Design of 1200-V RC-IGBT for TOYOTA's 5th generation HEV/PHEV systems

We developed a new 1200-V reverse conducting insulated gate bipolar transistor with a structure called Schottky and multi-layered anode (a unique carrier injection control approach without lifetime-control) for TOYOTA's 5th generation hybrid electric vehicle and plug-in hybrid electric vehicle systems. The developed devices reduced total losses (conduction and switching losses) by 10% compared to the conventional product. It also reduced the number of parts for the power module and contributed to its 25% size reduction, ultimately contributing to the downsizing of 13% of the power control unit.

I. Introduction

Recently, there has been a major wave of technological innovation in the automotive industry toward realizing a sustainable future mobility society. One of these is the electrification of the powertrain. Therefore, auto manufacturers are developing various types of electrification vehicles (xEVs), such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs) and battery electric vehicles (BEVs). All these vehicles are powered by motors controlled by a power control unit (PCU). The PCU contains an inverter that converts the DC power supply to AC. The core component of the inverter is the power module. A power module has multiple power semiconductor devices (insulated-gate bipolar transistors (IGBTs) and diodes). Fig. 1 shows that power semiconductor devices account for approximately 20% of the electrical power losses in an xEV. Hence, higher PCU efficiency can be achieved by reducing power semiconductor device losses. In addition, more compact power modules are required to reduce the cost, size, and weight of PCUs.