Current source type offshore wind power grid-connected system based on IGCT device

Abstract

The invention discloses a current source type offshore wind power grid-connected system based on an IGCT device. The current source type offshore wind power grid-connected system comprises an offshore wind power plant, a boosting transformer, an offshore sending end converter station, an onshore receiving end converter station and an onshore alternating current power grid. The offshore sending end converter station and the onshore receiving end converter station both adopt three-level current source type inverters; and the offshore wind plant is connected with the low-voltage side of the boosting transformer, and the alternating-current side of the offshore sending-end converter station is connected with the high-voltage side of the boosting transformer and used for converting alternating current into direct current to be conveyed. The direct current side of the onshore receiving end converter station is connected with the direct current side of the offshore sending end converter station, and the alternating current side is connected with the onshore alternating current power grid and used for converting direct current transmitted by the offshore sending end converter station into alternating current and transmitting the alternating current to the onshore alternating current power grid. According to the offshore wind power grid-connected system structure, an IGCT structure is adopted, the space requirement of an offshore sending end converter station is greatly reduced, and the light design target of offshore wind power is achieved.

Description

technical field [0001] The invention belongs to the technical field of offshore wind power grid connection, and in particular relates to a current source type offshore wind power grid connection system based on an IGCT device. Background technique [0002] The grid-connected transmission of offshore wind power usually adopts high-voltage alternating current transmission (HVAC) or high-voltage direct current transmission (HVDC). The HVAC technology is mature and the structure is simple, but limited by the capacitive effect of submarine cables, it is generally only suitable for the connection of offshore wind farms. With the large-scale development and layout of offshore wind farms gradually shifting from near sea to far sea, the application of traditional HVAC technology has gradually encountered bottlenecks. [0003] At present, the high-voltage direct current transmission technology used for long-distance large-capacity transmission is mainly LCC-HVDC based on thyristor li...

AI Technical Summary

Problems solved by technology

LCC-HVDC has low loss, high reliability, and mature technology. However, since the thyristor cannot be turned off by itself, it needs to be turned off by means of an external circuit, and cannot transmit power to passive and island networks, which also limits the application flexibility of this technology. ; At the same time, there is a risk of commutation failure on the LCC inverter side, which seriously threatens the safety of the system

VSC-HVDC control is flexible, there is no commutation failure problem, it can transmit power to the passive system, and the voltage polarity does not need to follow the change when the power is reversed, but the cost of IGBT, the core component of VSC, is high, and the capacity of the converter is relatively large. Small, the disadvantage is more obvious when used for large-capacity power transmission

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