Distributed wind power low voltage ride through and anti-islanding protection coordination control strategy

Abstract

The invention discloses a distributed wind power low-voltage ride-through and anti-islanding protection coordination control strategy which comprises the following steps: 1) a wind turbine generator runs normally, the voltage of a grid-connected point is monitored in real time, when the voltage of the grid-connected point is lower than 0.9, the wind turbine generator enters a low-voltage ride-through mode, the minimum voltage drop depth Vdip and the corresponding time thereof are recorded, and if the Vdip is smaller than 0.2, the step 4) is executed; if Vdip is greater than or equal to 0.2 and less than 0.5, executing the step 3); if Vdip is greater than or equal to 0.5 and less than 0.9, executing the step 2); (2) the wind turbine generator runs in a low-voltage ride-through mode, reactive current support is provided to help power grid voltage recovery, and if the voltage recovers to be normal, the step (1) is executed; otherwise, executing the step 4); (3) judging whether the voltage is recoverable or not when the wind turbine generator runs in a low-voltage ride-through mode, and executing the step (2) if the voltage is recoverable; if the voltage is unrecoverable, executing step 5); (4) the wind turbine generator is cut off through a low-voltage ride-through protection action; and (5) the wind turbine generator is cut off through an anti-islanding protection action.

Description

technical field [0001] The invention relates to the technical field of wind power, in particular to a coordinated control strategy for low-voltage ride-through and anti-islanding protection of distributed wind power. Background technique [0002] Vigorously developing wind power is an important strategic measure to build a clean, low-carbon, safe and efficient energy system in my country. The main characteristics of my country's wind power development are "large-scale centralized development and long-distance ultra-high voltage transmission". At the same time, the state also encourages the development of distributed wind power to achieve multi-point access and local consumption. As more and more large-scale wind power is connected to the grid, the power grid requires that wind turbines must change their roles from passive adaptation to active support and active networking. There is a certain contradiction between the Low Voltage Ride Through (LVRT) requirements of distribu...

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Problems solved by technology

[0004] The present invention mainly aims to solve the problem that the existing technology does not really realize the coordinated control of low-voltage ride-through and anti-islanding protection, and provides a coordinated control strategy for distributed wind power low-voltage ride-through and anti-islanding protection, which is selected according to the actual voltage development trend. The action logic can not only avoid the frequent disconnection of wind turbines due to transient voltage faults, but also ensure the power generation of wind turbines, and avoid frequent switching of wind turbines from causing multiple impacts on the power grid; it can also avoid passive low-voltage ride-through processes such as permanent voltage faults. Accidents caused by

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