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Electromagnetic Interference (EMI) Mitigation and Containment in SiC-Based Modular UPS for Industrial Applications
07/01/2016TYPE: PROJECT
Document Tags: 2016, 2017
Sponsors: Department of Energy through PowerAmerica Institute
ABSTRACT
ABB Corporate Research and CPES jointly pursued the efficiency and power density improvement of industrial uninterruptible power supply (UPS) units. Within a broader scope, ABB sought to adopt SiC MOSFET/ Schottky barrier diode power module technology to replace existing Si-insulated, gate bipolar transistors solutions, while CPES developed an electromagnetic interference (EMI) mitigation and containment strategy. Specifically, CPES conducted a topology selection for the UPS module, which resulted in a three-level, back-to-back ac-ac converter configuration, with an additional three-level dc-dc converter acting as battery charger using 1.2 kV three-level all-SiC power modules from Microsemi. With the use of CPES-developed modulation and control schemes, the EMI emissions of the unit have been significantly reduced, effectively mitigating this type of interference and ensuring the safe operation of the UPS. A key aspect successfully demonstrated in the EMI suppression scheme was the importance in protecting the control circuitry and auxiliary power network of the unit to ensure its operational integrity. Further, the project also developed a three-port common mode voltage model of the UPS, which was necessary to evaluate the impact of the two three-phase ac-dc stages and the dc-dc battery charger sharing the same dc bus. From this model, a propitious control and CM voltage mitigation strategy was developed. The UPS module and EMI containment and suppression strategies were fully demonstrated in the summer of 2017.
