Reactive voltage control and low voltage ride through device and method for wind power generation access power grid

Abstract

The invention provides a reactive voltage control and low voltage ride through device and method for a wind power generation access power grid. The device comprises a data collection device, a control system, a reactive power distribution device, and a voltage and reactive power combined compensation device, wherein the data acquisition device is used for collecting voltage information of the low-voltage side of the transformer substation, and transmits the collected voltage information to the control system; the control system is used for calculating grid-connected point voltage drop amplitude according to the received voltage information, calculating a required reactive power compensation amount according to the calculated grid-connected point voltage drop amplitude, and transmitting the required reactive power compensation amount to the reactive power distribution device; and the reactive power distribution device is used for controlling the voltage and reactive power combined compensation device according to the grid-connected point voltage drop amplitude so as to calculate the required reactive power compensation amount for operation. According to the reactive voltage control and low voltage ride through device and method, fatigue accumulation of devices caused by frequent starting of a Crowbar circuit of a wind turbine generator is avoided, and the voltage stability of the wind power grid-connected point and the low-voltage ride-through capability of the wind turbine generator are improved.

Description

technical field [0001] The invention relates to the technical field of wind power generation systems, in particular to a reactive power voltage control and low voltage ride-through device and method for connecting wind power generation to a power grid. Background technique [0002] With the large-scale integration of wind power into the grid, the control strategy during the voltage drop at the grid-connected point is extremely important for the safe and stable operation of the grid. Power grids in various countries have put forward requirements for low voltage ride through (LVRT) capability for wind farm grid connection. LVRT means that when the voltage of the grid-connected point of the wind farm drops, the wind turbine will continue to provide reactive power support for the grid to return to normal operation without disconnecting from the grid, and then "cross" this low-voltage time zone. For this reason, the wind turbine is equipped with a Crowbar protection circuit. , t...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a reactive power voltage control and low voltage ride-through device and method for connecting wind power generation to the power grid, which solves the above-mentioned shortcomings in the low voltage ride-through of the existing wind turbines

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