Fault voltage ride-through control method and system for doubly-fed wind generator

Abstract

The invention discloses a fault voltage ride-through control method and system for a doubly-fed wind generator, and the method comprises the steps: obtaining a three-phase current of a doubly-fed wind generator rotor, and carrying out the coordinate transformation of the three-phase current, and obtaining a DC component; obtaining a d-axis current instruction value according to the dynamic voltage instruction value; obtaining a q-axis current instruction value based on the active instruction value of the maximum wind energy tracking control; and performing current loop adjustment on the direct current component, the d-axis current instruction value and the q-axis current instruction value to obtain a modulation signal, and generating a driving signal of a rotor side converter switching tube according to the modulation signal so as to control fault voltage ride-through of the doubly-fed wind generator. A control voltage instruction value can be dynamically changed so as to realize reactive power exchange between a wind turbine generator and a power grid, and the high-voltage and low-voltage fault ride-through capability of the double-fed asynchronous wind generator DFIG is improved.

Description

technical field [0001] The invention relates to the technical field of wind power generator converter control, in particular to a doubly-fed wind power generator fault voltage ride-through control method and system. Background technique [0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] In recent years, with the continuous increase of the proportion of wind power in the power grid, the installed capacity of wind power has reached a relatively high level. If the wind turbines do not have a certain ability to resist grid faults, passive protection solutions are still adopted when the grid voltage fails. It will increase the difficulty of fault recovery of the entire system, and may even worsen the safety and stability of the power grid, which will eventually cause a chain reaction and cause the system to collapse. Therefore, effective control measures must be taken...

AI Technical Summary

Problems solved by technology

Although this high-voltage ride-through method can meet the requirements of the wind power grid-connected code for the high-voltage ride-through capability of the unit during the voltage increase process, the implementation is relatively cumbersome, and the control mode needs to be switched based on the calculated overvoltage criterion.

[0006] The inventor believes that the above-mentioned schemes propose different solutions for the fault ride-through of wind turbines, but they all have certain limitations, that is, only a single fault ride-through can be achieved, and the two goals of high and low voltage ride-through cannot be achieved at the same time. The unification of control strategies during voltage swells and sags is relatively complex, or requires coordinated control with the power grid, or requires control mode switching, and the economic cost is higher

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