Detection method of series direct-current arc in direct-current brush motor electrical circuit

Abstract

The invention discloses a detection method of a series direct-current arc in a direct-current brush motor electrical circuit. According to the method, one capacitor is connected in parallel to the twoends of a direct-current brush motor which generates interference high-frequency components, and a part of the interference high-frequency components are filtered out; and an inductor is connected inseries to a circuit between the direct-current brush motor which generates the interference high-frequency components and a current probe for series direct-current arc fault detection, so that high-frequency components generated by electrical equipment are prevented from flowing through the current probe for series direct-current arc fault detection. The current probe is used for measuring the capacitance and current in a detection circuit at a direct-current output side. By detecting the current measured on the current probe and performing time-frequency domain analysis on the current, generation of a series direct-current arc fault in the direct-current circuit can be judged according to increase of the amplitude of the current in a frequency domain. Through the method, an interferencehigh-frequency signal brought by the direct-current brush motor in the arc fault detection circuit can be filtered out, and the influence of the interference high-frequency signal on series direct-current arc detection is prevented.

Description

technical field [0001] The invention belongs to the field of electrical engineering, and relates to a method for detecting a series DC arc fault in an electrical system of a DC brushed motor. Background technique [0002] With the further development of modern industry, DC systems are widely used in fields such as aerospace and electric vehicles. In a DC system, series DC arc faults will occur due to loose connectors and aging cables. Since the DC current has no zero-crossing point, after the series DC arc fault occurs, the arc will not be extinguished naturally, which is more likely to cause fire and other dangers. [0003] When a series DC arc fault occurs in a DC system, it is equivalent to connecting a non-linear resistor in series in the system, which will reduce the DC current amplitude in the system, and high frequency components will be generated with the series DC arc fault. The main detection method of series DC arc fault is the indirect detection method by detec...

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Problems solved by technology

Y.S.Oh et al. performed wavelet eigenvalue decomposition on the simulated series DC arc current, and used the obtained wavelet detail coefficient and wavelet approximation coefficient as characteristic parameters to detect the generated series DC arc, but this method lacks actual experimental verification , the accuracy needs further study

[0004] However, since the DC brushed motor will generate high-frequency current in the electrical circuit during normal operation, the normal high-frequency current will interfere with the detection of series DC arc faults based on time-frequency domain characteristics, and the existing technology cannot be directly applied to DC brushed motors. In the DC system of the motor

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