A new approach of fast fault detection in HV-B transmission lines based on Detail Spectrum Energy analysis using oscillographic data

• This research work deals with a fast method for fault detection of High Voltage transmission lines.
• The DWT decomposes the current signals into Detail coefficients at level-1 for each phase current.
• Calculate the Detail Spectrum Energy (DSE) at level-1 of the Detail coefficients of the currents in each phase.
• A fault is detected when the sharp variation of the DSE in any phase must exceed the detection threshold.
• The fault type is identified, when the number of DSE sharp variation exceed two in each phase.

The main focus of this research is to develop an accurate real-time method for fault detection and analysis of HVB (High Voltage Class-B) transmission lines. The current and voltage signals of oscillographic records are acquired by the distance protections relays with minimum impedance GE D60-1 installed in the electrical network of SONELGAZ (Algerian Company of Electricity and GAS). This method deals on the evaluation of the Detail Spectrum Energy (DSE) calculated from the Discrete Wavelet Transform (DWT) applied on the current phases by moving data windows with length equivalent to one cycle of the fundamental power frequency. The fault detection algorithm is processed at first scale superimposed in the fault current signals (phases and ground) by the sharp variation of (DSE). Most of the existing methods treat the disturbances and faults simultaneously exist in transmission line as a single type. The proposed method has the ability to discriminate between the disturbances and the faults. This study is compared with the “Powerful Analysis of all Protection Fault Records” SIGRA software for determining the start fault inception and it’s clearing time. The performance of this method was tested and evaluated on a real data records and can accurately detect the fault within only half a cycle from the instant of fault occurrence.