System and method for controlling low voltage ride through of high-power direct-driven permanent magnet wind power generation system

Abstract

The invention belongs to a wind power generation technology, and relates to a system and a method for controlling low voltage ride through of a high-power direct-driven permanent magnet wind power generation system. The system comprises a full power converter which is positioned between a wind power generator and a power grid and consists of a machine side converter and a grid side converter, and a Crowbar circuit is connected onto a direct current bus of the full power converter. According to the system and the method, protection for the converter can be realized well when the voltage of the direct-driven permanent magnet wind power generation system drops in the power grid, and the low voltage ride through can be realized well through the cooperation with a converter system.

Description

technical field [0001] The invention belongs to wind power generation technology, and relates to a low-voltage ride-through control system and a control method of a high-power direct-drive permanent magnet wind power generation system. Background technique [0002] As a new energy industry, wind power has developed rapidly in recent years, and its installed capacity has continued to increase. With the continuous increase of installed capacity of wind power, it has become a mandatory requirement for wind power generators to have "low voltage ride through function". As the core component of wind power generators, converters must have this function. According to the basic principle of the wind power generation system, during the voltage drop, the system will generate large current and high voltage, so a protection device must be designed in the converter system to prevent damage to the converter. [0003] Compared with doubly-fed motors, permanent magnet direct-drive fans are ...

AI Technical Summary

Problems solved by technology

When the grid voltage drops, the output voltage of the direct-drive permanent magnet wind power generation system drops. At this time, the output current must be increased to maintain the balance between the power absorbed by the converter from the wind turbine and the output power to the grid. When the drop is large, the input and output power are unbalanced, causing the DC side voltage to rise, which poses a threat to the insulated gate transistor (IGBT) and capacitor of the main circuit of the converter.

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