Electrical machine and its use as traction transformer or choke

The invention relates to an electrical machine (1) for selective operation as a transformer for an alternating voltage operation or as a choke system for a direct voltage operation. The electrical machine (1) comprises a transformer core (3) with two legs (5, 6), an auxiliary winding (20) with a first auxiliary partial winding (21) wound around a first leg (5) of the transformer core (3) and a second auxiliary partial winding (22) wound around the second leg (6) of the transformer core (3) and electrically connected to the first auxiliary partial winding (21), a high-voltage winding (30) with a first high-voltage partial winding (31) wound around the first auxiliary partial winding (21) and a second high-voltage partial winding (32) wound around the second auxiliary partial winding (22) and electrically connected to the first high-voltage partial winding (31), a first traction winding (40) wound around the first high-voltage partial winding (31), and a second traction winding (50) wound around the second high-voltage partial winding (32). Optionally, a first direct-voltage winding (60) is wound around the first traction winding (40) and a second direct-voltage winding (70) is wound around the second traction winding (50).