Siemens has been awarded an order to supply two mobile substations to National Grid SA, the transmission operator of Saudi Electricity Company.
Based on the unique specifications from National Grid SA, Siemens has combined its existing mobile substation modules to design and manufacture two 380kV mobile substations that are able to fit and suit in any network area of the Kingdom. With a rating of 502 megavolt amperes (MVA) each, these two high-voltage mobile substations will be the most powerful ever built in a single feeder configuration.
A mobile substation is mounted on a special trailer and can easily be transported where needed. Thanks to their built-in rotating air bushings, their installation and connection time is reduced to less than one week and can be executed with no equipment manufacturer services.
Mobile substations are a fast and versatile solution for emergency power restoration or fast-track grid connection that also guarantees the utmost reliability. They also support heavy maintenance or renovation work as an interim bypass substation that can easily be set up to reduce or eliminate power outages.
Mirko Düsel, CEO of the transmission solutions business unit at Siemens Energy Management, said: “We are pleased that our mobile substations will provide our customer, National Grid SA, with three crucial aspects of a safe power supply: agility for grid reinforcement projects, grid resilience to failures and flexibility in operation, maintenance and renovation.”
With a voltage of 380 kilovolts (kV) and a power capacity of up to 502 MVA, the two substations are the most powerful ever built on a single feeder configuration. One substation contains three single-phase autotransformers with a capacity of 167.3 MVA each, which makes them the largest transformers for mobile substations ever built at Siemens.
Ali S. Al-Rammah, vice president of National Grid SA and head of the company’s maintenance business line, said: “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.”
He added: “They can also be used as fast-track solutions to connect a new plant to the grid. 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 resilience that are the backbone of our power transmission infrastructure.”

Source: Arab News