Harmonic parameter optimization method suitable for offshore wind power transmission system through alternating-current submarine cable network

Abstract

The invention provides a harmonic parameter optimization method suitable for an offshore wind power transmission system through an alternating-current submarine cable network. The method comprises thefollowing steps: constructing a transfer function model of an alternating-current submarine cable network, and constructing a harmonic model and a transfer function model of a wind turbine generator;constructing a network transfer function model considering multiple fans and an alternating current submarine cable network; performing harmonic power flow calculation based on a network transfer function model, further calculating a network transfer function of a harmonic calculation point relative to a harmonic source, analyzing the influence of parameter change on harmonic amplitude accordingto the amplitude-frequency characteristic of the network transfer function, and further reducing the harmonic amplitude by optimizing parameters.

Description

technical field [0001] The invention relates to the establishment of a harmonic model of an offshore wind farm sending system through an AC submarine cable network and a model-based harmonic parameter optimization method. [0002] technical background [0003] Offshore wind farms are usually within 100 kilometers from the coast, so AC submarine cables are commonly used for transmission. Due to the large capacitance of the AC submarine cable to the ground, the equivalent capacitance may resonate with the system reactance parameters. Offshore wind turbines mainly use large-capacity full-power converters for grid connection. The grid-side conversion control system of full-power converters has multiple control links, including phase-locked loops, DC voltage links, and d / q-axis control. Each variable flow control system will respond to harmonic components and there will be complex interactions between variable flow control systems, which will affect the resonance frequency point ...

AI Technical Summary

Problems solved by technology

Due to the large capacitance of the AC submarine cable to the ground, and the equivalent capacitance may resonate with the system reactance parameters

Offshore wind turbines mainly use large-capacity full-power converters for grid connection. The grid-side conversion control system of full-power converters has multiple control links, including phase-locked loops, DC voltage links, and d / q-axis control. Each variable flow control system will respond to harmonic components and there will be complex interactions between variable flow control systems, which will affect the resonance frequency point and cause the resonance to show negative damping or even weak Damping, which in turn leads to high-amplitude harmonics in the system, endangering the safety of electrical equipment and the safe and stable operation of the system

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