Study on the Stabilization of Operating Performance of DC Earth Leakage Breaker Using Fluxgate DC Sensor

In recent years, the need to use DC power distribution systems has increased and there has been a growing public interest in ensuring their safety. In particular, residual current devices (RCDs) are recognised as an important piece of protective equipment for users, preventing not only equipment accidents but also personal accidents. Therefore, it is necessary to verify the operation of DC RCDs in advance. Therefore, this paper investigates a stable sensor data processing method and algorithm of DC RCDs to ensure the safety of DC electrical equipment and protect people from electric shock. DC RCDs use a fluxgate current sensor as the DC ZCT, but as the fault current increases, the pulse generation frequency increases and distortion occurs. In addition, when the fault current is such that the core is saturated, the pulse generation is interrupted and the fault current is not detected and the breaker does not operate. To solve these problems, a data processing technique has been used which applies compensation by frequency analysis of the magnetic excitation circuit of the sensor to stabilize the operating performance of the protection device. The DC RCD developed in this paper can be used as a protective device to ensure the safety of DC equipment and to protect people from electric shock, and it is judged that it will contribute to ensuring electrical safety by ensuring safety in the event of a fault and taking appropriate preventive measures by confirming the exact cause of the operation of the protective device.