Very-low-speed variable-structure control of sensorless Axial Flux Permanent Magnet Synchronous Motor Using an Advanced Rotor Flux Concept - TI Journals

axial flux synchronous motor extended rotor flux Fuzzy PI controller speed Estimation In this Paper, several essential and important improvements of the sensor less direct torque control (DTC) strategy for interior permanent magnet (IPM) synchronous motor drive are presented. The studies comprising of analytical, modeling implementation clearly indicate the potential of a highperformance direct torque controlled AFPM synchronous motor drive without a mechanical encoder .In this study, speed sensor less fuzzy control of an Axial Flux Permanent Magnet Synchronous Motor (AFPMSM) using an advanced flux concept at very low speeds (close to zero) is investigated. Due to higher torque in low speeds and higher efficiency, Axial Flux Motors (AFMs) have more applications than Radial Flux Motors (RFMs) including spacecraft, electric vehicles, direct driven screw propeller, blowers, etc. High prices and the need for maintenance that reduces the system reliability, limit the use of sensors in drive systems. For this reason, several methods have been proposed to estimate the motor speed and position. The method presented in this paper, uses extended rotor flux concept to estimate the motor speed. From mathematical point of view, this concept converts an Interior Permanent Magnet (IPM) motor model to a Surface-mounted Permanent Magnet (SPM) one that simplifies the computations. Furthermore, in this paper a fuzzy PI control has been used that offers better results than the classic PI control.