Full-current composite high-voltage direct current transmission system

Abstract

The invention relates to a full-current composite high-voltage direct current transmission system. The full-current composite high-voltage direct current transmission system includes a rectification station, an inversion station and an overhead power transmission line; the rectification station adopts thyristor converters; the positive pole and negative pole of the rectification station both comprise a twelve-pulse thyristor converter; the inversion station adopts fully-controlled power electronic device-based current source-type converters; the positive pole and negative pole of the inversion station both include two series-connection current source-type converters; positive and negative pole connection points of the rectification station and the inversion station are connected with a grounding pole or an intra-station grounding grid according to situations in which the direct current transmission system is in bipolar, mono-polar ground return or mono-polar metal return operation modes; and the rectification station is connected with the inversion station through the overhead power transmission line. The full-current composite high-voltage direct current transmission system of the invention is advantageous in flexible operation mode and high reliability. The full-current composite high-voltage direct current transmission system of the invention is especially suitable for long-distance high-voltage direct current overhead transmission, and is also particularly applicable to the upgrading and reconstruction of the existing full-thyristor type high-voltage direct current transmission. The full-current composite high-voltage direct current transmission system is further advantageous in convenience and practicability.

Description

technical field [0001] The invention is a full-current compound high-voltage direct current power transmission system capable of solving the problem of phase commutation failure on the inverter side, and belongs to the innovative technology of the compound high-voltage direct current power transmission system. Background technique [0002] The HVDC power transmission system using thyristor converters in both the rectifier station and the inverter station has the advantages of less damage, relatively low cost, and high reliability. However, commutation failures are prone to occur during the inverter operation of thyristor converters. For multiple DC centralized feed-in grids, AC system failures may cause multiple converter stations to fail commutation at the same time, causing a huge impact on the grid and seriously affecting the safety of the system. Stablize. [0003] The use of voltage source converters based on fully-controlled power electronic devices in the inverter st...

AI Technical Summary

Problems solved by technology

However, commutation failures are prone to occur during the inverter operation of thyristor converters. For multi-circuit DC centralized feeding into the grid, AC system failures may cause multiple converter stations to fail commutation at the same time, causing a huge impact on the grid and seriously affecting the safety of the system. Stablize

[0003] The use of voltage source converters based on fully-controlled power electronic devices in the inverter station can solve the problem of commutation failure, but it also brings new problems. The inverter station uses the DC side as a voltage source, and the thyristor The rectifier station of the converter regards the DC side as a current source, and the two stations operate in different modes, which makes it difficult to coordinate and control

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