Dual-feed asynchronous wind power generator rotor current non-delay control method

Abstract

The invention discloses a nondelay control method for the current of the rotor of the variable speed constant frequency double feed nonsynchronous aerogenerator(DFIG). The transformation of coordinates of static three phase / two phase of the rotational coordinate is finished by collecting three phase rotor current signal so as to obtain the rotor current feedback amount in the static frame of axes to compare with the rotor current command in the stator static frame of axes, the difference signal is input into the proportion-resonance regulator for comparison, the rotor voltage reference value in the stator static fame of axes is obtained after feedback compensation decoupling. The rotor voltage reference value is then transformed into reference signals for space vector pulse width regulation in the rotor frame axes to generate switch signals of the power components of the converter of the rotor to control the synchronize and close operation of the generator. The invention is needless of the break down of the positive and negative sequence of current of the EFIG rotor no matter the electric net voltage is balance or not without introducing break down delay. The invention can realize strengthened control of the generating system in imbalanced electric net, effectively improve non-stop operation of the aerogenerator.

Description

technical field [0001] The invention relates to a method for controlling the rotor current of a wind power generator, in particular to a doubly-fed asynchronous wind power generator (DFIG) rotor suitable for grid voltage balance and unbalance (including small-value steady state and large-value transient unbalance) conditions Current non-delay control method. Background technique [0002] Modern large-scale wind power generation systems mainly include double-fed asynchronous generators (DFIG) and permanent magnet synchronous generators. In order to improve power generation efficiency, variable-speed constant-frequency power generation operations are implemented, and the DFIG system is the current mainstream model. At present, my country's wind power technology mostly stays in the operation control under ideal grid conditions. Since the actual grid often has various symmetrical and asymmetrical faults, it is necessary to carry out research on operation control under grid fault...

AI Technical Summary

Problems solved by technology

In addition to the introduction of delay during separation, the bandwidth of the control system will be affected, which will cause dynamic tracking errors and the dynamic control effect is not ideal

What's more, the circuit can't distinguish whether the grid voltage is balanced or unbalanced. If DFIG operates in a state of strict grid voltage balance, the control system will still use the notch filter to separate the rotor variables, which will bring difficulties to the normal control of the system. Unnecessary delay seriously affects the dynamic control performance of the system

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