Duty cycle charts and its application to multiport DC-DC converters in vehicular applications

Abstract

Multi-port dc-dc converters can be extensively used for power flow management within electric vehicle power distribution system. These converters are characterized by presence of multiple controllable switches which are used to realize different regulation objectives simultaneously. When the duty ratios corresponding to each control objective are shared within a switching interval, the resultant pulse-width-modulation (PWM) scheme consists of phase-shifted control signals with varying widths. This work considers duty-cycle charts to facilitate mapping of each of the control variables to each of the actual control switch operating duty ratios. The proposed concept has been evaluated using a non-isolated three-port dc-dc power electronic interface, known as integrated dual-output converter (IDOC), which can provide two dc-outputs: one step-up and the other step-down type. The duty cycle chart concept has been used to evaluate the operating modes of the converter topology, thereby identifying the limits of its operation. The proposed theory has been validated using simulated results. � 2024 selection and editorial matter, Kundan Kumar, Ambrish Devanshu and Sanjeet K. Dwivedi; individual chapters, the contributors.