Flexible direct current power distribution network high-impedance grounding fault detection method based on color relationship classifier

Abstract

The invention discloses a flexible direct current power distribution network high-impedance grounding fault detection method based on a color relationship classifier, which comprises the steps of: firstly, carrying out extraction of characteristic mode components on a transient state zero mode current by adopting a variational mode decomposition algorithm, and carrying out comparison and distinguishing on a fault state and a normal state by adopting the characteristic mode components; then, calculating Euclidean distances of the characteristic mode components, converting the Euclidean distances into gray scales, and calculating a mean value of the gray scales; and finally, converting the mean value of the gray scales into a hexagonal cone spatial model by adopting the color relationship classifier, and according to hue, saturation and brightness values, further determining an operation state. Compared to an existing high-impedance fault diagnosis method, the fault detection method disclosed by the invention has a flexible inference model, and is high in fault detection reliability; the color relationship classifier model is convenient to embed into equipment; real-time monitoring is implemented; complexity in the fault detecting process is overcome; and meanwhile, the calculation speed is improved.

Description

technical field [0001] The invention belongs to the technical field of power grid fault detection, and in particular relates to a method for detecting a high-resistance grounding fault in a flexible DC distribution network based on a color relationship classifier. Background technique [0002] At present, the DC distribution network has developed rapidly with the diversity of energy sources used at the user end and the increase in load energy. The investment of resources by many scholars and researchers has also promoted the maturity of the DC distribution network technology. In order to solve the problem of high investment cost of the traditional AC distribution network due to the demand for a large number of power electronic converter equipment, the mature DC distribution network technology has become the first choice for people to choose power distribution methods, and with the development of power electronic technology Rapid development, progress in converter technology,...

AI Technical Summary

Problems solved by technology

When there are intermittent faults in the distribution network, due to the small damping value of the DC line, the DC does not have a zero-crossing point, resulting in re-ignition after the fault arc is extinguished, and the high self-healing ability of the fault makes it difficult to remove the fault

On the other hand, there are many high-resistance faults in the distribution network, and 2-5% of the fault resistance is a high-resistance fault, but the DC discharge time is short, and the discharge is almost completed within a few microseconds. It is difficult to obtain fault data, and the fault data window is short. Existing fault protection measures cannot obtain effective fault information synchronously, resulting in failure of line protection

In addition, there are many high-resistance faults and it is difficult to distinguish high-resistance faults from signals during normal operation, which increases the difficulty of fault identification. At the same time, high-resistance faults are very harmful, and the distribution network is located in an area with frequent human activities, which will easily cause huge personal injuries. Security and Grid Stability Issues

However, the current research on flexible DC high-resistance grounding faults is very little, and these are worthy of in-depth study by scholars.

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