Phase II year
2014
(last award dollars: 2016)
Phase II Amount
$1,999,223
For the batteries, PM motor and electric drive train while simultaneously reducing weight. Increasing the drive train conversion efficiency has a significant impact as it extends battery life, vehicle range and allows for a reduction of heavy cooling components through the reduction of heat generating losses. Therefore much attention is placed on increasing the efficiency of the traction power inverter that drives the electric motor. It is well documented that inverter efficiency and power density can be increased while simultaneously reducing weight through the use of Silicon Carbide (SiC) wide bandgap semiconductors. For example, demonstrations of inverters utilizing SiCJFETs and SiCMOSFETs are emerging, where the efficiencies are reaching >99% with 10X increased power densities. However, todays electric vehicle motor drive applications require high current (200400A) power modules. SiC devices have been limited to lower current (<50A) due to the material defects, lower yields and higher costs associated with large area devices. For the electric vehicle traction inverters, it is of great interest to push up the SiC device current to 100200A per device to make full use of the SiC system. Material defect densities have dropped dramatically in recent years as the commercial acceptance of the SiC Schottky diode have driven higher volume and more state of the art semiconductor fabrication. To address topic 17b, USCi proposes in Phase II to fabricate 200A 650V and 1200V 100A SiC Schottky Diodes on 6 diameter wafers. The high current diodes will complete reliability automotive qualifications in Phase II. The diodes will be copackaged with Si switches to form hybrid modules and benefits estimated. When integrated, the SiC diodes will increase the efficiency of electric motor power conversion from the battery to the drive train.
Keywords: Silicon Carbide, Diodes, Electric Vehicle, Inverters, High Current