Third Generation BM3 Silicon Carbide Power Modules Boost Railcar Power System Designs

Smaller in size, lighter in weight, and more efficient in operation, Wolfspeed Silicon Carbide (SiC) requires fewer components than conventional silicon (Si) for auxiliary power in train and traction and offers higher performance due to the unique characteristics of the wide bandgap material.

The newly released Wolfspeed 1200 V third generation BM3 SiC power modules offer the most diverse product range in an industry standard 62 mm package. The BM3 module is designed to meet the requirements of applications with superior system power and efficiency. Developed by Wolfspeed, it redefines the possibilities for energy-efficient design in railways and various industrial applications. The forthcoming 1700 V and higher specification BM3 SiC modules, designed for harsh environments, will further take the BM3 portfolio to a new level.

Wolfspeed is a preferred, vertically integrated Silicon Carbide provider due to its unmatched, 35+ year history and expertise working with SiC power devices. Wolfspeed’s third generation SiC MOSFETs and sixth generation SiC Schottky diodes in the BM3 module product line represent this rich history, culminating in the performance and reliability required to meet a wide variety of industrial and energy management applications. These latest generation SiC devices enable critical applications to obtain higher switching frequencies, higher operating temperatures, higher breakdown voltages, and lower power losses.

In the recently launched 1200 V BM3 product family, Wolfspeed released six half-bridge module variants. The various configurations cover industrial and THB-80 (HV-H3TRB rated) specifications with current ratings from 175 A to 530 A. Wolfspeed’s third generation SiC MOSFETs feature lower on-state resistance than its predecessors, allowing applications to process more power, to run at lower temperatures increasing reliability, and to decrease the size of the required cooling system. Wolfspeed’s latest sixth generation SiC Schottky diode technology has zero reverse recovery loss and offers lower conduction and switching losses than the body diodes typically used by other suppliers.

The new Wolfspeed 1200 V BM3 portfolio offers excellent amperage capability up to 530 A in a standard 62 mm footprint, including solutions with anti-parallel Schottky diodes for applications with high switching frequencies. The THB-80 qualified modules and the forthcoming designs for harsh environments keep the modules robust in extreme temperature and humidity environments. The Wolfspeed BM3 modules have an optimized internal layout achieving the industry’s lowest stray inductance in a 62 mm package, which facilitates practically negligible switching losses and minimizes overshoot for maximum voltage utilization. The only requirements to make the upgrade from the 62mm IGBT package are a short transition time and low development costs. The new 1200 V Wolfspeed BM3 portfolio is suitable for designs in railway and traction, industrial power supplies and test equipment, medical power supplies, and off board fast charging for EVs.

Wolfspeed also offers a series of evaluation kits to quickly and easily examine the performance of BM3 modules. Dynamic performance and system level prototyping can be done by combining Wolfspeed’s evaluation kits with their reference design gate drivers. The evaluation kit features a low power loop inductance of 6 nH for 1200 V (8 nH for the forthcoming 1700 V evaluation board). The gate driver boards allow for switching frequencies up to 70 kHz and feature high-speed overcurrent protection circuitry. The higher switching speeds enabled by SiC components give designers the tools to create railcar power systems which are smaller and lighter than existing systems.

Railcar power systems are demanding. Wolfspeed is up to the challenge. Explore our products to learn more about how Wolfspeed Silicon Carbide can bring higher performance and reliability in train and traction power system designs.