Next generation 4.5 kV IGBT StakPak module and FRD for 8GW HVDC application

Abstract:
This paper discusses Hitachi Energy’s recent achievements related to next generation semiconductor devices for operation within 8 GW VSC-HVDC systems with MMC topology. For this purpose Hitachi Energy’s most recent additions to its StakPak’s insulated gate bipolar transistor (IGBT) press-pack platform, the 4.5 kV / 2.5 kA and 4.5 kV / 5 kA Gen-1 IGBT-only StakPak modules are presented. Furthermore, a brief description of the company’s newly developed 4.5 kV fast recovery diode (FRD) platform will also be given. Finally, simulation results of the combined operation of the Gen-1 IGBT and a selected FRD will be showcased. The IGBT modules are based on Hitachi Energy’s SPT++ planar IGBT technology. An improved variation of this technology (Gen-1) features 600 mV reduced VCEsat compared to the reference (Gen-0) IGBT technology, boosting current capability while keeping turn-off losses unaffected. Additionally, an advanced backside technology design used in the Gen-1 IGBT reduces collector-emitter leakage current by more than 50%, enabling high temperature operation at Tvj(op)= 150 °C. The technology possesses best in class reverse bias safe operating area switching capability with tests performed at Tvj=150 °C, IC > 2x Inom (VCC = 3.6 kV) on module level and excellent short circuit pulse withstand time tp well above 10 mus (VCC = 3.6 kV) as measured on submodule level. Hitachi Energy’s Gen-1 IGBT combined with its FRD, which features a wide SOA and high surge current capability offers major potential for 8 GW VSC-HVDC systems, thus accelerating the transition to a green energy future.