Automatic locking method for flexible direct-current transmission system

Abstract

The invention discloses an automatic locking method for a flexible direct-current transmission system. The automatic locking method includes the following steps of firstly, judging the control mode of a station; secondly, judging the current running state when the flexible direct-current system runs if the station is judged to have the active power control mode; thirdly, starting the locking process of the station according to a received system locking control instruction if all the conditions are met, and conducting power reduction control; fourthly, sending a locking window signal to complete the locking process if both the active power and the reactive power of the current converter station are zero. By means of the automatic locking method for the flexible direct-current transmission system, a control and protection system in a flexible direct-current transmission project is automatically locked, the locking process of the flexible direct-current transmission system is shortened, impact which is caused by control and protection system incorrect operation generated due to man-made incorrect operation and the like to an alternating-current system is effectively avoided, time consumption of the whole locking process of the flexible direct-current system is lowered, the complexity in the locking process is lowered, and running reliability of a direct-current power grid is improved.

Description

Technical field [0001] The invention belongs to the field of flexible direct current transmission, and specifically relates to an automatic locking method of a flexible direct current transmission system. Background technique [0002] In the existing flexible DC transmission projects, no matter whether the double-terminal flexible DC project or the multi-terminal flexible DC transmission project, the entire flexible DC transmission system cannot be automatically locked. Each converter station is responsible for the blocking process of the local converter station. Under the unified deployment of dispatching, each converter station is locked in turn, which inevitably prolongs the entire system lock-up process, and increases the system lock-up process due to individual converter station tripping causing the entire system Risk of tripping. At the same time, in the entire blocking process, human factors dominate, which may cause the constant voltage control converter station in the f...

AI Technical Summary

Problems solved by technology

[0002] In the existing flexible DC transmission projects, regardless of the double-terminal flexible DC transmission project or the multi-terminal flexible DC transmission project, it is impossible to automatically realize the blocking of the entire flexible DC transmission system

Each converter station is responsible for the lockout process of the converter station at its own end. Under the unified deployment of dispatching, each converter station is locked in turn, which inevitably prolongs the lockout process of the entire system, and increases the tripping of individual converter stations during the system lockout process. trip risk

At the same time, in the whole blocking process, human factors play a dominant role, which may cause the fixed voltage control converter station to be blocked before the constant active power control converter station in the flexible DC system, resulting in malfunction of the control and protection system and affecting the stable operation of the AC and DC system.

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