A dv / dt Output Filter for Mitigating Motor Terminal Overvoltage in SiC-Based Motor Drive Systems

The Silicon carbide (SiC) MOSFET, as a prominent wide bandgap device, is extensively used in motor drive systems due to its high-speed switching characteristic. However, higher dv/dtwill cause overvoltage at the motor terminals, accelerate the aging of windings and bearings, seriously threaten the insulation of motor windings, and shorten the service life of the motor. To address the critical challenge, this paper proposes a novel third-orderLCRLdv/dtfilter topology, which introduces parallel inductance to improve the flexibility of cable matching and shunts damping resistors to reduce damping loss, thereby significantly reducing the volume and cost of the heat sink. A parameter design method suitable for high-order filters and a multi-dimensional design optimization strategy based on the optimal loss model are proposed to simultaneously find the best solution to minimize motor terminal overvoltage and total system loss, providing theoretical guidance for the application of high-order dv/dtfilters. A series of experimental results demonstrate that the motor terminal overvoltage, damping loss, and volume of the proposed filter are reduced by 81.5%, 43.7%, and 33.3%, respectively, compared with the conventionalLCRfilter, which improves motor reliability in high-speed switching applications without compromising system efficiency.