METHODS AND APPARATUS TO FACILITATE GROUND FAULT DETECTION WITH A SINGLE COIL

摘要

Methods and apparatus to facilitate ground fault detection with a single coil are disclosed. An example ground fault detection device (200) includes a sense coil (204) to detect current in a line conductor (206) and a neutral conductor (208), the sense coil including a primary winding and a secondary winding L,. The example ground fault detector also includes a capacitor C, in parallel with the secondary winding L, and an inductor (214) to form a resonance circuit having a resonance frequency and having a signal proportional to the current, the signal indicative of a ground fault condition. An example method of detecting a ground fault includes driving a first capacitor C, with an inductor to generate a resonance signal component and monitoring an inductor signal to determine at least one of a neutral-to-ground fault, a line-to-ground fault, or a non-fault condition. The example method also includes generating a fault signal when at least one of the line-to-ground fault or the neutral-to-ground fault is detected.