Input Voltage Sharing Control Scheme for Input Series and Output Parallel Connected DC–DC Converters Based on Peak Current Control

Abstract

It is difficult for a single converter to handle the high voltages involved in dc–dc conversion with a high-voltage input bus. Input-series–output-parallel (ISOP) technology can be used to solve this problem. In this paper, an input voltage sharing control scheme based on peak current (IVSPC) control to guarantee power balance between the modules of the ISOP system is studied. Owing to the peak current control, the output voltage of the system has a good ability to suppress input bus perturbations, and it exhibits good dynamic characteristics even when the input voltage changes significantly with a high slope. The IVSPC control method has two kinds of loops: a common output voltage regulation (OVR) loop and individual input voltage sharing (IVS) loops. The OVR loop provides the same current reference component for all modules, whereas the IVS loops provide different components. The peak current reference signal for each module is the sum of the reference components from the OVR and IVS loops. The performance of the IVSPC control scheme is verified using an ISOP-connected prototype consisting of two flyback converters.