Grid-connected wind farm passivity-based control method

Abstract

The invention discloses a grid-connected wind farm passivity-based control method. The method comprises the steps of 1) building a mathematic model of a current converter of a VSC-HVDC system in an a-b-c three-phase static coordinate system, and through part conversion, obtaining a mathematic model in a d-q synchronous rotation coordinate system; 2) according to a standard form of a PCHD model, building a PCHD model of the VSC-HVDC system, and verifying the passivity of the VSC-HVDC system based on the PCHD model; 3) for the PCHD model of the current converter in the VSC-HVDC system, configuring a desired interconnection and damping matrix according to an IDA-PB control principle, and designing an IDA-PB controller of the current converter in the VSC-HVDC system; and 4) when large disturbance occurs or parameters are inaccurate, generating steady state errors, eliminating the steady state errors by adopting an integrator through utilizing an integral stabilization theorem based on theIDA-PB controller, and keeping global stability of the system. An integral stabilization link is added in the exponentially stable IDA-PB controller. A Lyapunov function is built from a dissipation characteristic of a system energy function; a physical meaning is definite; and an ideal controller can be obtained.

Description

technical field [0001] The invention belongs to the field of smart grids, in particular to a grid-connected control of wind farms. Background technique [0002] In recent years, offshore wind farms have developed rapidly due to their advantages of not occupying land resources and high utilization rate of wind energy. However, the distribution of offshore wind farms is scattered and far away from the main power grid, and the problem of long-distance power transmission has become one of the key issues restricting its development. Due to the intermittent nature of wind power generation and the continuous expansion of wind farm scale, the grid connection of offshore wind farms will have an impact on the power quality of the grid, so it must be paid enough attention to. [0003] With the rapid increase in capacity and cost reduction of fully-controlled power electronic devices, coupled with the opportunities brought about by the vigorous development of wind power and other new e...

AI Technical Summary

Problems solved by technology

At present, the theoretical research on flexible DC transmission has basically been realized in China, but the research on the control method of flexible DC transmission is not deep enough, and there is a lack of simulation experiments, especially in the grid connection of offshore wind farms.

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