水下航行器高速电机具有高速、大功率、多挡位可调等特点，为了减小水下航行器有限空间内的高速无刷直流电机(BLDCM)转矩脉动，分析了水下航行器高速电机对高开关频率的需求，对BLDCM转矩脉动进行了数学分析，得到BLDCM的转矩脉动与开关频率及占空比等的关系。利用SiC MOSFET开关频率高的特点来提高逆变器开关频率，从而降低高速电机转矩脉动，同时SiC MOSFET又有开关损耗小的优点，与使用绝缘栅双极型晶体管(IGBT)相比，SiC MOSFET在提高开关频率的同时可以减少开关损耗。最后通过仿真和试验验证了SiC MOSFET在较高开关频率时对高速BLDCM转矩脉动抑制的效果，为宽禁带半导体器件在水下航行器高速BLDCM的应用提供参考。

The high-speed motor of underwater vehicle has the characteristics of high-speed, high-power and multi-gear adjustable, etc. In order to reduce the torque ripple of high-speed brushless direct current motor (BLDCM) in the limited space of underwater vehicle, the demand for high switching frequency of high-speed motor of underwater vehicle is analyzed. The torque ripple of BLDCM is analyzed mathematically, so the relationship between torque ripple and switching frequency and duty ratio of BLDCM is obtained. The high switching frequency of SiC MOSFET is used to improve the switching frequency of inverter and reduce the torque ripple of highspeed motor. At the same time, SiC MOSFET has the advantage of low switching loss. Therefore, compared with insulated gate bipolar transistor (IGBT), SiC MOSFET can reduce the system efficiency caused by switching loss while improving the switching frequency. Finally，the effect of SiC MOSFET on torque ripple suppression of highspeed BLDCM at higher switching frequency is verified by simulation and experiment, which provides a reference for the application of widebandgap semiconductor devices in highspeed BLDCM of underwater vehicles.