**3. Experimental results and discussions**

We used an 18-poled 8000 rpm 7 kVA PMSG in this study. The design is done using Maxwell. **Table 2** lists the design parameters. The PMSG's structure is also shown in **Figure 5**. The rated power factor of the PMSG is 1.0. All of the winding material in the Maxwell design is standard copper. Lamination is done with Si-Fe. Finally, the insulation material H-Class is chosen.

The goal of the first stage is to use regression modeling to find the mathematical relationship between the factors (magnet thickness (*X1*), offset (*X2*), and embrace (*X3*)) and the responses (efficiency (%), rated torque (N.m), air-gap flux density (Tesla), armature current density (A/mm<sup>2</sup> ), armature thermal load (A2 /mm<sup>3</sup> )) by using regression modeling. "RSM face-centered design" is used to create an experiment to complete this phase. The factor levels for this experimental design are shown in **Table 3**. **Figure 6** shows a graphical representation of the experimental design. The level-2 for embrace in a standard face-centered design is 0.8%. However, due to the restrictions of the serially configured production line, we used 0.8% in the experimental design instead of 0.75%.

**Name Value Unit Part Description** Machine type N/A — — 3-phase adjust speed PMSG Inner dia. 100 Mm Stator Gap side core diameter Outer dia. 160 Mm Stator Yoke side core diameter Length 50 Mm Stator Length of the core Skew width 1 Units Stator Slot range number Slot type 3 N/A Stator Circular Slots 54 Units Stator Number of slots Bs1 2.7 Mm Stator Tooth width Hs0 0.5 Mm Stator Slot opening height Hs2 23 Mm Stator Slot height Inner dia. 30 Mm Rotor Gap side core diameter Outer dia. 99 Mm Rotor Yoke side core diameter Length 50 Mm Rotor Length of the core Poles 18 — Rotor Number of poles Magnet NdFe35 — Rotor Magnet type

According to the graphical representation of experimental design that is presented in **Figure 6**, it can be clearly indicated that there are 15 experimental runs for three factors. However, no simulation could be made in Ansys Maxwell for the (1, +1, +1)

#### **Table 2.**

*Design parameters of 18-poled 8000 rpm 7 kVA PMSG.*

*Design Optimization of 18-Poled High-Speed Permanent Magnet Synchronous Generator DOI: http://dx.doi.org/10.5772/intechopen.106987*

#### **Figure 5.** *Structure of the PMSG.*

