An energy efficient brushless drive system for a domestic washing machine

Abstract

The paper describes the design, analysis, simulation, prototyping and testing of a brushless motor drive system for a front loading domestic washing machine. The motor is a radical design, which employs bonded NdFeB magnet material and drives the washing machine drum directly, without the need for conventional gearing systems. An appraisal of the drive system employed in the washing machine is included in the paper, which also identifies the main operational modes and corresponding drive system requirements. The key stages in the design of a new motor are highlighted and the use of electromagnetic design synthesis, finite element analysis, time stepped system simulation and iron loss estimation techniques are demonstrated. The construction of a prototype motor is described and the feasibility of fabricating the multi-pole rotor assembly, using capacitor-discharge magnetisation techniques, is addressed. Finally, the test results of the motor drive are presented.