30 kW Interleaved LLC

The 30 kW 3 phase interleaved LLC DCDC converter (CRD-30DD12N-K) targets high-power-density, high-efficiency fast charger applications and features Wolfspeed’s discrete 1200V C3M Silicon Carbide MOSFETs (C3M0040120K) and 650V C6D Silicon Carbide Schottky Diodes (C6D20065D and C6D10065A). A 3-phase interleaved LLC topology is implemented to provide low input current ripple and high efficiency for EV high power fast charger. Discrete power devices offer cost effective and common package solutions. The reference design accommodates all different levels of EV charging with a wide output voltage range of 200V-1000V while maintaining a high power density of 6.5kW/L and higher than 98% peak efficiency. The adaptive control operates over a 130kHz-250kHz switching frequency range to maintain optimal control over all operating conditions. To achieve the listed output voltage range, input voltage must be actively adjusted between 650V and 900V. In the end application, this can be achieved using an active-front-end AC-DC converter. The secondary side of the converter is manually configurable for series or parallel operation depending on the output voltage range required. The design accomplishes:

• Peak efficiencies over 98.3%
• Power density of 6.5kW/L

This reference design is offered as a comprehensive design package which can be used as a starting point for new SiC designs.

Parallel Output Configuration

• Output Voltage:
  • 200V-250V DC, 66A max
  • 250V-500V DC, 100A max, 30kW max

Series Output Configuration

• Output Voltage:
  • 500V-1000V DC, 50A max, 30kW max

• Switching Frequency: 130-250kHz
• Extruded heatsink with forced air cooling
• CAN interface with PC based graphical user interface