Device and method for giving early warning about main transformer DC magnetic bias event

Abstract

The invention discloses a device and method for giving an early warning about a main transformer DC magnetic bias event. The device comprises a plurality of GPS clock modules, a plurality of shunts, aplurality of AC / DC synchronous acquisition modules, a data monitoring module, a big data analysis module and an early warning module; a main transformer neutral point ground loop in each monitoring point is connected in series with a shunt; each shunt is provided with a wiring terminal for sampling an AC / DC signal flowing through the main transformer neutral point; each shunt and the GPS clock module corresponding thereto are electrically connected to an AC / DC synchronous acquisition module; each AC / DC synchronous acquisition module communicates with the data monitoring module through a communication module; the data monitoring module is connected with the big data analysis module; and the big data analysis module is connected with the early warning module. The device can analyze the synchronism of DC fluctuations at multiple monitoring points, identifies a DC magnetic bias event, quickly identifies the type and hazard level of the DC magnetic bias event, locates a harmonic source, and provides a decision basis for grid operators and maintainers.

Description

technical field [0001] The invention relates to the technical field of transformer DC bias, in particular to a device and method for early warning of transformer DC bias events. Background technique [0002] When a DC current flows through the neutral point of the transformer, it will cause abnormal phenomena such as increased transformer noise, increased vibration, voltage waveform distortion, and local overheating of the transformer. Monitoring the DC current and harmonic current at the neutral point of the transformer can accurately reflect the operating status of the transformer. . Identifying whether there is a DC bias phenomenon in the AC grid is of great significance to prevent the risk of DC bias of the main transformer and ensure the safe operation of the AC grid. [0003] In the field application, the DC bias magnetic monitoring device is affected by the performance of the sensor and the environment, and there are still many limitations, which seriously affect the...

AI Technical Summary

Problems solved by technology

[0003] In the field application, the DC bias magnetic monitoring device is affected by the performance of the sensor and the environment, and there are still many limitations, which seriously affect the DC bias magnetic monitoring effect of the main transformer.

For example, the zero point drift of the Hall core sensor is large, and it is easy to be damaged under the fault current, which cannot meet the long-term use requirements; the flat steel clamp is used to sample from the flat steel at the neutral point of the main transformer, which is affected by the material and length of a section of flat steel to be sampled. The consistency and measurement accuracy of the sensor cannot be guaranteed

At present, there is no relevant application for monitoring the mixed current at the neutral point of the main transformer to analyze and warn of DC bias events.

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