China: Eco-friendly mobile substation solution for emergencies

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.

The transformer in the newly developed mobile substation is mounted on a trailer and uses natural ester insulating fluid. This fluid, as well as being biodegradable and therefore environmentally friendly, has a flash and fire point twice that of mineral oil. This overcomes the issue of the lack of fire proof systems. The substation is pre-fabricated, pre-commissioned and has a compact design meaning that it can be transported and installed extremely quickly with little on-site work needed. Thus it can be delivered to anywhere within China in just seven days.This substation is available for lease meaning that the customer doesn’t have to consider investment and maintenance costs.

The advantage of the mobile substation is that grid operators can obtain a fast and flexible way of providing interim power supply in the case of outages or planned maintenance. Combined with the environmental and fire safety benefits of the ester fluid, it becomes an even more attractive package.

„With this eco-friendly mobile substation Siemens Energy Transmission is providing a solution that contributes to a stable and even more resilient grid in the Chinese market. It provides a maximum of operational safety and environmental friendliness and at the same time acts as an eye to the grid as it features a Sensformer®“, says Dr. Beatrix Natter, Executive Vice President Siemens Energy Transmission.

Transmission products play a vital role in the energy value chain. Siemens Energy Transmission offers all key elements including power transformers, gas-insulated and / or air-insulated switchgear and components, individually or bundled, with related engineering. With our global factory network and leading innovations we provide the highest level of quality and reliability to support our customers in achieving their objectives.

The Pretact® concept of Siemens Energy was introduced to maximize the resilience of modern power grids. It comprises a comprehensive set of modular features to prevent and protect transformers and high-voltage products better from operational issues as well as against natural disasters or forced outages. In addition, highly flexible “mobile resilience units” provide a chance to react quickly in case of an emergency or planned maintenance.