A Phase Correction Control Method for No-load Grid-Connected Wind Turbine Generator

Abstract

The invention discloses a no-load grid-connected phase correction control method for a doubly-fed wind power generator. In the no-load grid-connected control process of generators, based on the grid voltage orientation, the grid voltage v qg vs. stator voltage v qs The phase error correction is carried out according to the error relationship of the method. The dynamic response of this method is fast, and the phase tracking can be realized in half a wavelength.

Description

technical field [0001] The invention relates to a no-load grid-connected phase correction control method for a doubly-fed wind generator Background technique [0002] High-performance vector control (co-frequency, co-phase) of doubly-fed wind turbines requires precise rotor position and speed information to the controller. The acquisition of speed generally includes a rotary encoder method and a speed sensorless estimator method. The latter algorithm is complex, and in practical engineering applications, the direct sampling method of the rotary encoder is widely used. For phase control before grid connection, the rotor excitation angular velocity ω is generally considered e =ω s -ω r . In actual engineering, a rotor position error angle Δθ will be generated due to the mechanical installation position of the DFIG relative to the rotor. r ; For discrete control, the delay phase error angle Δθ will be generated due to the step size Ts of the controller d1 ; In addition, ...

AI Technical Summary

Problems solved by technology

The existence of Δθ will lead to severe grid-connected surge current

For grid-connected voltage phase control, people often ignore the composite rotor phase error caused by the mechanical installation position of the doubly-fed motor, the control algorithm, and the channel delay, resulting in a large current grid-connected impact

Therefore, in most cases, people manually compensate the phase error. This trial and error method does not specifically analyze and provide an automatic correction or estimation strategy, which is not smart and fast enough.

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