Method for monitoring unbalanced current at stator side after inter-turn short circuit in hydro-generator rotor

A method for monitoring an unbalanced current at a stator side after inter-turn short circuit in a hydro-generator rotor. The method adopts a super-long data window technology, and automatically adjusts the length of a data window according to the number of pole-pairs of a generator, thereby achieving an accurate calculation of fractional harmonic of different units. In this method, an effective value of a fault circulating current is calculated accurately, and fundamental waves, third harmonic waves, and fifth harmonic waves in the unbalanced current during normal operation are filtered out effectively, thereby improving the sensitivity of monitoring the inter-turn short circuit fault in generator rotor windings.