A fault-tolerant four-phase electric drive system, comprising: a rotary electric machine having a permanent magnet rotor and a stator having eight evenly-spaced coils arranged in pairs, each coil in each pair being separated by 180 degrees; a first phase (ΦA) comprising a first one of the coil pairs and a first phase drive circuit connected therewith; a second phase (ΦB) separated by +45 degrees from the first phase and comprising a second one of the coil pairs and a second phase drive circuit connected therewith; a third phase (ΦC) separated by +90 degrees from the first phase and comprising a third one of the coil pairs and a third phase drive circuit connected therewith; a fourth phase (ΦD) separated by +135 degrees from the first phase and comprising a fourth one of the coil pairs and a fourth phase drive circuit connected therewith; and a controller connected with the first, second, third and fourth phase drive circuits to control operation thereof, characterized in that: the stator is an alternate wound stator; the first phase drive circuit and third phase drive circuit are connected with a first dc bus; and the second phase drive circuit and the fourth phase drive circuit are connected with a second dc bus; the first phase drive circuit, second phase drive circuit, third phase drive circuit, and fourth phase drive circuit are connected with the first dc bus via respective electrical contactors (208, 210, 212, 214) operable by the controller; and the first phase drive circuit, second phase drive circuit, third phase drive circuit, and fourth phase drive circuit are connected with the second dc bus via respective electrical contactors (209, 211, 213, 215) operable by the controller. a rotary electric machine having a permanent magnet rotor and a stator having eight evenly-spaced coils arranged in pairs, each coil in each pair being separated by 180 degrees; a first phase (ΦA) comprising a first one of the coil pairs and a first phase drive circuit connected therewith; a second phase (ΦB) separated by +45 degrees from the first phase and comprising a second one of the coil pairs and a second phase drive circuit connected therewith; a third phase (ΦC) separated by +90 degrees from the first phase and comprising a third one of the coil pairs and a third phase drive circuit connected therewith; a fourth phase (ΦD) separated by +135 degrees from the first phase and comprising a fourth one of the coil pairs and a fourth phase drive circuit connected therewith; and a controller connected with the first, second, third and fourth phase drive circuits to control operation thereof, characterized in that: the stator is an alternate wound stator; the first phase drive circuit and third phase drive circuit are connected with a first dc bus; and the second phase drive circuit and the fourth phase drive circuit are connected with a second dc bus; the first phase drive circuit, second phase drive circuit, third phase drive circuit, and fourth phase drive circuit are connected with the first dc bus via respective electrical contactors (208, 210, 212, 214) operable by the controller; and the first phase drive circuit, second phase drive circuit, third phase drive circuit, and fourth phase drive circuit are connected with the second dc bus via respective electrical contactors (209, 211, 213, 215) operable by the controller. the stator is an alternate wound stator; the first phase drive circuit and third phase drive circuit are connected with a first dc bus; and the second phase drive circuit and the fourth phase drive circuit are connected with a second dc bus; the first phase drive circuit, second phase drive circuit, third phase drive circuit, and fourth phase drive circuit are connected with the first dc bus via respective electrical contactors (208, 210, 212, 214) operable by the controller; and the first phase drive circuit, second phase drive circuit, third phase drive circuit, and fourth phase drive circuit are connected with the second dc bus via respective electrical contactors (209, 211, 213, 215) operable by the controller.