The definition of mobile substation or portable substation is a completely self-contained trailer mounted substation consists of transformer, cooling equipment, high voltage switchgear and low voltage switchgear along with metering, protection relaying devices, AC and DC auxiliary power supply, surge protection, and cable connecting arrangement.
– As name implies, this is a substation on wheels.
– A mobile substation is a completely self-contained trailer mounted unit comprised of transformer, cooling equipment, high and low voltage circuit protection, metering, relaying, AC and DC auxiliary power supplies and surge protection.
• The mobile substation is intended to be pulled by a truck tractor and for that reason is mounted on a specially designed semi-trailer chassis.
• The design and installation of a mobile substation have specific restrictions which are not present when designing conventional substations.
• D.O.T. restrictions due to transport
– such as limiting dimensions and weights
– Road regulations
– Electrical clearances
In these cases constructing one permanent outdoor or indoor substation for fulfillment of power supply is not economical. Also a mobile substation is required where there is lack of space for constructing out door substation during any big construction work when consumption of huge power by construction machines is required. Mobile substations are also used to quick restore of electrical service during an outage caused by a storm or other disaster. This can also provide temporary power service during construction of permanent facilities. It also can be used as alternate power service during regular maintenance of existing equipment.