The problem of determination of the settings of HIF relays, substantially, depends on the conditions of distribution feeders such as their loads and configurations. In addition, for determining these settings, the balance between dependability and security of the
relay must be provided.
In this paper, operational procedures in companion with a set of algorithms are proposed, through which the computation of the HIF relay settings is performed in a systematically tunable
approach with the feeder conditions including topology and loadamounts. In this relay, the amount of energy, its steadiness and randomness for a certain order of harmonics in current waveform are used for HIF detection. These algorithms with exception to STCA, which is applied as off-line, are implemented on a DSP board that by installing the relay on any distribution feeder and setting it on appropriate modes, the thresholds can be determined.