Control protection processing method of grounding-pole-free mode operating of direct-current engineering

Abstract

Disclosed is a control protection processing method of a grounding-pole-free mode operating of direct-current engineering. A direct-current station control system, a direct-current pole control system and a direct-current protection system are matched to realize control protection, an instation grounding switch interlocking condition is set as forced satisfaction by the direct-current station control system, and by the direct-current station control system, a judgment condition of the grounding pole connecting states is set as cancelling relevancy to the instation grounding switch sub-states in a rectifier station, and in an inverter, a judgment condition for instation grounding switch sub-states in the rectifier station is set as forced satisfaction. The direct-current pole control system is provided with a bipolar synchronous locking / unlocking unit, a bipolar current follow unit and a bipolar intertrip unit. The control protection processing method solves the problem of keeping bipolar balance operating when the direct-current engineering uses an instation grounding grid as a grounding pole, and is scientific, effective and capable of meeting demands of engineering application.

Description

technical field [0001] The invention relates to the technical field of electric power systems, in particular to a control and protection processing method for direct current projects operating in a non-grounded electrode mode. Background technique [0002] The grounding electrode is an important part of the conventional DC engineering. It not only plays the role of clamping the DC neutral point potential, but also provides the ground as the current return path for the DC single-pole ground return method and the double-pole grounding method. Therefore, if There is no grounding pole, although the DC neutral point potential can be clamped by the grounding network in the station, the earth cannot be used as the current return path. Therefore, if a unipolar block occurs during DC bipolar operation, the DC current will not have a transfer circuit and cause bipolar atresia. DC will usually not be able to run bipolar, but can only run in the form of unipolar metal loops, which will...

AI Technical Summary

Problems solved by technology

However, under the existing technical conditions, when the grounding grid is used as the grounding point on the rectifier side, it cannot be used in the single-pole operation mode because the design principle of the grounding grid is different from that of the grounding electrode.

In addition, in order to reduce the grounding current and its duration as much as possible, the unlocking of the two poles and emergency shutdown must be completed in the shortest possible time; at the same time, considering the electrical corrosion of the grounding current to the grounding grid, a cathode must be used The protection law protects the grounding grid, and the existing technologies are currently unable to meet the above requirements

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