Ground Fault Detection and Location Method for AC/DC/DC Converters with Supercapacitor Systems

The integration of power electronic converters has become essential for the proper operation of electrical systems. However, the use of such devices, including inverters and rectifiers, complicates ground fault detection, particularly in back-to-back converter systems. This paper introduces a method for detecting and locating ground faults in DC systems that incorporate $\text{AC} / \text{DC} / \text{DC}$ converters and a supercapacitor system. The proposed approach analyses the voltage signal across a grounding resistor, which connects the system's neutral point-either the AC neutral point of the main power transformer's star configuration or an artificial DC midpointto the ground. By analyzing the voltage waveform, it is possible to identify ground faults and determine whether the fault is associated with the positive or negative pole, or the AC side. The proposed method has been validated through multiple simulations, achieving accurate results across different fault scenarios.