An electrical substation for transferring power from a main power supply line of a main AC power supply system to an AC distribution system for distributing power to at least a first power consumer, the electrical substation comprising: an auxiliary transformer, a main transformer, a first busbar coupled to the AC distribution system, a second busbar configured for carrying power at a higher voltage than the first busbar but at a lower voltage than the main power supply line, an AC power source connected to the first busbar, and a control system, the auxiliary transformer having a first low-voltage winding and a third high-voltage winding, the auxiliary transformer being connected via the first low-voltage winding to the first busbar and via the third high-voltage winding to the second busbar, the main transformer having a fourth low-voltage winding and a fifth winding, the main transformer being connected via the fourth low-voltage winding to the second busbar and via the fifth winding to the main power supply line, characterized in that: the auxiliary transformer further has a second low-voltage winding, the auxiliary transformer being connected to the first busbar via the second low-voltage winding, the control system being configured, following an interruption of power supply from the main power supply line, to: power the first power consumer via the first busbar, with power from the AC power source, energize the auxiliary transformer via the second low-voltage winding of the auxiliary transformer, via the first busbar, with power from the AC power source, pre-magnetize the main transformer via the fourth low-voltage winding of the main transformer, via the second low-voltage winding of the auxiliary transformer, via the first busbar, with power from the AC power source, synchronize a first condition of a first electrical conducting line connected to the fifth high-voltage-winding and a second condition of the main power supply line, and energize the main transformer with power from the main power supply line. an auxiliary transformer, a main transformer, a first busbar coupled to the AC distribution system, a second busbar configured for carrying power at a higher voltage than the first busbar but at a lower voltage than the main power supply line, an AC power source connected to the first busbar, and a control system, the auxiliary transformer having a first low-voltage winding and a third high-voltage winding, the auxiliary transformer being connected via the first low-voltage winding to the first busbar and via the third high-voltage winding to the second busbar, the main transformer having a fourth low-voltage winding and a fifth winding, the main transformer being connected via the fourth low-voltage winding to the second busbar and via the fifth winding to the main power supply line, characterized in that: the auxiliary transformer further has a second low-voltage winding, the auxiliary transformer being connected to the first busbar via the second low-voltage winding, the control system being configured, following an interruption of power supply from the main power supply line, to: power the first power consumer via the first busbar, with power from the AC power source, energize the auxiliary transformer via the second low-voltage winding of the auxiliary transformer, via the first busbar, with power from the AC power source, pre-magnetize the main transformer via the fourth low-voltage winding of the main transformer, via the second low-voltage winding of the auxiliary transformer, via the first busbar, with power from the AC power source, synchronize a first condition of a first electrical conducting line connected to the fifth high-voltage-winding and a second condition of the main power supply line, and energize the main transformer with power from the main power supply line. the auxiliary transformer further has a second low-voltage winding, the auxiliary transformer being connected to the first busbar via the second low-voltage winding, the control system being configured, following an interruption of power supply from the main power supply line, to: power the first power consumer via the first busbar, with power from the AC power source, energize the auxiliary transformer via the second low-voltage winding of the auxiliary transformer, via the first busbar, with power from the AC power source, pre-magnetize the main transformer via the fourth low-voltage winding of the main transformer, via the second low-voltage winding of the auxiliary transformer, via the first busbar, with power from the AC power source, synchronize a first condition of a first electrical conducting line connected to the fifth high-voltage-winding and a second condition of the main power supply line, and energize the main transformer with power from the main power supply line. power the first power consumer via the first busbar, with power from the AC power source, energize the auxiliary transformer via the second low-voltage winding of the auxiliary transformer, via the first busbar, with power from the AC power source, pre-magnetize the main transformer via the fourth low-voltage winding of the main transformer, via the second low-voltage winding of the auxiliary transformer, via the first busbar, with power from the AC power source, synchronize a first condition of a first electrical conducting line connected to the fifth high-voltage-winding and a second condition of the main power supply line, and energize the main transformer with power from the main power supply line.