Shutdown control method and shutdown control device of wind turbine generator set

Abstract

The invention discloses a shutdown control method and a shutdown control device of a wind turbine generator set. The control method comprises the steps that signals of power network voltage are detected; when the power network voltage is changed to zero, a loop is switched from a power network to an energy dissipation device, a standby power source simultaneously begins to supply power to the set, so that a normal shutdown flow is started; and after the upper limit of the capacity of the energy dissipation device is reached, the connection between the set and the energy dissipation device is cut off, and an emergent shutdown flow is started till the set reaches a shutdown state. The shutdown control device has the advantages that when a network disconnection fault occurs and the set shuts down, rotating kinetic energy of an impeller is absorbed by the energy dissipation device, and blades are enabled to feather at a relatively low variable-pitch rate to maintain the aerodynamic damping, thereby reducing the load of the set and preventing the occurrence of impeller overspeeding.

Description

technical field [0001] The invention relates to a shutdown control method of a wind power generator set, in particular to a shutdown control method and device of a wind power generator set. technical background [0002] The tower of the wind turbine is a flexible structure, which has the characteristics of low natural frequency and small damping. This feature causes greater vibration and load during the shutdown of the unit when an off-grid fault occurs. It is common practice to reduce vibration and reduce loads simply by reducing the pitch rate during shutdown. [0003] The main goal of existing methods is to make the aerodynamic damping produced by the rotation of the impeller disappear more slowly, thereby slowing down the vibration of the tower. However, at the same time, the blades are still at an optimal angle of attack, and the rotational torque of the impeller is still relatively large, which is very likely to cause overspeeding of the impeller, that is, the rotati...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the technical problem that the existing wind power generating set has a large load in the shutdown process when an off-grid fault occurs, the present invention provides a wind power generating set shutdown control method and device that is simple in principle and easy to implement

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