Method and system for controlling pitch angle of wind turbine generator under power failure condition of power grid and device

Abstract

The invention discloses a method and system for controlling the pitch angle of a wind turbine generator under the condition of power failure of a power grid and a device, and belongs to the field of wind power generation. By detecting a power failure signal of the power grid, front and back acceleration signals of a cabin are introduced to participate in variable pitch control logic at the moment of executing a pitch stop shutdown operation, and the generator is prevented from experiencing the limit load to the greatest extent. The operation safety of the generator under the extreme wind condition is improved, real-time variable-rate pitch stop shutdown is adopted, the dynamic response characteristics of the whole machine are fully considered, and a corresponding variable-rate pitch stop instruction is calculated in real time. Under the power failure condition of the power grid, the front and back accelerations of the cabin are adopted as control input to participate in variable pitch control, the defect that the vibration condition of a tower and the whole machine is not considered in a traditional mode is overcome, and a cabin front and back acceleration-variable pitch rate control ring is introduced innovatively on the basis of the constant pitch stop rate. The dynamic response information of the whole machine in the detected front and back acceleration signals of the cabin is fully utilized, and the limit load of the tower is reduced in the variable-pitch action changing in real time.

Description

technical field [0001] The invention belongs to the field of wind power generation, and relates to a method, system and equipment for controlling the pitch angle of a wind turbine under the condition of a power grid failure. Background technique [0002] The tower is an important supporting part of the wind turbine, and its stress under different operating conditions affects the reliability and life of the tower. When encountering extreme wind conditions while the wind turbine is in a special situation, the superimposed extreme load tests the bearing capacity of the tower, which further seriously affects the normal and stable operation of the wind turbine. When the wind turbine generator encounters a power failure of the grid, the converter will be disconnected from the grid instantaneously, and the torque of the generator will suddenly drop to zero. Experiencing the ultimate bending moment is not conducive to the long-term stable operation of the wind turbine. Therefore, ...

AI Technical Summary

Problems solved by technology

When encountering extreme wind conditions while the wind turbine is in a special situation, the superimposed ultimate load tests the bearing capacity of the tower, which further seriously affects the normal and stable operation of the wind turbine.

When the wind turbine generator encounters a power failure of the grid, the converter will be disconnected from the grid instantaneously, and the torque of the generator will suddenly drop to zero. Experience the ultimate bending moment, which is not conducive to the long-term stable operation of the wind turbine

Images