Design and Performance Analysis of Permanent Magnet Claw Pole Machine with Hybrid Cores

Abstract

Permanent magnet claw pole machine (PMCPM) is a special kind of transverse flux permanent magnet machine. Compared with other electrical machines, it has the advantages of high torque density and high efficiency for high speed operation. However, because of its complex irregular structure, the manufacturing process using silicon sheets is complicated. Soft magnetic composite material (SMC) is manufactured by powder metallurgy technology, which can produce various shapes of stator core structures, so it is easier to produce various irregular shapes of the stator core. However, the raw SMC material is relatively expensive, and the mechanical strength of SMC is weak. In this paper, a PMCPM with hybrid cores is proposed. With the adoption of hybrid silicon sheet -SMC cores and amorphous alloy -SMC cores, the torque ability of PMCPM can be improved greatly and it can have higher efficiency for more wide operation frequency. Meanwhile, its mechanical strength has been improved and it can be designed for high torque direct drive applications as it is a modular machine. Furthermore, three methods are proposed to reduce the additional eddy current loss which resulted from the employment of hybrid cores in PMCPM.

State-of-the-Art Lightweight Implementation Methods in Electrical Machines

“…Due to the appli-cation of SMC cores, a 3D magnetic circuit can be achieved, thus resulting in relatively high torque capability, as presented in Figure 5b. Furthermore, a PM claw pole machine with hybrid cores containing steel sheets and SMC cores is proposed in [43], aiming to take advantage of the magnetic properties of SMC materials while enhancing mechanical strength, as depicted in Figure 5c. The results indicate both greatly improved torque ability and higher efficiency for a wide operation frequency range.…”

“…(1) Motor weight reduction: 9%~10% [35,36] (2) Slot fill factor: 75%~83.8% [35][36][37] (1) High resistivity (2) The impact on the reliability of the wire insulation layer Soft magnetic composites [41][42][43] High purity and compressibility of iron powder…”

“…(1) Power per unit volume: 526~673 kW/m 3 [41] (2) Efficient: 78%~88% [41][42][43] (1) Low permeability and high hysteresis loss (2) Low mechanical strength Superconducting materials [46][47][48] YBCO, REBCO…”