The main causes of loss that lowers motor efficiency and causes heat generation are roughly divided into copper loss in the conductor section caused by the drive current and iron loss in the core section caused by the drive voltage. By using an amorphous alloy for the motor core, iron loss can be significantly reduced, and the following effects can be achieved.

To quantify the effect, we prototyped a distributed winding IPM motor with a stator physique of Φ215mm × 50mm, evaluated the loss, and compared the motor efficiency. By using amorphous for the stator, iron loss is reduced to about 1/5, motor efficiency is improved by 3% or more, and it has been confirmed motor thermal generation can be reduced by half. In addition, it has been shown that the efficiency improvement in the high rpm range reaches 2% or more even with the amorphous alloy replacement of only the stator teeth in (b) below.
In this result only the core grade is changed under the same structure and the same drive conditions.
With a motor that has been optimized for its structure and drive conditions on the premise of an amorphous alloy, it is possible to achieve ultra-high-speed rotation, which is difficult with conventional materials, and it is possible to reduce the size and to increase the output of the motor.

Iron loss evaluation result

Efficiency comparison

Stator

Rotor

Silicon Steel (gray area)

Both Stator, Rotor, Silicon Steel

Amorphous (pink area)

Silicon Steel
(gray area)

Only Stator teeth Amorphous

Amorphous (pink area)

Silicon Steel
(gray area)

Stator all Amorphous

(a) Silicon Steel Stator

(b) Amorphous teeth

(c) Amorphous Stator

Y.Enomoto et al. : " Evaluation of a Motor with an Amorphous Iron Core Punched by a Die", IEEJ Journal of Industry Application vol.10No.6 pp.785-792 (2021)