Analysis of Shaft Voltage Characteristics According to Rotor Overhang of Wound-Field Rotor Synchronous Motor for Electric Vehicle

This study analyzes the characteristics of shaft voltage due to rotor overhang in a wound-field rotor synchronous motor(WRSM) for electric vehicle. Recently, WRSM have gained significant attention as alternatives to permanent magnet motors. However, they exhibit disadvantages in torque density compared to permanent magnet motors, since they do not utilize permanent magnets. To solve this drawback, rotor overhang is commonly applied, but this can adversely affect voltage insulation due to end leakage flux. To verify this, models without and with rotor overhang are separately modeled to analyze shaft voltage characteristics. The results confirm the impact of rotor overhang on shaft voltage in the design of WRSM.