Method for suppressing sub-synchronous oscillation of doubly-fed fan with additional damping controller

Abstract

The invention designs a method for suppressing sub-synchronous oscillation of a doubly-fed fan with an additional damping controller, which is applied to control of a rotor side converter of a doubly-fed fan. Parameters need to be configured firstly, then the additional damping controller is introduced into a rotor side converter controller of a doubly-fed fan, the additional damping controller is formed by cascading a band-pass filter, a first-stage gain amplifier and a second-stage gain amplifier, and the parameters of the two stages of amplifiers are determined according to a current inner loop proportionality coefficient of a rotor side converter control system. A rotor side current inner loop current error signal is the input of the damping controller, the output is superposed to an original inner loop output signal, and finally the effect of suppressing sub-synchronous oscillation is achieved. According to the method, extra sampling and measuring links do not need to be added, and the purpose of suppressing sub-synchronous oscillation occurring in a doubly-fed fan series compensation system can be achieved only by utilizing an existing control structure of a current inner loop and slightly improving the control structure.

Description

technical field [0001] The invention relates to the technical field of double-fed fans, in particular to a subsynchronous oscillation suppression method of double-fed fans with an additional damping controller. Background technique [0002] my country's wind energy resources and load centers are distributed in reverse, and long distances limit the large-scale transmission of wind power. Series compensation transmission is one of the economical and effective measures to solve the problem of long-distance power transmission. On the one hand, it can significantly improve line transmission capacity, improve transient stability and operation economy, but on the other hand, there is a risk of inducing subsynchronous oscillation. Several secondary synchronous oscillation accidents of double-fed wind turbines occurred in the Southern Texas Power Grid in the United States and the Guyuan Wind Farm in China, resulting in equipment damage, abnormal noise of the main engine, and wind tur...

AI Technical Summary

Problems solved by technology

The use of flexible DC transmission devices to suppress subsynchronous oscillations requires adding series, parallel or series-parallel hardware devices to the existing power transmission structure. These hardware devices need to be connected to the grid, which has better operational flexibility, but will increase the Land, equipment and post-operation and maintenance investment

To improve the controller design, it is necessary to improve the existing controller to increase the damping of subsynchronous oscillation. In the existing research, the additional damper installed in the DFIG controller often needs to sample and process additional control signals and the parameter configuration is too large. Complicated, the overall design is more inconvenient

For example, CN111181174A discloses a method for suppressing double-fed wind turbine grid-connected sub-supersynchronous oscillation with additional damping control. The method adds a second-order low-resistance filter to suppress its generation in the double-fed wind turbine rotor side converter control link; but the method Parameter configuration is too cumbersome

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