# An Investigation of Parameter Dimension Reduction Optimization of PMA-Synrm
## 1 Introduction  
A permanent magnet-assisted synchronous reluctance motor combines the characteristics of a synchronous reluctance motor and a permanent magnet synchronous motor [1]. It has higher power density and a wider speed range, and the performance of motor power factor and efficiency is second only to permanent magnet synchronous motor [2, 3]. However, the manufacturing cost of a permanent magnet-assisted reluctance motor is much lower than that of a permanent magnet synchronous motor [4, 5] because it only uses ferrite to assist magnetism. Therefore, a permanent magnet-assisted synchronous reluctance motor has become an important research object for the development of motor to \"no rare earth, less rare earth\". At present, a permanent magnet-assisted synchronous reluctance motor has become a research hotspot and has been applied in household appliances, low-voltage industry, electric vehicles, and low-speed high-torque fields. At present, the research on a permanent magnet-assisted synchronous reluctance motor is mainly aimed at the analysis and design of rotor structure and the optimization design of the motor. In terms of rotor structure, the effects of the number of rotor magnetic barrier layers, the position and shape of the rotor magnetic barrier, and the proportion of rotormagnetic barrier on the main performance of a permanent magnet-assisted synchronous reluctance motor are studied. The basic design rules of a permanent magnet-assisted synchronous reluctance motor are summarized [6]. In [7, 8], the influence of different magnetic saturation degrees on the performance of a synchronous reluctance motor is studied. In addition, the electromagnetic performance of the synchronous reluctance motor before and after inserting the permanent magnet is compared and analyzed. The anti-demagnetization research of a permanent magnet-assisted synchronous reluctance motor is also a hot spot. Refs. [9, 10] proposed a new rotor structure. Several bypass ribs are opened in the rotor magnetic barrier to provide a path for the demagnetization of the armature winding. Finally, the effect of reducing the output torque ripple of the motor and improving the anti-demagnetization ability of the motor is achieved. There are also many studies on ferrite design in a permanent magnet-assisted synchronous reluctance motor. These studies mainly focus on the influence of permanent magnet placement position, permanent magnet layer number, and permanent magnet insertion position on the electromagnetic performance of a permanent magnet-assisted synchronous reluctance motor [11, 12]. In addition, many scholars have adopted an asymmetric rotor structure to improve the performance of a permanent magnet-assisted synchronous reluctance motor [13, 14]. In general, the current research on the rotor structure of a permanent magnet-assisted synchronous reluctance motor is more detailed, which has great guiding significance for the design of such motors. The research on the optimization design of a permanent magnet-assisted synchronous reluctance motor is also gradually deepened. Ref. [15] proposed to optimize the permanent magnet-assisted synchronous reluctance motor by establishing a simplified analytical model. The analytical model can quickly calculate the optimal end angle of the magnetic isolation bridge to achieve the purpose of reducing the torque ripple of the motor. However, only the influence of the end angle of the magnetic bridge on the output torque ripple is considered. As shown in ref. [16], through a series of mathematical formulas commonly used in motors, the calculation formula of output torque is derived, and various parameters affecting the calculation formula of torque are constrained. Then, the torque of the synchronous reluctance motor is maximized by a genetic algorithm considering a set of mechanical, thermal, and efficiency constraints. In the optimization process, the selected optimization parameters do not involve the structural design parameters of the synchronous reluctance motor rotor. Ref.