A three-phase transformer, and method of assembling the same, are disclosed. The three-phase transformer comprises three closed-loop magnetic core elements each comprising two pairs of partial primary and secondary coils respectively associated with two different electrical phases of the three-phase transformer. Each pair of partial primary and secondary coils is placed over a same magnetic core section of its closed-loop magnetic core element and its partial primary and secondary coils are respectively electrically connected either in series or in parallel to partial primary and secondary coils of another pair of partial primary and secondary coils associated with the same electrical phase and placed over another one of the closed-loop magnetic core elements. The serially or parallelly electrically connected partial primary coils are electrically coupled for connection to a three-phase electric power supply. The serially or parallely electrically connected secondary coils are electrically coupled for connection to a three-phase load.
