Prevention and control device and method for cascading failure of large-scale new energy source accessing to power grid

Abstract

The invention discloses a prevention and control device for a cascading failure of a large-scale new energy source accessing to a power grid, which comprises a battery energy storage unit, a normally open relay, a normally closed relay, a step-down chopper circuit, a step-up chopper circuit, an end capacitor, a current transformer and a power smoothing device which are connected. The device exists in each transmission line to which the new energy source accesses. The invention also discloses a prevention and control method for a cascading failure of a large-scale new energy source accessing to a power grid. An intelligent PI controller is used to adjust the output power of the wind turbine to each transmission line in a closed-loop manner so as to effectively reduce the load factor of the high-risk line and to ensure the load factor of other lines remained below the heavy load threshold, thereby improving the distribution of tidal currents and playing a preventative role of the cascading failure.

Description

technical field [0001] The invention belongs to the technical field of power system operation control, and in particular relates to a large-scale new energy access grid cascading failure prevention control device and method. Background technique [0002] With the deepening of grid interconnection and the access of large-scale new energy sources, while achieving greater economic benefits, the overall security of the grid has been seriously affected. The randomness and volatility of large-scale new energy may play a role in fueling some failures of local power grids, thereby inducing cascading failures, leading to large-scale power outages and even the collapse of the power grid. Therefore, how to prevent the occurrence of cascading failures has become a research topic that is widely concerned by scholars at home and abroad. [0003] However, most of the current research on the prevention and control strategies of cascading failures is based on traditional power grids (exclud...

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Problems solved by technology

[0007] The purpose of the present invention is to solve the problem of uneven power flow distribution in the power grid under the background of large-scale wind power centralized access, and to provide a power grid cascading failure prevention and control device and method under the background of large-scale new energy access. The output of each transmission line can effectively reduce the load rate of high-risk lines, and at the same time ensure that the load rate of other lines is maintained below the heavy load threshold, improve the power flow distribution, and prevent cascading failures.

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