Commutation failure prediction control method and device based on direct-current (DC) electric quantity

Abstract

The invention discloses a commutation failure prediction control method and device based on a direct-current (DC) electric quantity, which is used to prevent the phenomenon that in a high-voltage or ultrahigh-voltage DC system, failure of a DC side of some pole causes commutation failure of a healthy pole through mutual inductance between the two poles. The method is characterized in that a suddenincrement (or sudden increments) of an absolute value (or absolute values) of the DC voltage and/or the DC current of a current pole in some time window is/are detected in a real-time manner; and when the sudden increment(s) of the absolute value(s) of the DC voltage and/or the DC current exceeds/exceed a preset threshold (or preset thresholds), an extinction angle of an inversion side converterof the current pole is enlarged through a DC control system, so that the commutation failure of the current pole is prevented. The method provided by the invention is applicable for prediction and prevention of the commutation failure of the healthy pole caused by the failure of the DC side of the other pole, and has the advantages of high response speed and high action accuracy.

Description

technical field [0001] The invention belongs to the field of high-voltage and ultra-high-voltage direct current transmission, and in particular relates to a method for predicting and controlling a direct current commutation failure and a device thereof. Background technique [0002] In my country, high-voltage and ultra-high-voltage direct current play an important role in the realization of west-to-east power transmission, water and fire mutual aid, and large-scale optimal allocation of energy resources. At present, the newly-built UHV DC project presents the characteristics of high voltage, large capacity, and long distance, which leads to some new characteristics of the DC system under abnormal disturbances, and brings new challenges to the design of DC control and protection systems. [0003] For a DC transmission system with a long distance between the sending and receiving converter stations, the mutual inductance between the two poles of the DC system, that is, the el...

AI Technical Summary

Problems solved by technology

Although this method avoids the sampling and judgment of the AC electrical quantity, since the method is judged according to the size of the time interval, its response time is still relatively long. there are still some limitations

[0008] In summary, the traditional commutation failure prediction method and its improvement measures, as well as the control method based on inter-pole communication, all have the problem of long response time, and cannot effectively avoid the commutation failure of healthy poles caused by a DC side fault of one pole. , therefore, it is necessary to study a new commutation failure prediction control method according to the characteristics of the actual DC project, so as to provide guarantee for the normal operation of the actual DC project

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