Vienna Rectifier-Based, Three-Phase PFC Reference Design

October 04, 2018 by Paul Shepard

Vienna rectifier power topology is used in high-power three-phase power factor correction (PFC) applications such as off-board EV chargers and telecom rectifiers. Control design of the rectifier can be complex. The TIEVM-VIENNARECT reference design from Texas Instruments illustrates a method to control the power stage using C2000™ microcontrollers.

The hardware and software available with this design can help accelerate time to market. This design illustrates how to control a Vienna rectifier using a C200-MCU.

Three-phase power is used by equipment operating at high power in industrial applications. To improve grid power quality and reduce the harmonic currents drawn, power factor correction is needed as many of the forward loads are dc. For example, in an offboard, fast EV charger, operating at 20kW, the input is a three-phase ac connection from the grid and the output is dc to the battery.

Though many topologies exist for active three-phase power factor conversion, a Vienna rectifier is popular due to its operation in continuous conduction mode (CCM), inherent multilevel switching (three level), and reduced voltage stress on the power devices.

Traditionally, hysteresis-based controllers have been used for Vienna rectifiers. Only recently have sine triangle-based PWM been shown to work for Vienna Rectifier control. This control can be quite challenging to design. Several variants of Vienna rectifiers exist, the figure below shows the variant of the Vienna rectifier chosen in this design along with the key voltages and currents being sensed.

Vienna Rectifier Variant Implemented (click on diagram to enlarge)

A Y-connection Vienna rectifier is implemented in this TI Design. With this design the aim is to provide an example of how to control a Vienna rectifier and how to tune the different loops using the C2000 MCU.

TIEVM-VIENNARECT Vienna Rectifier-Based Three-Phase Power Factor Correction Reference Design Using C2000™ MCUs

Features of this reference design:

  • Hardware Features
    • EVM with interface to accept HSEC180 controlCARDs
    • Greater than 98% peak efficiency
    • Less than 2% THD at full load and low line
    • Up to 2.4kW design with three phase 400Vac VL-L Input
    • Hardware Files are in DigitalPower SDK at solutions\tidm_1000
  • Software Features
    • Free download of Code Composer Studio IDE
      • Free download of C2000WARE-DIGITALPOWER-SDK which includes application libraries, firmware for this EVM and device drivers and example projects for C2000 MCUs
      • Firmware of this EVM supporting F28004x and F2837x MCU
      • Control operation can be run on either the main C28x CPU or CLA
    • Free download of controlSUITE for device drivers and example projects
    • Easy adaptation of software and tuning of custom power stage using powerSUITE tools: Solution Adapter, SFRA and Compensation Designer
      • SFRA enables in circuit verification of control loop design