CISSOID collaborates on High Power Density SiC Inverters
3-Phase SiC Power Stack combines 1200V SiC Intelligent Power Module and a 6-pack low-ESR/ESL DC-Link capacitor from Advanced Conversion
CISSOID, a maker of high temperature semiconductors and power modules, has collaborated with the NAC Group and Advanced Conversion to offer a compact and optimally integrated 3-Phase SiC Power Stack combining a 1200V SiC Intelligent Power Module from CISSOID and a 6-pack low-ESR/ESL DC-Link capacitor from Advanced Conversion.
This Power Stack can be further integrated with a controller board and a liquid cooler offering a complete hardware and software platform for the design of high power density and high efficiency SiC Inverters (see picture) for e-motor drives.
“The DC link is a critical component for high-power inverters using fast switching that is often overlooked during the initial stages of design. However, efficient fast switching wide bandgap devices requires a carefully designed DC link bus topology with tightly integrated capacitors, ” says James Charlton , director of product marketing at NAC Group, who have collaborated with Advanced Conversion to develop a range of kits for use with the CISSOID module”.
“Thanks to the capacitor kit customers can find immediately a high-performance capacitor perfectly suited with our fast-switching 3-Phase SiC IPM’s, accelerating their inverter design for compact and efficient e-motor drives” says Pierre Delatte, CTO of CISSOID.
CISSOID’s Intelligent Power Module (IPMs) platform integrates a 3-Phase 1200V/340A-550A SiC MOSFET Power Module with a temperature-robust gate driver enabling low switching losses and high power density. This platform can be further enhanced with a control board and algorithms providing real-time processing, control and functional safety for SiC inverters in e-motor drives. The power module On Resistance ranges from 2.53mOhms to 4.19mOhms depending on current rating. The total switching energies are as low as 7.48mJ (Eon) and 7.39mJ (Eoff) at 600V/300A.
The co-design of the power module and the gate driver enables optimising the IPMs for lowest switching energies by carefully tuning dV/dt and controlling voltage overshoots inherent to fast switching. The embedded gate driver solves multiple challenges related to fast-switching SiC transistors: negative drive and Active Miller Clamping (AMC) prevent parasitic turn-on; Desaturation detection and Soft-Shut-Down (SSD) react rapidly but safely to short-circuit events; Undervoltage Lockout (UVLO) functions on gate driver and DC bus voltages monitor the proper operation of the system.
The 6-pack DC-Link capacitor from Advanced Conversion mechanically fits to CISSOID IPMs through a low inductance busbar. A set of capacitor values, up to 500µF, and of voltage ratings, up to 900V, is available for rapid evaluation. Custom solutions are also available, based on advanced Conversion annular form factor film capacitor that is ideally suited for “surface mounting” to an optimised bus structure that interfaces with the switch modules.
This patented approach combined with bus cooling provides a very high Ampere per micro-Farad rating to allow the smallest possible capacitance while simultaneously minimising the commutation loop inductance. Equivalent series inductance values of less than 5nH are readily achieved using the right switch module with an appropriate connection design.