STEVAL-7BIDIRCB [STMicroelectronics]

The STEVAL-7BIDIRCB is a solution for a 7 kW bidirectional charger, consisting of two stages:

1) bidirectional three-channel interleaved totem pole PFC working at fixed frequency in continuous conduction mode (CCM). The three-channel interleaved PFC architecture guarantees the highest efficiency in a wide load range.

2) bidirectional resonant full bridge CLLC with synchronous rectification. The CLLC uses frequency modulation to regulate the output.

The two stages are digitally controlled by two STM32G474RET6 microcontrollers that are mounted in a single control card.

The power stage is fully composed by ST's SiC power MOSFETs, driven by STGAP SiC dedicated gate drivers with galvanic isolation. Thanks to a modular system architecture in combination with the HU3PAK package, a power density of 4 kW/l is achieved.

The PFC operates at a switching frequency of 65 kHz and the CLLC operates at variable frequency from 130 kHz to 350 kHz.

Thanks to the excellent switching performance of the SiC GEN3 and its Rds(on) temperature stability, a peak efficiency of 97.1 % is achieved in charger mode.

The solution is also suitable to implement a solar integrated ESS, thanks to provision for MPPT stage connection.

• Open-frame power density: 4 kW/l (66 W/inch³)
• Cooling: natural air convection