Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Analytical Expression for DC Link Capacitor Current in a Cascaded H-Bridge Multi-Level Active Front-End Converter

Conference · · 2021 IEEE Applied Power Electronics Conference and Exposition (APEC)

Medium-voltage grid-tied systems often use a cascaded H-bridge multi-level active front-end. In this converter, dc link bus capacitors play an important role in stabilizing the converter and enabling both active and reactive power injections. The present work provides analytical expressions for the capacitor current, which are essential for optimizing system design (especially capacitor size vs. lifetime). Then, the expression is incorporated into the grid connected bidirectional power system model. Consequently, this work contributes to the guiding principles to choose accurate dc link capacitor ratings against grid-side power delivery requirements. The analytical results have been validated with detailed simulations and hardware results.

Research Organization:
Missouri University of Science and Technology
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Sustainable Transportation. Vehicle Technologies Office (VTO)
DOE Contract Number:
EE0008449
OSTI ID:
1991839
Journal Information:
2021 IEEE Applied Power Electronics Conference and Exposition (APEC), Conference: 2021 IEEE Applied Power Electronics Conference and Exposition (APEC)
Country of Publication:
United States
Language:
English

References (11)

Analytical Determination of the Capacitor Voltage Balancing Dynamics for Three-Phase Flying Capacitor Converters journal July 2009
Determination of DC link harmonics in dual active bridge DC-DC converters using frequency domain analysis conference May 2016
Analysis of the DC-Link Capacitor Current of Power Cells in Cascaded H-Bridge Inverters for High-Voltage Drives journal December 2014
The DC-link capacitor current in pulsed single-phase H-bridge inverters conference January 2005
Reliability of Capacitors for DC-Link Applications in Power Electronic Converters—An Overview journal September 2014
DC link harmonics of three phase voltage source converters influenced by the pulse width modulation strategy-an analysis conference January 2005
A method for hotspot temperature estimation of aluminum electrolytic capacitors conference October 2017
A General Analytical Method for Calculating Inverter DC-Link Current Harmonics journal January 2009
A comprehensive analysis of DC-link current for single phase H-bridge inverter under harmonic output currents conference October 2017
Analytical calculation of the RMS current stress on the DC link capacitor of voltage DC link PWM converter systems conference January 1999
The Aging Process in Electrical Insulation: A Tutorial Summary journal September 1972