Starting Characteristic Analysis And Optimization Design For Line Start Permanent Magnet Synchronous Motor

About 45% of the worlds electric energy is consumed by motors,under the “double carbon”goal,improving the efficiency of motors is an important measure to effectively reduce energy consumption and emissions.Compared with the induction motor,the line start permanent magnet synchronous motor(LSPMSM)have permanent magnets in their rotor cores,and rely on the asynchronous torque generated by the squirrel-cage rotor windings to start.It has the advantages of small size,light weight,high efficiency and high power factor in a wide load range.However,rare earth permanent magnets are non-renewable resources,and their production costs are too high.Compared with LSPMSM,the reluctance assisted line start permanent magnet synchronous motor(RALSPMSM)can effectively reduce the use of permanent magnet materials and costs.This paper firstly introduces the status of domestic and international research on line-start permanent magnet synchronous motor and permanent magnet-assisted synchronous reluctance motor,and analyzes the working mechanism,transient process and steady-state process torque characteristics of reluctance-assisted line-start permanent magnet synchronous motor.Two reluctance-assisted rotor topology optimization methods are proposed for line-start permanent magnet synchronous motors.For the reluctance-assisted line-start single-level PM synchronous motor,the reluctance-assisted starting performance is enhanced by reluctance-assisted,and the amount of permanent magnets is saved and the cost is reduced;the rotor-assisted slot design improves the motor efficiency.For the reluctance-assisted line-start double-layer PM synchronous motor,the motor efficiency is improved by optimizing the reluctance-assisted position with the same amount of permanent magnets,and the starting characteristics are enhanced by combining two sets of rotor slots.Based on the finite element method,an Ansys Maxwell simulation model is constructed and its related characteristics are analyzed.The data show that: for the reluctance-assisted single-stage line-start permanent magnet synchronous motor,the amount of permanent magnets is effectively saved and the starting performance is improved compared with the line-start permanent magnet synchronous motor;for the reluctance-assisted double-stage line-start permanent magnet synchronous motor,with the same amount of permanent magnets,the reluctance-assisted position optimization reduces the eddy current loss of the motor and improves the efficiency;the combination of two sets of rotor slots reduces the competition between permanent magnets and rotor slots and enhances the starting performance of the motor.