Fault overload control method for wind turbine delivery system based on acceleration of doubly-fed wind turbine generator system

Abstract

The invention provides a fault overload control method for a wind power delivery system based on acceleration of a doubly-fed wind turbine generator system, which comprises the following steps of: calculating AC delivery line power flow overload Delta Pd and calculating maximum controllable active power output Delta Pwm of a doubly-fed wind farm, thereby proposing the acceleration controllable range of doubly-fed wind turbine generator system; when Delta Pd <= Delta Pwm, calculating the active power control quantity Delta Pgi of each doubly-fed wind turbine; when Delta Pd > Delta Pwm, settingthe active power control quantity of each doubly-fed wind turbine as its maximum controllable active power output Delta Pgmi, and when Delta Pd > Delta Pwm, setting the active power control quantity as its maximum controllable active power output Delta Pgmi; calculating the rotational speed control reference value omega'ri* of each doubly-fed wind turbine unit according to the active power controlquantity; locking the rotor-side converter control outer loop of the doubly-fed wind turbine, and directly giving the reference value irqi* of the active current of the inner loop. The invention cangive full play to the active power control ability of the doubly-fed wind turbine generator system, and rapidly reduce the active power output of the doubly-fed wind farm, thereby avoiding the cascading tripping caused by the overload of the AC delivery line.

Description

technical field [0001] The invention relates to the field of wind power control, in particular to a fault overload control method for a wind power delivery system based on the acceleration of double-fed wind turbines. Background technique [0002] For areas where wind energy resources and load centers are reversely distributed, wind power development generally adopts a large-scale centralized development and long-distance high-voltage transmission mode. Due to the large transmission capacity and long transmission distance of the HVDC transmission system with commutation converters in the power grid, the transmission of wind power through conventional DC has become the main way for the cross-regional optimal allocation of wind energy resources. However, the construction of high-voltage DC transmission projects is significantly ahead of the high-voltage AC transmission projects, making the current AC-DC hybrid system present typical strong DC and weak AC characteristics. Conv...

AI Technical Summary

Problems solved by technology

Some studies have proposed to transform the power angle stability problem caused by power flow transfer into the frequency stability problem of the sending-end grid through DC back-to-back asynchronous interconnection. However, due to the large-scale wind turbine replacing the conventional generator set, the inertia of the sending-end grid is reduced, and it cannot respond quickly frequency change

Some studies have improved the controllers of conventional DC rectifier stations so that they can participate in the frequency control of the power grid at the sending end. However, in the c

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