The flexible grid-connection research of two-level high-power offshore wind power grid inverter

AbstractThis paper investigates the possibilities of integrating oil and gas platforms and offshore wind power to the onshore power grid. The main motivation for this proposal is to reduce the large greenhouse gas emissions associated with onsite power generation on traditional oil and gas platforms and to improve the economy of offshore wind projects. The feasibility of a hypothetical power system in the North Sea consisting of five oil and gas platforms and one offshore wind power plant with a common connection to the onshore power grid is studied. This combined grid integration concept has not been given much attention in similar previous publications. The connection to the onshore grid is realized through a high-voltage direct current transmission system based on voltage source converter technology. A dynamic simulation model of the system and a control system are presented, and simulations are performed, using SimPowerSystems in MATLAB/Simulink, on system disturbances that are thought to be critical for the operation of the system. The simulation cases represent large disturbances that the system should be designed to withstand. It was concluded that the system handles variations in the load very well and that the system configuration studied in this paper is regarded as a feasible way of integrating oil and gas platforms and offshore wind power to the onshore grid.

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Small-signal modeling and stability analysis of grid-connected offshore wind power based on virtual synchronous generator control

Journal of Physics Conference Series ◽

10.1088/1742-6596/2087/1/012055 ◽

2021 ◽

Vol 2087 (1) ◽

pp. 012055

Author(s):

Lihu Dong ◽

Danqing Song ◽

Zhuo Chen

Keyword(s):

Wind Power ◽

Power Grid ◽

Synchronous Generator ◽

Offshore Wind ◽

System Stability ◽

Design Parameters ◽

Stable Operation ◽

Small Signal ◽

Offshore Wind Power ◽

Grid Connected Inverter

Abstract With the increasing installed capacity of offshore wind power, the grid-connected of offshore wind power technology based on virtual synchronous generators (VSG) control can simulate the inertia and damping characteristics of synchronous generator, which is helpful to improve the networking ability and inertial supportability of grid-connected inverter. However, VSG control also inevitably causes system oscillation, endangers the safe and stable operation of the power grid. Hence, the main circuit and control circuit of offshore wind power grid connection are firstly modeled, and the small-signal model of offshore wind power grid-connected inverter based on VSG control is obtained. Then the correctness of the model is verified by Matlab/Simulink software. Finally, the root trajectory method is used to identify the effects of VSG control parameters and line parameters on the system stability. The results show that VSG control has a significant influence on the stability of the grid-connected system, and reasonable design parameters are needed to ensure the safe and stable operation of the power grid.

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