Design of a Wide-Input Isolated Fast Solid-State Circuit Breaker with Programmable Trip Current Function

This study presents a design for a protective circuit featuring fast tripping functionality. The main power switch employs a normally-on Silicon Carbide Junction Field Effect Transistor (SiC JFET) and a fast-start isolated converter as the gate driver. The self-biased solid-state circuit breaker detects short circuit faults by monitoring current surges in the main loop. The isolated converter rapidly establishes the triggering voltage to deactivate the SiC JFET, ensuring swift interruption of short circuit currents. A programmable approach utilizing PWM signals enables adjustment for varying fault conditions and tripping current thresholds. The circuit breaker can be integrated directly into the circuit loop without external power or additional wiring. Control is managed by the MCU-ATMEGA328P microcontroller, supporting a DC grid voltage of 100 V to 400 V and a maximum load of 6 kW. The reset mechanism incorporates Modbus wired communication and Bluetooth wireless functionality. Experimental results indicate a minimum detection tripping time of 50.49 μS for short circuit currents..