Sigma-Delta Modulation of Multi-Phase High Frequency Converters


A power conversion control architecture is proposed that merges advanced digital modulation techniques, high frequency resonant converters, and multi-phase converters. If a converter's switching frequency is high enough, the converter may be turned on and off quickly to modulate power flow. The proposed system is composed of several high frequency converters connected in parallel, only a few of which are active at a given time to regulate the output voltage. The number of active converters is determined through a sigma-delta modulation process. The specific converter enable signals are generated by a balancing algorithm that ensures approximately equal effective duty ratio and switching frequency for all phases. An output voltage regulator, here implemented as a PI loop, completes the system. The method has been simulated for an eight-phase closed-loop system. Experimental results are shown for a four-phase open-loop system with an external command that corresponds to the effective duty ratio of the power converters.

Meeting Name

25th Annual IEEE Applied Power Electronics Conference and Exposition (2010: Feb. 21-25, Palm Springs, CA)


Electrical and Computer Engineering


National Science Foundation (U.S.)


This work was supported in part by the U.S. National Science Foundation under grant #0812121.

Keywords and Phrases

Active Converters; Balancing Algorithms; Control Architecture; Digital Modulation Techniques; Duty Ratios; Four-Phase; High Frequency Converter; High Frequency Resonant Converter; Multiphase Converters; Open Loop Systems; Output Voltages; Power Conversion; Power Flows; Sigma Delta Modulation; Electric Potential; Electric Power Supplies To Apparatus; Frequency Converters; Modulation; Modulators; Power Electronics; Switching Frequency; Voltage Regulators; Delta Sigma Modulation

International Standard Book Number (ISBN)


International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version


File Type





© 2010 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Feb 2010