Electric power system frequency emergency control method based on dynamic load shedding of doubly-fed wind turbine generator

Abstract

The invention provides an electric power system frequency emergency control method based on dynamic load shedding of a doubly-fed wind turbine generator. The method is used for an electric power system comprising a thermal power generating unit and a high-proportion doubly-fed wind power plant, and solves the technical problem that the frequency modulation capacity and the frequency modulation speed of a synchronous generator set cannot meet the frequency modulation requirement of the system due to violent wind speed fluctuation or large-scale sudden load change in the prior art. The doubly-fed wind turbine generator set has different participation degrees in frequency control of the electric power system in the power interval where the initial active unbalance amount of a power grid is located; different load shedding control methods are adopted for the doubly-fed wind turbine generator in different wind speed intervals according to the predicted wind speed and the target value of theload shedding rate of the doubly-fed wind turbine generator so as to stabilize power grid frequency fluctuation, improve the economical efficiency of the electric power system and provide a theoretical basis for achieving multi-time-scale frequency control over the wind power system.

Description

technical field [0001] The invention relates to the field of wind power control, in particular to an emergency frequency control method of a power system based on dynamic load shedding of double-fed wind turbines. Background technique [0002] In recent years, the penetration rate of wind power has continued to increase, and its randomness has brought new challenges to the power balance and frequency stability of the power system. Doubly-fed generator sets have fast and flexible power regulation capabilities, and are currently the mainstream models of wind power generation. However, the rotor of the doubly-fed wind turbine is decoupled from the grid frequency and cannot provide inertial response when the frequency fluctuates. The integration of large-capacity wind power weakens the overall inertia of the power grid, which leads to the weakening of the frequency control ability of the power grid under disturbances such as wind speed fluctuations and load mutations, and the f...

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Problems solved by technology

[0007] Aiming at the deficiencies of the above-mentioned prior art, the present invention provides a power system frequency emergency control method based on dynamic load shedding of doubly-fed wind turbines, which is used for power systems including thermal power units and doubly-fed wind farms, and solves the problems caused by wind speed in the prior art. The frequency regulation capacity and frequency regulation speed of synchronous generating units caused by violent fluctuations or large-scale sudden changes in loads cannot meet the technical problems of system frequency regulation requirements. According to the power range where the initial active power imbalance of the power grid is located, the degree of participation of doubly-fed wind turbines in power system frequency control Different; according to the predicted wind speed and the target value of the load shedding rate of the DFIG, the DFIG adopts different load shedding control methods in different wind speed ranges to stabilize the frequency fluctuation of the power grid and improve the economy of the power system. System Multi-Time Scale Frequency Control Provides Theoretical Basis

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