Flexible Load-Dependent Soft-Start Method for Digital PID Control DC-DC Converter in 380Vdc System

Hidenori MARUTA  Tsutomu SAKAI  Suguru SAGARA  Yuichiro SHIBATA  Keiichi HIROSE  Fujio KUROKAWA  

Publication
IEICE TRANSACTIONS on Communications   Vol.E100-B   No.4   pp.518-528
Publication Date: 2017/04/01
Online ISSN: 1745-1345
Type of Manuscript: PAPER
Category: Energy in Electronics Communications
Keyword: 
dc-dc converter,  soft-start,  380 Vdc,  digital control,  

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Summary: 
The purpose of this paper is to propose a flexible load-dependent digital soft-start control method for dc-dc converters in a 380Vdc system. The soft-start operation is needed to prevent negative effects such as large inrush current and output overshoot to a power supply in the start-up process of dc-dc converters. In the conventional soft-start operation, a dc-dc converter has a very slow start-up to deal with the light load condition. Therefore, it always takes a long time in any load condition to start up a power supply and obtain the desired output. In the proposed soft-start control method, the speed of the start-up process is flexibly controlled depending on the load condition. To obtain the optimal speed for any load condition, the speed of the soft-start is determined from a approximated function of load current, which is estimated from experiment results in advance. The proposed soft-start control method is evaluated both in simulations and experiments. From results, it is confirmed that the proposed method has superior soft-start characteristics compared to the conventional one.