A microgrid fault detection method, device and storage medium

Abstract

The present invention relates to a microgrid fault detection method, device and storage medium. The method includes the following steps: obtaining an eigenvalue sequence corresponding to the eigenvalue of the DC side of the microgrid; processing the eigenvalue sequence to obtain the eigenvalue filter Sequence, the eigenvalue filtering sequence includes a plurality of filter values; respectively determine the difference between each of the filter values ​​and the predetermined value; determine the corresponding feedforward weighting factors of the filter values ​​according to each of the differences, And determine the weighted differential value of the feature quantity according to each of the feedforward weight factors; determine the fault information of the microgrid according to the weighted differential value. The technical scheme of the invention can effectively distinguish fault transient signals and noise signals, has strong anti-interference ability and high sensitivity.

Description

technical field [0001] The invention relates to the field of microgrid fault detection, in particular to a microgrid fault detection method, device and storage medium. Background technique [0002] Microgrid refers to a small power generation and distribution system composed of distributed power sources, energy storage devices, energy conversion devices, loads and protection devices. There are significant differences. Especially on the DC side of the microgrid, the low inertia DC power supply and load will cause the rapid development of fault characteristics when a fault occurs. In order to protect the microgrid, it is necessary to quickly remove and isolate the fault. At the same time, under the complex topology of AC-DC hybrid connection, it is also necessary to effectively identify the DC side disturbance caused by the AC side fault of the microgrid, and prevent the protection malfunction on the DC side. [0003] During the operation of the microgrid, the high-frequency...

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Problems solved by technology

[0003] During the operation of the microgrid, the high-frequency switching of the rectifier and inverter bidirectional power converters will cause ripples and interference from external noise on the DC side of the microgrid, which will easily cause the protection of the microgrid to malfunction or reduce the resistance to over-resistance. Among them, the fault transient signal is a wide-band continuous signal, which overlaps with the frequency band of the noise signal. Only the introduction of filtering means cannot effectively filter out the noise. At the same time, it will cause signal delay and increase the detection time, which is not conducive to the safety of the microgrid.

[0004] At present, the common DC microgrid fault detection method is the differential component protection method, which reflects the occurrence of the fault through the change of voltage and current during the fault transient period, and has high sensitivity and quickness, but it is not sensitive to external noise and interference very sensitive

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