# An Investigation of Parameter Dimension Reduction Optimization of PMA-Synrm
## 3 Parameter Dimension Reduction Optimization Design of the PMA-Synrm
### Optimization Results and Finite Element Verification of PMA-Synrm  
The magnetic cloud diagram of the motor load before and after the optimization of the permanent magnet-assisted synchronous reluctance motor is shown in Figure 13. It can be seen from the diagram that the magnetic saturation degree of the multi-layer magnetic conductive layer on the rotor of the motor before optimization is high, and there are several stator teeth close to saturation. However, the degree of magnetic saturation on the stator and rotor of the optimized motor is greatly reduced. Figure 14 shows the no-load back EMF waveform and harmonic distribution before and after optimization of the permanent magnet-assisted synchronous reluctance motor. It can be seen from Figure 14a that the effective value of the no-load back EMF of the motor before optimization is slightly higher than that after optimization, but the no-load back EMF waveform of the optimized motor is more sinusoidal. In addition, the harmonics of \begin{table}
\begin{tabular}{c c} \hline \hline
**Symbol** & **Optimal Results** \\ \hline \(w_{d}\) (mm) & 4.70 \\ \(h_{d}\) (mm) & 2.82 \\ \(w_{q}\) (mm) & 2.94 \\ \(h_{q}\) (mm) & 4.78 \\ Rid (mm) & 1.0 \\ L1 (mm) & 38 \\ L2 (mm) & 38 \\ L3 (mm) & 34 \\ L4 (mm) & 28 \\ L5 (mm) & 21.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Optimization results of permanent magnet-assisted synchronous reluctance motor. Figure 13: Magnetic density cloud diagram of motor load before and after optimization. (**a**) Initial. (**b**) Optimal. the optimized motor are mainly 15 and 17 times, and the harmonic content is much less than that before optimization, as shown in Figure 14b. Figure 15 shows the no-load radial air gap flux density waveform and harmonic distribution before and after optimization of the permanent magnet-assisted synchronous reluctance motor. It can be seen from Figure 15a that the no-load back EMF of the optimized motor is slightly lower than that before optimization, but the optimized air gap flux density waveform is more sinusoidal. As shown in Figure 15b, the no-load air gap harmonics of the optimized motor are mainly 17 and 19 harmonics, and the harmonic content and the amplitude of the magnetic isolation harmonics are small. Figure 16 shows the torque characteristics and electromagnetic performance of the permanent magnet-assisted synchronous reluctance motor before and after optimization. As shown in Figure 16a, the average torque of the optimized motor is 49.7 Nm, which is 0.5 Nm lower than that before optimization. However, the optimized torque ripple is only 4.8%, which is 10.8% lower than that before optimization. It can be seen from Figure 16b that the efficiency of the optimized motor is 94.1%, which is 0.6% higher than that before optimization. Because the optimized no-load back EMF decreases slightly, the optimized power factor is slightly smaller than that before optimization. Figure 14: The no-load back-EMF waveform and harmonic distribution of the PMA-Synrm before and after optimization. (**a**) No-load back EMF waveform. (**b**) No-load back EMF harmonic distribution. Figure 15: The no-load radial air gap flux density waveform and harmonic distribution of the permanent magnet-assisted synchronous reluctance motor before and after optimization. (**a**) No-load radial air gap flux density waveform. (**b**) No-load radial air gap flux density waveform harmonic distribution. The temperature simulation of the motor is carried out by using the thermal module of Motor-CAD. The motor uses the same heat dissipation method as the asynchronous motor; that is, the casing has a heat dissipation fin, the shaft sleeve fan, and the fairing is used to distribute the air volume to take away the heat of the motor.