Method for improving system damping by using additional damping controller of wind turbine

Abstract

The invention belongs to the field of power systems and in particular relates to a method for modulating the active power output of a wind turbine by using an additional damping controller and improving the low-frequency oscillation damping characteristic of a large-scale wind power station grid-connected system. In the invention, according to a basic principle of controlling the optimum rotary speed of a double-fed wind turbine, a low-frequency oscillation characteristic signal of an alternating current power grid after interference is introduced to design the additional damping controller, the additional damping controller outputs a modulation component for controlling the rotary speed of a fan, and adjustment of the active power output of the wind turbine is realized by controlling the rotary speed of the fan, so an effect of restraining system oscillation is achieved. By applying the method to a large-scale grid-connected wind power station, the low-frequency oscillation damping characteristic of the system after interference can be improved; the system oscillation is quickly restrained; and capability of receiving large-capacity new energy source power of a power grid is improved.

Description

technical field [0001] The invention relates to a method in the field of electric power systems, in particular to a method for using an additional damping controller to modulate a wind turbine to improve the damping characteristic of low-frequency oscillation of a grid-connected system of a large wind farm. Background technique [0002] The potential of wind energy utilization is huge. The total developable installed capacity of onshore and offshore wind energy reaches about 700 to 1.2 billion kW, and the data proposed in the latest assessment report can even reach more than 2.5 billion kW. An important part of the Chinese government's commitment to the development of wind power is to build seven "tens of millions of kilowatts of wind power bases". The seven major wind power bases are located in eastern and western Inner Mongolia, Hami in Xinjiang, Jiuquan in Gansu, Hebei, western Jilin, and the coastal and offshore areas of Jiangsu. With the large-scale development of wind...

AI Technical Summary

Problems solved by technology

However, long-distance and large-capacity power transmission will weaken the system's oscillation damping characteristics. Disturbed by faults or wind power fluctuations, the system is prone to low-frequency oscillations, which endangers the safe and stable operation of the power grid.

By strengthening the transmission network or installing primary devices such as flexible AC transmission, although the oscillation damping of the system can be improved, it will face huge investment

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