Modeling and Analysis of Assembly Faults of a Dual-Stator Low-Speed High-Torque Permanent Magnet Drive Machine

Dual-stator permanent magnet machines are widely used in the low-speed high-torque applications, benefiting from the advantages of high efficiency and high torque density. For the dual-stator machine, a key performance indicator is whether the reasonable power allocation between the inner and outer machines can be achieved during the operation. The back EMFs of machines will be changed because of assembly faults, which may affect the power allocation. In this paper, the modeling and analysis of assembly faults are carried out based on a dual-stator low-speed high-torque permanent magnet drive machine (DLHPMDM). The influence of inaccurate positioning of inner and outer stators is more accurately analyzed through a modeling method which combines the advantages of voltage excitations and current excitations in the finite element analysis (FEA). For the axial deviation fault of stators, the 3D FEA is replaced by a 2D modeling method to analyze the influence on the power allocation, which can save the time required for the simulation. Then a test method is proposed to evaluate the assembly accuracy, and corresponding measures are implemented to reduce the influence of assembly faults. Finally, a DLHPMDM prototype is assembled and tested to verify the above analysis.