This paper presents the study and evaluation of a medium-voltage grid-tied cascaded H-bridge (CHB) three-phase inverter for battery energy storage systems using SiC devices as an enabling technology. The high breakdown voltage capability of SiC devices provide the advantage to significantly minimize the complexity of the CHB multilevel converter, with less power loss compared to when Silicon (Si) devices are used. The topology in this study has been selected based on high voltage SiC devices. In order to reach 13.8 kV, a nine-level CHB is needed when using 6.5 kV SiC MOSFETs. However, if 10 kV SiC MOSFETs are used, only five-levels of the CHB are required. The controls were developed, simulated and verified through an experimental prototype. The results from the scaled-down prototype proved the controls and the verification of the performance of five-level CHB three-phase inverter. For the system reliability, both open-loop and short-circuit faults are analyzed.
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This content will become publicly available on March 1, 2027
Design and Validation of a 100 kHz Inner-Paralleled Si+SiC Hybrid Multilevel Converter for Medium-Voltage Electric Traction Drives
In this paper, a novel medium-voltage (MV) hybrid multilevel inverter with an inner-paralleled (IP) half-bridge (HB) is designed and developed for electric traction drives with a 3-kV dc bus. Within this proposed hybrid configuration, each phase consists of an active-neutral-point-clamped (ANPC) three-level (3-L) cell that adopts 3.3-kV silicon (Si) IGBTs operating at a fundamental frequency, while the IP cell using a custom 3.3-kV H-bridge silicon carbide (SiC) MOSFET operates at a frequency of 50 kHz. With interleaving through line inductors, the output apparent switching frequency has been doubled, e.g., 100 kHz. The comprehensive design and demonstration of the full-scale prototype are intro-duced, including low-inductance laminated busbar architecture optimization, H-bridge power electronics building block (PEBB) design, modular system integration, and proprietary modulation and controls. Extensive simulation and experimental results are presented to validate the overall performance of the studied proto-type systems in steady and dynamic states. The findings show that in contrast to existing all-Si or SiC-based 3-L and five-level (5-L) ANPC, the proposed new 5-L Si+SiC converter is characterized by higher power efficiency and density, better harmonics properties, higher dc bus voltage, lower dv/dt, and build cost, which provides a promising electrified solution for MV traction drives in the trans-portation sector.
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- Award ID(s):
- 1939144
- PAR ID:
- 10677048
- Publisher / Repository:
- IEEE
- Date Published:
- Journal Name:
- IEEE transactions on industry applications
- Volume:
- 62
- Issue:
- 2
- ISSN:
- 0093-9994
- Page Range / eLocation ID:
- 2735
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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