Prediction method of DC bias current affecting stations under different operation modes of multiple DC grounding poles

Abstract

The invention discloses a method for predicting the influence of DC bias current on a site under different operating modes of multiple DC ground electrodes. By installing a DC on-line monitoring device at the neutral point of a transformer near the DC ground electrodes, the actual measurement data of the distribution of the DC bias current can be grasped. , and then according to the measured data, adjust the soil resistivity and thickness of each layer to correct the simulation model, and then use the revised soil model to predict the influence of DC bias magnetism under different operating conditions of the power grid in multi-DC grounding pole areas. For DC For transformers whose current exceeds the set value, protective measures can be taken in advance, so as to achieve the purpose of targeted DC bias current protection. The invention has the beneficial effects of improving the early warning capability of the DC bias magnetic field of the power network transformer, and facilitating the timely adoption of effective protection measures for transformers with relatively high DC bias magnetic risk.

Description

technical field [0001] The invention relates to the technical field of substation operation management, in particular to a method for predicting the influence of DC bias current on a station under different operation modes of multiple DC grounding poles. Background technique [0002] In recent years, my country's direct current transmission has developed rapidly, and the problem of unbalanced distribution of energy and load centers has been effectively alleviated. However, the problem of direct current bias of transformers caused by direct current transmission has become more and more prominent. When transformers are biased by direct current, there will be aggravated vibration and noise. Phenomena such as increase and local overheating will cause problems such as loose tensioning parts inside the transformer, broken windings, damage to insulating materials, loose and bent iron sheets, etc. If the duration is too long, it will also cause damage to the transformer. The DC bias ...

AI Technical Summary

Problems solved by technology

Establish the target power grid model through simulation calculation, and calculate the influence of DC bias magnetic field under different operating conditions of the power grid in areas with multiple DC grounding poles according to the geographical location of each substation and DC grounding pole, as well as the DC resistance of the transmission line and the DC resistance of the transformer However, due to the complex geological conditions of the power grid, the ground modeling part in the simulation model cannot accurately simulate the real situation, which brings errors to the calculation, and cannot accurately calculate the DC current distribution in the power grid, let alone realize multi-DC grounding Prediction of the influence of DC bias magnetism under different operating conditions of power grids in polar regions

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