100kW Inverter with 800V Power Bus and GaN Power Switches – Reference Design

March 17, 2020 by Paul Shepard

VisIC Technologies Ltd. today claimed a breakthrough using GaN for 800V power-bus motor inverter that can be used for a cost-effective EV motor drive. The University of Texas at Austin and VisIC Technologies cooperated on the 100kW inverter reference design that can be used as a base for inverter designs for EV, Industrial, PV, and other applications.

WBG power technology is fast becoming the technology of choice to replace Silicon power technology in EV Motor Drive to achieve better efficiency. It is commonly viewed that GaN technology will be used primarily in the 400V power-bus due to its lower cost compared to other WBG technologies, and SiC is commonly used in the high voltage 800V power-bus for higher power applications.

The new 100kW inverter reference design from VisIC proves that GaN technology can also be used in the 800V power-bus applications, producing the most cost-effective solution for both 400V and 800V EV power-bus.

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Based on VisIC's unique D3GaN technology, this 100kW inverter reference design can be adapted to work both under 800V and 900V power-bus. The VisIC GaN devices have highly thermal efficient SMD packaging, high threshold voltage, fast switching and easy paralleling for most cost-effective, highly efficient, and reliable inverter solution for EV.

The estimated peak efficiency can reach 99.3% with 40kHz switching frequency, due to the low switching losses of D3GaN devices. The total dimension is 26.9 × 21.4 × 3.5cm with the liquid cooling heatsink. The power density is 50kW/Liter including the liquid cooling. The total weight is about 2.5kg.

"Previously GaN has demonstrated its superior performance in achieving high power density for chargers. Thanks to VisIC GaN's superior packaging concept and low losses, we believe high power density can also be achieved in a very high-power application such as traction inverters", said Dr. Alex Huang, director of The Semiconductor Power Electronics Center at the University of Texas at Austin.

"We are very happy with the cooperation with the University of Texas as they've shown professional power design and innovative system solution," said Gregory Bunin, VisIC CTO  "this breakthrough will also enable the 800V EV power-bus to benefit from the GaN low cost and high-efficiency technology and provide cost-effective EV cars, for greener and cleaner planet".

As APEC 2020 was canceled the inverter reference design will be on display at PCIM, booth 9-137 in Nuremberg, Germany on July 28-30, 2020.