Grounding device for offshore wind power flexible direct current delivery system and control method thereof

Abstract

The invention discloses a grounding device for an offshore wind power flexible direct current delivery system and a control method thereof. The grounding device comprises a reactance group, an isolation switch group and a grounding resistor. The reactance group is formed by star connection of three-phase iron core large reactance and forms an artificial neutral point. The isolation switch group isformed by three-phase rapid BPS star connection and forms a manual grounding point. The reactor group and the isolation switch group form double-star connection, and the two artificial neutral pointsare connected through the isolation on-off SN. The grounding resistor is composed of two groups of resistors. The resistor R1 and the resistor R2 are respectively connected with the neutral points ofthe reactor and the isolating switch, and the lightning arrester is connected in parallel with the grounding resistor R2. The device freely switches the grounding resistance value according to the requirements of steady-state operation, modulation mode, starting process, transient process, fault state and the like of the system so as to meet different operation conditions and modulation modes. And the adopted star-shaped isolating switch device is used for protecting the reactor group in a transient severe fault, so that the safety of the device is ensured.

Description

technical field [0001] The invention belongs to the technical field of new energy and electric power engineering, and in particular relates to a grounding device and a control method for an offshore wind power direct transmission system. Background technique [0002] With the continuous development of electric power technology, the capacity of offshore wind power generation is constantly expanding, especially the effective development and utilization of wind resources in remote sea areas. The development of offshore wind farms in remote sea areas is of great significance to solving the energy crisis. With the increasing energy problems, and with the continuous operation of onshore flexible direct current transmission and new energy grid-connected projects. Offshore wind power technology is about to usher in a full-scale explosion, and a large number of offshore wind power projects will enter the construction stage in the next few years. Grid-connected operation has become t...

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Problems solved by technology

[0004] In some soft straight projects, there have been problems such as grounding device failures or grounding methods that do not match the temporary and steady-state processes of the system.

However, there are very few studies on the grounding method of offshore wind power, and the grounding method adopted is still based on the grounding of the soft direct system on land, and cannot simultaneously satisfy steady-state operation, transient process, start-up and fault conditions during the design process. Require

In addition, the industry has not carried out research on the safety of the grounding device of the offshore wind power direct transmission system itself.

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