Digital load-dependent soft-start method of DC-DC converter for energy management system

This paper presents a new digital load-dependent soft-start method of dc-dc converter for energy management system. The soft-start operation is used to prevent negative effects for a power supply. In the conventional soft-start operation, the dc-dc converter must start up very slowly to deal with the worst load condition. It takes long time to start up a power supply. The proposed digital control method is constructed as the digital current-mode control dc-dc converter used in the higher voltage direct current (380V HVDC) system. The speed of the soft-start operation should be set up depending to the load conditions. In the proposed digital control method, the fastest speed of the soft-start is determined using the approximated linear function of output current which is obtained from the experiment results in advance. The proposed control method has the superior soft-start characteristics of the output voltage. As a result, the convergence time of the output voltage is improved in the soft-start operation.