Bidirectional Battery Charger Uses Three-Phase Two-Level PFC
What you'll learn:
- What are the two power stages in STMicro's bidirectional battery charger?
- Key differentiating features of the charger.
Offering a complete solution for high-voltage charging for both industrial and automotive applications, the STEVAL-11BID1KCB 11-kW bidirectional battery charger developed by STMicroelectronics consists of two power stages: a power-factor-correction (PFC) and an isolated DC-DC stage.
The PFC stage leverages a three-phase full-bridge topology, and the DC-DC section features a dual-active-bridge (DAB) topology. Both stages are based on the ACEPACK DMT-32 silicon-carbide (SiC) power module.
The board uses two control boards for the PFC and DC-DC stages; the control boards are based on the STM32G474RE microcontroller. The PFC stage has a 70-kHz operating frequency, while the DC-DC stage operates at a fixed switching frequency of 100 kHz.
Maintaining a peak system efficiency of 96%, other features of the charger include a PFC stage 3-phase, 2-level bidirectional AC-DC power converter with a rated nominal AC voltage of 400 V AC at 50 Hz, and a rated nominal DC voltage of 800 V DC.
Nominal power is 11 kW, and in rectifier mode, the power factor is greater than 0.99. Coupled with inrush current control, soft startup, and active and reactive power control, the charger presents an integrated grid-connection solution. The DAB switching frequency of 100 kHz and soft-switching behavior are enabled by enhanced modulation management.
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About the Author
Alix Paultre
Editor-at-Large, Electronic Design
An Army veteran, Alix Paultre was a signals intelligence soldier on the East/West German border in the early ‘80s, and eventually wound up helping launch and run a publication on consumer electronics for the US military stationed in Europe. Alix first began in this industry in 1998 at Electronic Products magazine, and since then has worked for a variety of publications in the embedded electronic engineering space. Alix currently lives in Wiesbaden, Germany.
Also check out his YouTube watch-collecting channel, Talking Timepieces.