Keeping the lights on is one of the main drivers of the Siemens Energy Pretact® concept for maximized grid resilience. A major step has now been taken by the Siemens Energy plant in Wuhan that had already been a forerunner of mobile substation technology with conventional transformers. The newly developed mobile substation combines the resilience-focus of the Pretact® concept with the latest innovation of digitally connected transformers - a 40 MVA / 110 kV Sensformer® filled with natural ester oil. It also includes a 126 kV highly integrated switchgear, a 126 kV surge arrester and a 12 kV gas-insulated switchgear (GIS).
A mobile substation performs the job of a normal substation; but instead of being static, it is mounted on a semi-truck or trailer for easy transportation to wherever it may be needed. This makes it ideal for ensuring an interim power supply when there is an outage or during planned maintenance work. However, it is not as simple as putting the components of a substation onto a trailer. There is usually no possibility to install fire proof systems such as firewalls and the unit has to be highly portable and quick to install.