Magnetic Shield Design Between Interior Permanent Magnet Synchronous Motor and Sensor for Hybrid Electric Vehicle

This paper shows a design and analysis method of magnetic shield structure between a position sensor and an interior permanent magnet synchronous motor (IPMSM) for hybrid electric vehicle (HEV). For a vector control algorithm and high reliability of traction system of HEV, a resolver is usually adopted as a position sensor of IPMSM instead of an encoder. However, the design of IPMSM for HEV requires characteristics such as high torque density, compact size, and low current density in windings. As a result, the resolver using the induced voltage of resolver winding by magnetic flux is likely to be influenced by leakage magnetic flux of IPMSM. Therefore, appropriate magnetic shield design is needed to decrease the penetration of leakage magnetic flux into resolver. We designed and analyzed a magnetic shield structure by using 3D FEM in order to calculate the leakage magnetic flux influence into resolver more exactly. Finally, experiment results by using both vector inverter and IPMSM show the validity of proposed magnetic shield design.