Rotor Flux Linkage Deadbeat Operation Method of Doubly-fed Wind Turbine Generator

Abstract

The invention discloses a double-fed wind generator rotor flux linkage deadbeat fault operation method. When the grid voltage drops, through the prediction model of the rotor voltage, in order to make the rotor flux follow its given value in the model, the rotor flux is realized. The deadbeat control of the chain needs to replace the value of the rotor flux linkage at the next moment with the given value of the rotor flux linkage at the next moment. The given value of the rotor flux linkage follows the actual value of the stator flux linkage, and the predicted The rotor voltage in the two-phase synchronous rotating coordinate system undergoes coordinate inverse conversion to obtain the rotor voltage in the rotating coordinate system of the two-phase rotor speed, and finally undergoes PWM modulation. The invention has the advantages of simple implementation, good decoupling, fast dynamic response and strong robustness. In the grid fault state, a dead-beat control method for the rotor flux linkage is proposed, which can control the rotor fault current at 1.5-1.6 times the rated value. Within the current, the electromagnetic torque ripple is small during the fault, the dynamic response speed is fast, and the control precision is high.

Description

technical field [0001] The invention belongs to the technical field of doubly-fed wind power generator operation control, and in particular relates to power prediction control in steady state of the power grid and a dead-beat control method for rotor flux linkage when the power grid drops sharply, improving stability in normal operation and doubly-fed in a fault state Fault operation capability of wind turbines. Background technique [0002] In recent years, the electric power industry has developed rapidly in our country and attracted people's attention. With the continuous expansion of the scale of wind farms and the continuous increase of the stand-alone capacity of wind turbines, the penetration rate of wind power in the grid has gradually increased. Although the rapid development has brought considerable economic benefits, it has also caused certain damage to the stability of the power system. The large-scale disconnection of wind turbines caused by grid failure will ...

AI Technical Summary

Problems solved by technology

The first is to achieve fault operation capability by improving the excitation control strategy. This method is suitable for minor faults. In the case of a deep grid voltage drop, this excitation control algorithm is difficult to achieve fault operation control of the power generation system.

The second is the series grid-side converter. This method can realize fault operation under any circumstances, but its connection method is complicated and expensive, and it is rarely used in practical applications.

When the power grid voltage has a single-phase drop of 90% or a three-phase symmetrical drop of 70%, most of the current control methods are difficult to control the rotor current value during the fault period within 2 times of its rated current, and the electromagnetic torque fluctuation is relatively large. The impact force of the unit is great

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