Project brief
A 22kW DC fast charging station for electric vehicles, supporting CCS Combo 2, CHAdeMO, and GB/T 20234.3 charge protocols. The power electronics stage uses SiC MOSFETs in an interleaved two-phase boost PFC followed by a phase-shifted full bridge DC-DC converter with synchronous rectification, achieving 96.2% peak efficiency. OCPP 1.6 JSON protocol enables cloud-based energy management.
The project describes a charger integrating power electronics and communications. The explanatory workflow adds no interoperability or compliance certification evidence.
The engineering challenge
Coordinate power conversion, vehicle negotiation, session control, and supervisory connectivity.
Engineering approach
- Separate the power stage from protocol and session-management functions.
- Use negotiated voltage and current targets within converter control.
- Integrate protection inputs, user authentication, and remote status reporting.
Features & capabilities
- 22kW DC output: 50–500V / 0–50A programmable (per protocol negotiation)
- CCS Combo 2 (IEC 62196-3), CHAdeMO 2.0, GB/T 20234.3 multi-standard
- SiC MOSFET PFC + PSFB topology, 96.2% peak efficiency at full load
- Power Factor: >0.99 across 10%–100% load range
- OCPP 1.6 JSON over WebSocket: remote start, stop, status, billing
- RFID card authentication (ISO 14443A) + mobile QR code payment
- Ground fault detection, arc fault detection, emergency stop circuit
- IEC 62133, IEC 61851-1, IEC 61851-23 compliance framework
Software & engineering tools
SiC MOSFETs (Wolfspeed C3M), STM32G4, Ethernet (W5500), custom 8-layer PCB, OCPP 1.6 implementation