Direct-current arc fault detection and positioning method based on pulse polarity characteristic distribution spectrogram

Abstract

The invention discloses a DC arc fault detection and positioning method based on a pulse polarity characteristic distribution spectrogram. The DC arc fault detection and positioning method comprises the following steps: step one, connecting coupling capacitors in parallel to all branches in a DC power distribution network system; step two, generating series or parallel arc faults at different positions in the DC power distribution network system, detecting the current of each branch capacitor, and then performing discrete wavelet transform on the current of each branch capacitor to obtain capacitive current spectrum ranges at different positions and of different fault types; step three, drawing a characteristic distribution spectrogram according to the capacitive current spectrum ranges and the capacitive current pulse polarities of different positions and fault types; and step four, under the condition that a to-be-processed system generates an arc fault, acquiring the capacitive current spectrum distribution range and the current pulse polarity information of each branch in the to-be-processed system, and determining the type and the position of the arc fault of the to-be-processed system by utilizing the characteristic distribution spectrogram. Therefore, the direct current arc fault of the power system can be detected and located.

Description

technical field [0001] The invention belongs to the field of fault diagnosis and relates to a DC arc fault detection and positioning method based on a pulse polarity characteristic distribution spectrum. Background technique [0002] In the DC distribution network system, affected by the environment and operating conditions, the metal joints of the contact elements are loosened under mechanical vibration, and the insulation aging of the DC power supply line under long-term operation may cause DC discharge. DC is different from AC discharge. Once DC discharge develops into an arc, it is difficult to extinguish because its current does not cross zero. The methods used for AC arc fault detection and control cannot be directly applied to DC arc faults. DC arc ablation of contact elements will eventually lead to connection failure. The high temperature generated by the combustion will ignite the surrounding non-flame retardant materials at the same time, and a chain reaction will...

AI Technical Summary

Problems solved by technology

DC is different from AC discharge. Once DC discharge develops into an arc, it is difficult to extinguish because its current does not cross zero. The methods used for AC arc fault detection and control cannot be directly applied to DC arc faults.

DC arc ablation of contact elements will eventually lead to connection failure. The high temperature generated by the combustion will ignite the surrounding non-flame retardant materials at the same time, and a chain reaction will occur, resulting in large-scale fire or even explosion, which poses a serious threat to the safe operation of the equipment. Therefore, it is necessary to develop a Detection and location method of DC arc fault

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