Optimized design and research of direct-drive permanent magnet synchronous motor for hydra pulper

This paper presents the design of a direct-drive permanent magnet synchronous motor specifi-cally tailored for the transmission of a hydra pulper, boasting a rated power of 350 kW and a rated speed of 230r/min. A finite element model of the direct-drive permanent magnet synchronous motor is established to comprehensively analyze various performance parameters, encompassing magnetic characteristics, magnetic circuitry, reverse electromotive force, and more. Employing the coercive force method in conjunction with the magnetic density method, the demagnetization propensity of the permanent magnet under extreme operating conditions is evaluated and analyzed, facilitating the rapid identification of boundary size conditions for the permanent magnet and thereby mitigating overall motor costs. Furthermore, a genetic algorithm is employed to optimize the structural parameters of the direct-drive permanent magnet synchronous motor, enhancing comprehensive performance parameters such as power, efficiency, power factor, torque ripple, among others, while ensuring the motor remains demagnetization-free.