High impedance fault detection based on Stockwell transform and third harmonic current phase angle

• Published in: Electric power systems research 2019-10, Vol.175, p.105931, Article 105931
• Main Authors: Lima, Érica Mangueira, Brito, Núbia Silva Dantas, Souza, Benemar Alencar de
• Format: Article
• Language: English
• Subjects: Activation; Capacitor banks; Distribution management; Fault detection; Fault diagnosis; Fault location; Harmonics; High impedance; High impedance faults; Multiresolution analysis; Networks; Parameter estimation; Phase shift; Power distribution protection; Signal processing; Standard deviation; Stockwell transform; Substations; Topology
• ISSN: 0378-7796; 1873-2046
• DOI: 10.1016/j.epsr.2019.105931

•A new high impedance fault detection method for distribution networks.•Using only the third harmonic phase angle estimated by the Stockwell transform.•Requires a single measurement point on the substation.•Distinguish high impedance faults from other distribution network disturbances.•Not affected by system characteristics, fault inception angle and fault location. A new method for high impedance fault detection is proposed in this paper. Stockwell transform is used to extract the third harmonic current phase angle, measured only at the substation, whereas the moving standard deviation continuously monitor this parameter. The fault is detected when the standard deviation is below a self-adaptive threshold for a predetermined period of time. To validate the method, a real distribution network is adopted, considering a modeled stochastic noise based on real current signals. Results show that the proposed method is able to quickly detect high impedance faults in different types of contact surface and fault locations, without causing false positives. It can also differentiate high impedance faults from other distribution network disturbances such as capacitor banks switching, feeder energizing and low-impedance faults. Moreover, results suggest that the proposed method is not affected by fault location or inception angle, system loading and topology changes in the distribution network.