Self-synchronizing voltage source wind turbine generator with synchronous generator supporting power grid operation

Abstract

The invention discloses a self-synchronizing voltage source wind turbine generator with a synchronous generator supporting power grid operation, a control unit autonomously perceives the frequency change of the power grid and combines the inertia response of the synchronous generator, and a machine side converter controls the wind turbine generator to cooperate with the synchronous generator in the power grid to complete the optimal inertia response; a wind turbine generator maximum power tracking control unit considering inertia response designs a dynamic compensation algorithm by combining the relationship between the rotating speed and the rotational inertia of a wind turbine and the wind energy utilization efficiency in three operation stages of a wind turbine generator, so that the wind energy utilization efficiency and the inertia response effect are comprehensively optimal; an off-grid independent operation control unit controls a machine-side converter to cooperate with a unit variable pitch system by autonomously sensing the voltage change of a wind turbine generator port so as to complete the real-time balance of the output of the wind turbine generator and the power of a load. And a seamless switching control unit in the grid-connected and off-grid switching process controls the stability of the port voltage of the wind turbine generator in the grid-connected and off-grid switching process through a terminal voltage consistency control algorithm.

Description

technical field [0001] The present invention relates to the technical field of electrical engineering, in particular to a self-synchronous voltage source wind turbine for a synchronous generator supporting the operation of a power grid. Background technique [0002] In recent years, with the continuous development of wind power generation technology, the penetration rate of wind power has continued to increase. Wind farms are connected to the grid through long-distance transmission lines, which makes there is a weak connection between wind turbines and the grid. In this case, the traditional based The dynamic performance of the converter controlled by the grid voltage-oriented vector control strategy of the phase-locked loop deteriorates, and it is easy to interact with the grid such as harmonic oscillation; at the same time, a large number of new energy sources lead to the lack of grid system inertia, resulting The frequency of the system changes drastically under load fluc...

AI Technical Summary

Problems solved by technology

[0002] In recent years, with the continuous development of wind power generation technology, the penetration rate of wind power has continued to increase. Wind farms are connected to the grid through long-distance transmission lines, which makes there is a weak connection between wind turbines and the grid. In this case, the traditional based The dynamic performance of the converter controlled by the grid voltage-oriented vector control strategy of the phase-locked loop deteriorates, and it is easy to interact with the grid such as harmonic oscillation; at the same time, a large number of new energy sources lead to the lack of grid system inertia, resulting Under load fluctuations, the system frequency changes drastically, endangering the safe and stable operation of the power network

[0003] On the other hand, when the grid load changes and the system frequency deviates from the normal range, the converter based on phase-locked loop control cannot respond to the grid frequency change like a traditional synchronous generator, and the overall inertia of the system is reduced, increasing the grid frequency adjustment. difficulty

When there is a large disturbance in the power grid, the system frequency stability will be seriously affected

In addition, traditional phase-locked loop-based converters cannot operate independently with load

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