DC/DC pre-regulator for input current ripple reduction and efficiency improvement

The cascade connection of a low-ripple voltage doubler pre-regulator and a classical boost converter regulator is proposed to improve the efficiency of the full system due to the reduction in average currents of all boost converters and the smaller duty cycle required for the conventional boost regulator. The pre-regulator inherent low input current ripple, which operates at a 50% duty cycle in complementary interleaving mode, makes the system suitable for current ripple sensitive power generators such as fuel cells or photovoltaic modules. In addition, the proposed solution increases the maximum voltage conversion ratio achievable, and the independent control schemes of the pre-regulator and the boost stage do not increase the control complexity of the system. (C) 2011 Elsevier B.V. All rights reserved.