Sensorless Control of Permanent Magnet Synchronous Motor with Flux Weakening Operation for Washing Machine Application

Modern domestic appliances such as Washing Machine are designed in consideration with energy saving measures. This involves improving the performance and efficiency of the complete drive system. Permanent Magnet Synchronous Motor's (PMSMs) in conjunction with Vector Control Strategy are chosen as driving system for such high efficient and high performance smooth torque control applications. Employing advanced vector control technique is challenging in terms of cost and reliability as it requires sensors for detecting rotor speed and rotor position for its effective functioning. In this paper, a Sensorless Control of PMSM based on Model Reference Adaptive theory is applied to Washing Machine home appliance. Washing machine application requires speeds above base speeds when it is operating in Spin Dry cycle and requires below base speeds when it is operating in Wash cycle. To obtain spin dry cycle flux weakening operation is required whereas wash Cycle is obtained by employing Maximum Torque per Ampere (MTPA) as MTPA ensures high efficiency with less copper losses. Model Reference Adaptive System (MRAS) based on Stator current controller is used as rotor position estimation algorithm which is one of the simpler and accurate estimation technique. Results demonstrate the effectiveness of the sensorless PMSM compared to controller with sensors in both Wash Cycle and Spin Dry cycle of washing operations.