Speed loss and variable pitch mixed control method for permanent magnetic direct drive wind generating set

Abstract

The invention provides a speed loss and variable pitch mixed control method for a permanent magnetic direct drive wind generating set and belongs to the technical field of generator control. The speedloss and variable pitch mixed control method for the permanent magnetic direct drive wind generating set comprises the steps that the value of the current wind speed and the values of the real-time power, the rotating speed and the pitch angle of the permanent magnetic direct drive wind generating set are detected; according to the values of the current wind speed, the real-time power, the rotating speed and the pitch angle, an equivalent wind speed method is used for carrying out calculation to obtain the wind speed, namely the equivalent average wind speed received by the front face of thecenter of a hub; and according to the relation between the equivalent average wind speed and the rated wind speed of the permanent magnetic direct drive wind generating set, the power output of the permanent magnetic direct drive wind generating set is controlled. The specific control method comprises three situations that 1, when the current wind speed is smaller than the rated wind speed, maximum power tracing control is adopted; 2, when the current wind speed exceeds the rated wind speed, constant-rotating speed control is adopted; and 3, when the current wind speed exceeds the rated wind speed, constant-power control is adopted. By means of the method, the problem that according to a permanent magnetic direct drive wind generating set variable pitch system, pitch angles are frequentlychanged, and consequently the failure rate is high is solved, and power output is more stable.

Description

technical field [0001] The invention belongs to the technical field of generator control, and in particular relates to a stall and pitch hybrid control method for a permanent magnet direct drive wind power generator set. Background technique [0002] Pitch control is the most common method to control the absorption of wind energy by permanent magnet direct drive wind turbines. By adjusting the pitch angle, constant power operation above the rated wind speed can be achieved. However, pitch adjustment makes the pitch angle move frequently, resulting in a relatively high failure rate of wind turbines. Fixed-pitch stall adjustment mainly depends on the unique airfoil structure of the blade. Since stall is a very complicated aerodynamic process, it is difficult to accurately calculate the stall effect for unstable wind conditions, so it is rarely used in large-scale wind turbines above the MW level. Control of wind turbines. [0003] In order to solve the above problems, a hybr...

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Problems solved by technology

However, the pitch adjustment makes the pitch angle move frequently, resulting in a relatively high failure rate of wind turbines

Fixed-pitch stall adjustment mainly depends on the unique airfoil structure of the blade. Since stall is a very complicated aerodynamic process, it is difficult to accurately calculate the stall effect for unstable wind conditions, so it is rarely used in large-scale wind turbines above the MW level. wind turbine control

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