What accuracy can we expect from the single-ended fault locator?

In spite of the existence of more accurate fault location methods, such as multi-ended and travelling wave fault locators, the majority of digital relays in the field still use single-ended fault locator method. User expectations for the fault locator accuracy are very high, as it affects how fast faulted line component can be identified and repaired. This paper explains major selected methods used for the single-ended fault locators in digital relays. Principles of each method are described and then the accuracy of each fault locator method is demonstrated for different fault types and power system conditions under influencing factors. Results and conclusions have been supported and illustrated by simulations, and explained to readers. Commonality among the selected location methods is examined. The suggestions are presented for readers to better understand, analyze and validate fault locator results.