16 November 2011

SemiSouth’s SiC JFETs used by Japan’s FUPET in record output power density, small-volume inverter

SemiSouth Laboratories Inc of Starkville, MS, USA, which designs and manufactures silicon carbide (SiC) transistor technology for high-power, high-efficiency, harsh-environment power management and conversion applications, says that its SiC junction field-effect transistor (JFET) are being used in small inverters (measuring 0.5 litres in volume) to achieve an output power density of 30kWh/l. If inverters of this size and capacity are used with photovoltaic (PV) panels, then one inverter could supply enough electricity for up to five households, it is claimed.

A team at the Japanese academia and industry R&D Partnership for Future Power Electronics Technology (FUPET), involving Fuji Electric, Nissan Motor, Sanken Electric and Toshiba, aims to deliver power converters that operate at high temperature with high output power density. Using SiC JFETs from SemiSouth, the team developed a three-phase 500cc inverter that delivers 15kW output power when connected to a three-phase motor with a conversion efficiency of 99%. Featuring a compact, optimized cooling system, the power modules can operate at up to 2000C (Shinji Sato et al, Yusuke Zushi, Kohei Matsui, Yoshinori Murakami and Satoshi Tanimoto: International Conference on Silicon Carbide and Related Materials (ICSCRM 2011), paper Tu-P-23).

“This is the world’s highest output power density for a small-volume inverter,” believe Satoshi Tanimoto, chief researcher at FUPET’s R&DCenter. “SemiSouth’s JFETs have been instrumental in helping us maximize efficiency and power density,” he adds.

SemiSouth’s JFETs are compatible with standard gate driver ICs, and feature a positive temperature coefficient for ease of paralleling; extremely fast switching with no ‘tail’ current at up to a maximum operating temperature of 1500C and a low RDS(on)max. Devices are available in TO-247 packaging and in some cases they are also available in die form for integration into modules.

“The FUPET team achieved these results at 50kHz, which is their minimum frequency target, and the module also has a very low inductance module with only 5nH,” comments president & chief technology officer Jeff Casady. The FUPET team aims to achieve an inverter with 40kW/l output power density next year.

Tags: SemiSouth SiC JFETs

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