Mobile Substations

Utilities / Energy – 2014


The duration of power outages encountered by the client during equipment failure and routine maintenance is a major concern for the economy and safety of people. A solution was required by the customer to reduce the overall outage time and ensure limited operational interruption was experienced when the required rectifications, upgrades or maintenance at a substation with was needed.


Single mobile substation that can operate at various voltages. Mobile substation must be as compact as possible due to space constraints at the operational sites. Rapidly deployable mobile substation with minimal site work to facilitate quick interfacing and operation setup once the substation gets to site (Plug and Play). Components on the mobile substation had to be according to the customers standard specifications to be interchangeable should something fail. Safety is a main priority to ensure safe operating conditions for operators and to safe guard equipment.


A list of the customers’ substations in the area was created indicating the operational voltages and power requirements of each. The design was done to accommodate the maximum required power and the highest operating voltage. We further designed a dual voltage system on the primary and secondary side of the mobile substation to accommodate for the other substations.


One mobile substation can cater for four (4) types of substation voltage configuration:

  • 132kV/33kV (40MVA or less)
  • 132kV/22kV (40MVA or less)
  • 88kV/33kV (40MVA or less)
  • 88kV/22kV (40MVA or less)


Power outages are minimal as the mobile substation can be rapidly installed
at a customer substation if a failure occurs. They don’t need to wait for equipment rectification or new replacement equipment before operation can resume.

The mobile substation is designed to be within road limitations thus does not require special abnormal road surveying and escorts when transported.


With the mobile substation, the customer can install the unit at fixed substations that require rectification or maintenance without having long power outages. The mobile substation is also a great financial benefit to the customer, as they don’t need to keep four (4) different transformers as spares. The mobile substation can also be used on projects for temporary construction power where the infrastructure is in existence or already built.


  • Dual voltage mobile substation – 40MVA 132/88kV // 33/22kV (ODAF Cooling system)
  • Custom-engineered compact trailer with steerable axles to assist with manoeuvrability and parking in space constrained areas.
  • Fully operational system with all primary plant equipment automated (132kV rated and 33kV rated (Circuit breaker, Isolator, Earth switch, Surge arrestor)
  • Fully operational system on the secondary plant (Protection, backup power and communication)
  • Complete mechanical and electrical interlocking system to ensure correct ratio selection.