Review of the Wide-Input-Wide-Output Bi-directional DC-DC Converter for Electric Vehicle Applications

Abstract

Electric vehicles (EVs) are becoming very popular nowadays to reduce the consumption of oil and environmental pollution. The use of battery and super-capacitor is increasing as the power-source of EVs. The bi-directional DC-DC converter is essential to integrate the battery and super-capacitor with the motor of the vehicle. However, a conventional second-order bi-directional DC-DC converter cannot give very high/low output voltage due to its efficiency reduction at extreme duty cycles, which is prerequisite for EVs. The problems of achieving high efficiency in wide-input-wide-output (WIWO) voltage range bidirectional operation using a conventional bidirectional converter are summarized in this paper. Additionally, the available converters from the literature for WIWO voltage range operation are discussed in detail. The various wide voltage range DC-DC converters are classified into different categories based on their operating principle. Additionally, the advantage and disadvantages of these various wide voltage range converter topologies are explained for the EV application. Finally, a general conceptual solution to achieve a WIWO converter with high efficiency is proposed. It is essential to change the voltage level of the motor input as per the speed requirement. Hence, this paper presents a clear idea for the WIWO bi-directional converters for EV application.