High impedance fault detection in distribution networks integrated with distributed generation using fast discrete orthonormal Stockwell transform

•A new method based on FDOST presents to detect HIF from other disturbances.•The presented method is simple to implement and has a low computational burden.•The proposed method to detect HIF is accurate, fast and robust against noise.•The presented method has proper detection time and accuracy in presence of DGs.•The proposed method is used to detect HIFs for recorded HIFs in a real feeder. Detection of high impedance fault (HIF) from other disturbances such as switching on/off the capacitor bank, linear and nonlinear loads, distributed generation (DG), induction motor, and inrush current is very important. To improve the detection time and accuracy of all disturbance types with and without DGS, a new method is proposed based on the fast discrete orthonormal Stockwell transform (FDOST). The proposed detection index is defined as the ratio of Shannon entropy of the real part of the FDOST coefficients of the current signal energy to its Kurtosis. The method only requires half a cycle of post-disturbance current. The method is tested on the IEEE 13-node and IEEE 34-node test feeders, as well as the real HIFs on a feeder in Iran. The results show the efficient performance of the method with and without DGs under normal and noisy conditions with an average detection time of about 3.5 ms.