Comparison between position-encoder and position-sensorless vector control of High Speed PMSM with Flux Weakening Operation

Domestic Appliances such as washing machine requires higher speeds during spin dry cycle and is usually 2 to 3 times of rated speeds. Even traction applications require wide range of speed control. To achieve speeds greater than rated speeds, Flux Weakening is employed. Due to load perturbations and due to higher speeds, appliance such as Washing machine is subjected to excessive vibrations and thereby affecting the dynamic performance of system. Effective Control approach such as Field Oriented Control is essential for designing a high performance drive system. Cost and reliability concerns should be taken into consideration while employing such control techniques as it requires sensors for detecting rotor speed and position information for its effective functioning. In this paper, a Sensorless Field Oriented Control of Permanent Magnet Synchronous Motor (PMSM) with Flux Weakening is evaluated. Model Reference Adaptive System (MRAS) based on stator current controller is used as position-sensorless estimation algorithm and a comparison is performed between controller with sensors (position-encoder) and sensorless controller. Results have demonstrated the feasibility and effectiveness of sensorless control compared to controller with sensors.