Variable speed-variable pitch combined control method of variable speed constant-frequency wind turbine generator

Abstract

The invention discloses a variable speed-variable pitch combined control method of a variable speed constant-frequency wind turbine generator. According to the control method, an optimal rotating speed estimated value and a rotating speed reference value are introduced to respectively serve as reference quantities of rotating speed control and variable pitch control. A rotating speed PID controller performs torque command regulation according to the deviation of the optimal rotating speed estimated value and the rated rotating speed of the wind turbine generator, a variable pitch PID controller performs pitch angle command regulation according to the deviation of the rotating speed reference value and the rated rotating speed of the wind turbine generator, decoupling control between rotating speed control and variable pitch control is achieved, and interference between rotating speed control and variable pitch control is avoided. When wind speed fluctuates nearby the rated value and pneumatic power captured by the wind turbine generator is larger than rated power, the rotating speed reference value corresponding to a pneumatic power estimated value is larger than the rated rotating speed of the wind turbine generator, the variable pitch PID controller regulates a pitch angle command before a torque command output by the rotating speed PID controller reaches the rated value, and variable speed-variable pitch combined control is achieved in advance to control rotating speed of the wind turbine generator and overshooting of output power.

Description

technical field [0001] The invention relates to a control method of a variable-speed constant-frequency wind turbine, in particular to a variable-speed and variable-pitch joint control method of a variable-speed constant-frequency wind turbine. Background technique [0002] Most of the existing large-scale variable-speed constant-frequency wind turbines use variable-speed and variable-pitch operation. When the wind speed is lower than the rated wind speed, the power of the unit is usually adjusted according to the output of the speed controller to achieve the maximum wind energy capture control of the unit. When the wind speed is higher than the rated wind speed , the pitch controller begins to control the action of the pitch actuator to reduce the aerodynamic power absorbed by the unit and maintain the normal operation of the unit. When a large-scale variable-speed constant-frequency wind turbine operates near the rated wind speed, how to effectively control the unit will d...

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Problems solved by technology

[0006] Although the above-mentioned patents have realized the smooth switching and control of variable speed and variable pitch, when the wind speed fluctuates near the rated value, they have not fully utilized the joint control advantages of variable speed and variable pitch control, and cannot effectively control the sudden increase of aerodynamic power. Control, fan speed and power are prone to overshoot

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