Industry is the largest user of energy worldwide, with industrial motors consuming most of the total energy. Therefore, the goal of improving efficiency and reducing power loss caused by electric motors is of great significance in industrial production systems and energy systems. Line-start synchronous motors (LSPMSM) have the highest potential to replace conventional induction motors in providing traction due to their much higher efficiency compared to induction motors. This article studies one of the most demanding operating conditions of a direct-start synchronous machine with a W-shaped magnet structure. The finite element method is used as a tool to evaluate the phenomenon of demagnetization of this motor. Research results on different types of magnets with W-shape structures and their corresponding demagnetization effects will be presented.