| 摘要 |
<p>Apparatus for detecting the direction of a fault in relation to a switch (14) connected between a source (10) and a load (16) includes a voltage sampler and a current sampler for generating voltage and current samples during first and second power cycles. A first comparator (66, 68, 70) compares the current samples from the first and second cycles and determines the sign of the difference between the samples. A second comparator (72) compares the sign of the voltage from the first cycle to the sign of the current difference determined by the first comparator and provides an indication of fault direction. The apparatus also includes a fault inception determiner (46, 50) for providing a fault inception indication determined by comparing the voltage samples from the first and second cycles and detecting the sign of the difference between the samples.</p> |
