Abstract:
The growth of brushless DC (BLDC) motor drives in industrial and residential
applications emphasizes the need to effectively understand electromagnetic
interference (EMI). This critical concern can significantly impact system
performance and electromagnetic compatibility (EMC) requirements. This thesis
addresses the nuanced challenges EMI poses in the context of a three-phase Silicon
Carbide (SiC) fed BLdc motor drive, leveraging the advantages of trapezoidal back
electromotive force (EMF) profiles.
While BLDCmotorsoffersuperior attributes, including high torque-to-weight ratios,
enhanced efficiency, and reduced acoustic noise, the integration of wide bandgap
(WBG) power devices, such as SiC and Gallium Nitride (GaN), further elevates
power density and efficiency. Despite the extensive discourse on EMI issues in
induction motor drives, the research has paid limited attention to EMI challenges
specific to trapezoidal flux BLdc motors. This thesis fills this gap by comprehensively
analyzing common-mode (CM) noise in SiC-fed BLDC motor drives. Additionally,
the study investigates the influence of various pulse-width modulation (PWM)
schemes on CM noise and assesses their impact on the sizing requirements of
CM chokes. Furthermore, the thesis explores the design and implementation of
DC-side single-stage and two-stage EMI filters for motor drives. A novel approach
is employed to reduce the footprint of the EMI filter printed circuit board (PCB), and
minimize the volume of the filter enclosure of the EMI filter through an integrated
magnetic methodology.
In conclusion, this research contributes valuable insights into the intricate realm of
EMI management in SiC-fed trapezoidal back EMF BLDC motor drives, offering
practical solutions for enhancing EMC compliance while maximizing the advantages
of WBG power devices in motor drive applications
