Doubly-fed fan subsynchronous oscillation suppression method based on stator reactive hierarchical control

Abstract

The invention discloses a doubly-fed fan synchronous oscillation suppression method based on stator reactive hierarchical control. The method includes the steps of: S1. adopting a TLS-ESPRIT algorithm to identify and detect system subsynchronous oscillation; S2. when occurrence of subsynchronous oscillation of the system is detected, whether the decrease degree of subsynchronous oscillation in the system reaches a preset value is judged at short intervals [delta]t; S3. after reactive power transmitted by a doubly-fed fan stator is increased by one grade, judging whether inductive reactive power transmitted by the stator exceeds a limit of a reactive power regulation capability under a current wind speed state; S4. performing stator reactive hierarchical control, enabling the stator to increase transmitted reactive power by one grade, and returning to the Step S2 to continue to judge; and S5. ending a reactive hierarchical control strategy, and giving an alarm. The doubly-fed fan subsynchronous oscillation suppression method adopts hierarchical control, and can reduce influence of increase of transmitted reactive power on an original system as much as possible; and the method only needs to control a reactive power reference value of the doubly-fed fan stator, the control method is simple, and does not need to change a controller structure and increase extra investment equipment, and the control cost is low.

Description

technical field [0001] The invention relates to the field of power system control, in particular to a subsynchronous oscillation suppression method of a doubly-fed fan based on stator reactive power classification control. Background technique [0002] With the continuous increase of wind power installed capacity and the application of series compensation technology in large-scale wind power transmission, subsynchronous oscillation accidents caused by series capacitor compensation have occurred in many double-fed wind farms at home and abroad, which have caused serious damage to the safe and stable operation of the power system. Serious harm. [0003] In the existing research, the subsynchronous oscillation suppression methods of the wind power external transmission system are mostly based on the classical phase compensation control theory, and the additional damping controller installed in the controller of the doubly-fed wind turbine is designed and installed. Although th...

AI Technical Summary

Problems solved by technology

Although the additional damping controller belongs to the secondary side control, the investment is less than that of the primary side equipment, but in order to reduce the impact on the original control system, it is necessary to add a filter

Therefore, the damping controller used to suppress subsynchronous oscillation generally includes at least a filtering link, a controller gain link and a phase compensation link. The controller structure is relatively complex and the control cost is relatively high

In addition, changes in wind speed, changes in system operation mode, and various sudden failures in the system will cause changes in the system operation state, which may have a certain impact on the controller, thereby limiting the application of the controller and losing the suppression of sub-synchronization Oscillating effect

Images