60 kW Dual Active Bridge Isolated DC/DC Converter

The 60 kW Dual Active Bridge (DAB) isolated DC/DC converter reference design demonstrates how Wolfspeed’s innovative Gen 4 baseplate-less SiC power modules are tailormade for renewable energy, energy storage, and high-capacity fast-charging applications. The 60 kW DAB topology is implemented with only two full-bridge GM4 power modules attached to a single coldplate – taking advantage of the isolated substrate of the baseplate-less power modules to further improve the realized power density. The high switching frequency of 100 kHz enabled by SiC reduces the size of the isolation transformer and widens the output voltage/power range while still achieving ZVS operation of both primary and secondary bridges. Moreover, with proper design consideration, only the leakage inductance of the high-frequency transformer is needed for adequate power transfer, eliminating the need for an extra bulky magnetic component. Overall, the inherent bi-directional capability and ease of paralleling make the DAB topology well suited as a modular building block to scale to higher power. The use of Wolfspeed Gen 4 baseplate-less SiC power modules simplify the system design while improving system efficiency, durability, reliability, and scalability.

Design Advantages:

• Peak efficiency of 99.2%
• >98.8% efficiency across operating range above 20 kW
• Power density of 10.5 kW/L including transformer
• Isolated topology for safety
• Zero-voltage turn-on switching with wide output voltage range
• Utilizes isolation transformer leakage inductance (no large standalone inductor required)
• Modular building block that can be paralleled to achieve higher power levels
• Inherent bi-directional capability