, to fit in any network area of the kingdom.

The units have a power capacity of up to 502 MVA, making them “the most powerful ever built on a single feeder configuration” according to Siemens. Each substation contains three single-phase autotransformers with a capacity of 167.3 MVA, which makes them the largest transformers for mobile substations Siemens has built to date.

Each mobile substation also contains GIS switchgears, MV/HV cable drums, protection and control systems and auxiliary power supplies. According to Siemens, built-in rotating air bushings mean installation and connection of the units can take place in less than a week and can be carried out with no OEM services.  

“The National Grid SA-Specified mobile substations configuration, jointly customized with Siemens, will allow us to bypass any 380 kV substation in the event of failure or major maintenance work,” said Ali S Al-Rammah, vice-president of National Grid SA and head of the company’s maintenance business line.

“They can also be used as fast-track solutions to connect a new plant to the grid,” he added. “It has been essential to develop a customized technical specification for us to have a plug-and-play solution that we could quickly mobilize and install on our own. It will significantly improve the 380-kV and 132-kV grid resiliency that are the backbone of our power transmission infrastructure.”