Mission Profile-Oriented Active Thermal Control of a Bidirectional Three-Level Buck-Boost GaN-Based DC-DC Converter for Electric Vehicles Powertrains

One of current challenges in high-density electric vehicles (EVs) is the efficient thermal control of power converters and the reliable management of power flows in motoring/breaking mode for the battery bank. In this line, this paper presents an Active Thermal Control (ATC) scheme to regulate thermal stress in Gallium Nitride High Electron Mobility Transistors (GaN HEMTs) devices of a three-level bidirectional buck-boost DC-DC converter (TLBBC) as a power interface between battery and motor inverter. The TLBBC is designed to operate at a rated power of 20 kW as part of a modular system, by using parallel GaN devices. Proposed control schemes are implemented using systematic linear control design. Finally, the system is simulated and tested for a Mission Profile-Oriented (MPO) based on Highway Fuel Economy Test (HWFET) in order to validate the proposed control schemes.

I. Introduction

Today, the need to use sustainable and clean energy is imperative and utilization of electric transport is a clear example to achieve this fundamental objective. In fact, this is reflected by an increased number of electric vehicles (EVs) within the automotive fleet worldwide [1]. High-density power converters solve the new challenges given by these new technologies, such as power-building-block design of high-power chargers and efficient powertrains [2], [3].