Method for controlling active power output of wind power plant and corresponding device

Abstract

The invention provides a method for controlling active power output of a wind power plant and a corresponding device. The method comprises the following steps: when a wind power plant enters a low-voltage ride-through state due to voltage drop of a grid-connected point, determining a maximum active power value allowed to be output by the wind power plant in the current low-voltage ride-through state; determining whether the sum of the active power values currently output by all the wind generating sets of the wind power plant exceeds the determined maximum active power value or not; and, when it is determined that the sum of the active power values exceeds the determined maximum active power value, controlling the wind generating sets to adjust the active power output values, so that the sum of the active power output values of all the wind generating sets does not exceed the determined maximum active power value. According to the method and the corresponding device, it can still be ensured that the wind power plant transmits active power outwards in the low-voltage ride-through period of the wind power plant.

Description

technical field [0001] The present invention generally relates to the technical field of wind power, and more specifically, relates to a method and a corresponding device for controlling active power output of a wind farm. Background technique [0002] Such as figure 1 As shown, the offshore full DC wind farm using parallel medium-voltage DC wind turbines can directly transmit the DC power output by the medium-voltage DC wind turbines to the onshore converter station through the DC transmission line, thereby canceling the offshore converter. Compared with the high-voltage AC transmission scheme with offshore AC booster stations, the platform and large-capacity converter station have greater economic advantages. Among the various topologies of DC wind turbines, DC wind turbines that use AC step-up transformers and diode uncontrolled rectifier bridges as the key links of AC-DC power conversion have broader application prospects due to their good economy and high reliability. ...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problem of ride-through when the voltage drops at the grid-connected point of the onshore AC grid, the existing technology sends a signal for indicating low-voltage ride-through to the offshore DC wind turbine, and the wind turbine reduces the output of the grid-side converter. AC voltage amplitude, so that the voltage input to the rectifier (that is, the diode uncontrolled rectifier bridge) is lower than the rectification voltage threshold of the rectifier, thereby completely blocking the external output active power of the wind turbine, and thus completely blocking the external transmission of active power by the entire wind farm power, this method not only leads to the loss of power generation, but also is not conducive to the operation recovery after the failure of the power grid system

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