Design of Variable Inductor for Powertrain DC-DC Converter

摘要

Variable Inductor (VI) uses a small control current to modulate the permeability of a magnetic core and regulate its characteristics. This makes it suitable for applications with a stringent space limitation and a wide range of load variations. Nonetheless, this device is composed of multiple windings and several quantities can be used. Hence, its design is a demanding task and it is even much more complex in case of electric vehicles (EV) converters. This paper provides a systematic design procedure of VI taking into consideration of the nature and requirements of a three-wheel recreational electric vehicle. A VI is designed for a 33 kW nominal and 82 kW peak bidirectional DC-DC converter. Unlike the classical methods, the design procedure is based on the RMS current rather than the peak current. The designed VI is evaluated with FEM simulations. In comparison to the peak current design, the RMS based design and the use of VI resulted in 46% volume reduction.