Design of Current Reconstruction Devices for Low-Frequency and High-Frequency Components in Arc Faults

In order to provide a low-cost, portable test platform for Arc Fault Detection Devices (AFDD) and enhance product development efficiency, arc fault current reconstruction device is needed. Based on frequency domain analysis of the arc current signal, the signal is decomposed into high-frequency (HF) and low-frequency (LF) components for separate reconstruction. A LF current reconstruction device is designed. By regulating the gate-source voltage of the MOSFET based on the input voltage and feedback voltage, the MOSFET is mainly maintained in its linear region, forming a voltage-controlled resistor to reconstruct the target LF current signal. A HF sensor is employed to capture the time-frequency domain characteristics of the arc current’s HF component, which provides the target for signal modulation. The modulated HF signal is then coupled into the current generation circuit via a Class E power amplifier and an HF magnetic core. The same HF sensor is used to verify the reconstruction fidelity. Test results demonstrate that the devices are capable of reconstructing both LF signals and HF signals in specific bands.