Position linearisation scheme for permanent magnet synchronous motor drive of washing machine using low‐resolution hall sensors

Abstract

Variable speed systems have been widely applied to home appliances. One of the applications is vector control scheme of a washing machine using low‐resolution hall sensors. Vector controller with binary‐type hall sensors is cost effective. However, due to electrical and mechanical non‐uniformity related to hall sensors, the position obtained by hall sensors does not change linearly, and resultant bumps in the position information degrade control performance. To solve this problem, a new position observer that generates linearly changing position signal is proposed. The proposed scheme removes necessity of knowing mechanical parameters and additional calculation process by utilising a Kalman filter for speed detection. The feasibility and effectiveness of the proposed algorithm are verified through experimental results carried out with a washing machine.