Static and Dynamic Characteristics of DC-DC Converter Using a Digital Filter

Fujio KUROKAWA  Masashi OKAMATSU  

Publication
IEICE TRANSACTIONS on Communications   Vol.E92-B   No.3   pp.998-1003
Publication Date: 2009/03/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E92.B.998
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Energy in Electronics Communications
Keyword: 
digital control,  PID control,  FIR filter,  IIR filter,  

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Summary: 
This paper presents the regulation and dynamic characteristics of the dc-dc converter with digital PID control, the minimum phase FIR filter or the IIR filter, and then the design criterion to improve the dynamic characteristics is discussed. As a result, it is clarified that the DC-DC converter using the IIR filter method has superior performance characteristics. The regulation range is within 1.3%, the undershoot against the step change of the load is less than 2% and the transient time is less than 0.4 ms with the IIR filter method. In this case, the switching frequency is 100 kHz and the step change of the load R is from 50 Ω to 10 Ω . Further, the superior characteristics are obtained when the first gain, the second gain and the second cut-off frequency are relatively large, and the first cut-off frequency and the passing frequency are relatively low. Moreover, it is important that the gain strongly decreases at the second cut-off frequency because the upper band pass frequency range must be always less than half of the sampling frequency based on the sampling theory.