30kW Three-Phase Vienna PFC Reference Design Leverages SiC Diodes and MOSFETs

July 31, 2019 by Paul Shepard

Microsemi Corporation offers the MSCSICPFC/REF5, a scalable 30kW, three-phase Vienna power factor correction (PFC) topology reference design featuring its silicon carbide (SiC) diodes and MOSFETS. Developed in collaboration with North Carolina State University (NCSU), the scalable, user-friendly solution is suited for fast EV charging and other high power automotive and industrial applications, providing customers with more efficient switching as well as high avalanche/repetitive unclamped inductive switching (UIS) and high short-circuit withstand ratings when utilizing the company's robust SiC MOSFETs and diodes.

This user-friendly 30kW three-phase PFC reference design includes design files for use with the company's next-generation SiC diodes and MOSFETS, open source digital control software and a user guide.

The topology offers advantages over single-phase PFC and two-level, six-switch boost pwm rectifier designs, which include operation in continuous conduction mode with extremely low distortion, reduced switching losses on power devices of approximately 98 percent for high efficiency and a compact form factor compared to Si/IGBT solutions.

The reference design also offers a detailed 3-D mechanical and thermal design with an integrated fan and cooling channel to reduce thermal resistance and total system size. Its printed circuit board layout was developed with considerations for safety, current stress, mechanical stress and noise immunity, and the reference design package features ready-to-use hardware and verified open source software to reduce the technical risk of high power switching designs while accelerating product time to market.

Key features of this three-phase Vienna rectifier reference design:

  • Initial operation at 20kW and designed for 30kW applications
  • Microsemi's next generation SiC diodes and SiC MOSFETs with high avalanche/repetitive unclamped inductive switching (UIS)
  • Three-phase, 380/400 V RMS, 50Hz or 60Hz input voltage
  • 140kHz switching frequency
  • 780Vdc output voltage
  • PCB layout with consideration for safety, current stress, mechanical stress, and noise immunity
  • Open source software for digital control
  • Maximum ambient temperature at 60°C

"As the automotive market transitions toward more HEV and battery-electric cars, SiC allows for better efficiency, resulting in better mileage. This continues to drive high demand for these SiC devices in our portfolio, as well as our other high-reliability product offerings," said Leon Gross, vice president and business unit manager for Microsemi's Discrete and Power Management group.

"After successfully releasing our SiC MOSFET and diode product portfolio over the past few years, our new three-phase three-switch three-level PFC reference design is a concrete example of how to leverage these parts in demanding applications that showcase its ruggedness, high performance and overall value," Gross added.

In addition to its suitability for fast EV/HEV chargers and high power three-phase power supplies in the automotive and industrial markets, Microsemi's new active three-phase PFC reference design can also be used in medical, aerospace, defense and data center markets. This reference design adds to the company's overall SiC solutions portfolio, which can also be used for HEV/EV charging, conductive/inductive onboard charging, dc-dc converters, EV powertrain/traction controls, photovoltaic inverters and actuation applications.