Double-fed fan local damping control system for suppressing low-frequency oscillation of system

Abstract

The invention provides a doubly-fed fan local damping control system for suppressing low-frequency oscillation of a system. The doubly-fed fan local damping control system comprises a doubly-fed fan, a rotor-side PWM converter, a grid-side PWM converter, a rotor-side controller, a grid-side controller, a damping controller, a pitch angle controller and a wind turbine controller, the damping controller forms a pitch angle compensation signal according to the power grid frequency and transmits the pitch angle compensation signal to the wind turbine controller; the pitch angle controller calculates a pitch angle instruction value according to the wind speed and transmits the pitch angle instruction value to the wind turbine controller; the wind turbine controller calculates a mechanical power reference signal according to the pitch angle compensation signal and the pitch angle instruction value, and outputs the mechanical power reference signal to a rotor side controller; and the rotor side converter generates a driving signal according to the mechanical power reference signal in combination with the collected active power, reactive power and grid-connected point three-phase voltage emitted by the fan, and outputs the driving signal to the rotor side PWM converter. The low-frequency oscillation generated when the fan is connected to the power grid is effectively suppressed, and the grid connection stability of the fan is improved.

Description

technical field [0001] The invention belongs to the technical field of wind power generation, and in particular relates to a local damping control system of a double-fed fan for suppressing low-frequency oscillation of the system. Background technique [0002] In the prior art, there is a technical solution of applying a damping controller to a feedback fan. In the patent 201110175859.2, a method of using the additional damping controller of the wind turbine to improve the system damping is disclosed. Based on the basic principle of the optimal speed control of the doubly-fed wind turbine, the additional damping controller is designed by introducing the low-frequency oscillation characteristic signal after the AC grid is disturbed. The output of the damping controller is the modulation component of the control speed of the fan, and the adjustment of the active output is realized by controlling the speed of the fan, so as to achieve the effect of suppressing the oscillation o...

AI Technical Summary

Problems solved by technology

However, for complex systems, the design process is too complicated, and the calculation of related parameters is large

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